CONTEK PTY LTD (ACN 135 978 853) v MOSSOP GROUP PTY LTD (ACN 008 018 540) [2024] SADC 1

Applicant: CONTEK PTY LTD (ACN 135 978 853) Counsel: MR P ADAMS - Solicitor: CHARLTON ROWLEY Respondent: MOSSOP GROUP PTY LTD (ACN 008 018 540) Counsel: MR R ROSS-SMITH - Solicitor: FBR LAW Hearing Date/s: 05/09/2022 to 09/09/2022, 13/09/2022, 24/11/2022, 09/12/2022, 12/12/2022, 21/12/2022 File No/s: DCCIV-18-629 B DISTRICT COURT OF SOUTH AUSTRALIA (Civil) DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment. The onus remains on any person using material in the judgment to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court in which it was generated. CONTEK PTY LTD v MOSSOP GROUP PTY LTD [2024] SADC 1 Judgment of her Honour Judge Thomas 15 January 2024 CONTRACTS - BUILDING, ENGINEERING AND RELATED CONTRACTS - PERFORMANCE OF WORK CONTRACTS - BUILDING, ENGINEERING AND RELATED CONTRACTS - THE CONTRACT - CONSTRUCTION OF PARTICULAR CONTRACTS AND IMPLIED CONDITIONS - VARIATIONS CONTRACTS - BUILDING, ENGINEERING AND RELATED CONTRACTS - THE CONTRACT - CONSTRUCTION OF PARTICULAR CONTRACTS AND IMPLIED CONDITIONS - DETERMINATION OF COST EQUITY - GENERAL PRINCIPLES - MISTAKE - EQUITABLE REMEDIES The Applicant (Contek) carried out concreting works for the Respondent builder (Mossop) for two unrelated commercial building projects under bespoke subcontracts made in late 2015 for the Aldi project and 2016 for the Lifecare project respectively. Disputes arose during the course of both projects over numerous variation claims. Proceedings were instituted in June 2018 by Contek claiming damages for unpaid variation claims. Mossop counterclaimed entitlement to set off back charges for various items. The first part of the trial was adjourned for Contek to amend to introduce a new cause of action for rectification of the Lifecare subcontract and in the further alternative, claims for misleading and deceptive conduct and unconscionability under ss 18, 20 and 21 of the Australian Consumer Law for its extra steel variation claims. Ultimately, the Court was required to determine 13 discrete claims involving a wide range of factual and evidentiary issues. The most significant and complex claims concerned Contek’s variation claims for extra concrete and steel for the Lifecare project. -- 1 of 106 -- Questions considered as to the proper basis of assessing and valuing variation and back charge claims, the existence and scope of instructions and directions to vary works, the contractual process for claiming variations and non-compliance with notice provisions and betterment. Observations made as to the proper basis for fact finding, whether unpleaded claims and defences should be permitted to be agitated at trial and the inferences arising from failure to call relevant witnesses or adduce relevant evidence from testifying witnesses. Held: 1. Judgment for Contek in the amount of $40,655.18 ex GST for its variation claims V2, V6 and V8 (extra concrete) net of the amounts assessed and paid. The fullest and best evidence of the additional Helix fibre concrete required is the volume of concrete supplied to site as proven by the Hanson delivery dockets less a fair and reasonable allowance for the volume of standard concrete measured by the concrete drawings as adjusted for volumes for joints, infills, fillings and 160mm slabs as measured by the project quantity surveyor. 2. Judgment for Contek on its claim for rectification of the Lifecare subcontract to list in Appendix D revision 00 for structural drawings S04, S05 and S23. 3. Judgment for Contek in the amount of $27,007.66 ex GST for its Lifecare project variation claims V7 and V9 (extra steel reinforcing) net of the amount assessed and agreed to be paid. There was a material change between the Tender and Contract Drawings as to the volume of steel reinforcing required for the planter box edges to the first and second floor slabs. The OneSteel variations to its supply contract with Contek are a fair and reasonable basis for valuing the variation claims. 4. As for Mossop’s Lifecare project back charge claims, judgment for Mossop in the amounts of $4,500,00 ex GST for claim B5 (Patch & Caulk – Balcony Works). $4,359.50 ex GST for claim B11 (Basement Repairs) and $10,000 ex GST for claim B13 ( Partial Rectification to Basement Works). Mossop’s back charge claim B10 (TC Formwork to Beam Above Ramp) is dismissed. 5. Judgment for Contek in the amount of $5,690.00 for its Aldi project variation claim B2.0 (cast- in angles & slab redesign) net of the amount assessed and agreed to be paid. 6. Mossop’s back charge claim B1 (absence from the Aldi project site) is dismissed. 7. As to the disputed settlement amounts, Mossop’s contention that the parties’ settlement agreement covers the entirety (and not just the disputed component) of amounts claimed by Contek for its Aldi variation claims B1.0 (cancelled concrete pour) and B3.1 (pylon sign pad footing) is rejected. Judgment for Contek in the amount of $4,192.50 ex GST for claim B3.1 (pylon sign pad footing). Although Contek’s claim B1.0 (cancelled concrete pour) was not settled, it is dismissed as unproven. Australian Competition and Consumer Act 2010 (Cth), Australian Consumer Law sch 2, ss 18, 20, 21, referred to. Simic v NSW Land and Housing Corporation (2016) 260 CLR 85, applied. Australasian Performing Right Association Ltd v Austarama Television Pty Ltd [1972] 2 NSWLR 467; Bellgrove v Eldridge (1954) 90 CLR 613; BCI Finances Pty Ltd (in liq) v Binetter (No 4) (2016) 348 ALR 227; Commonwealth v Jennings Construction Ltd [1985] VR 586; Demagogue Pty Ltd v Ramensky (1992) 39 FCR 31; Diploma Construction Pty Ltd v Marula Pty Ltd [2009] WASCA 229; Ho v Powell (2001) 51 NSWLR 572; Jones v Dunkel (1959) 101 CLR 298; Mann v Paterson Constructions Pty Ltd (2019) 267 CLR 560; Maralinga Pty Ltd v Major Enterprises Pty Ltd (1973) 128 CLR 336; Mount Bruce Mining Pty Ltd v Wright Prospecting Pty Ltd (2015) 256 CLR 104; NRM Corporation Pty Ltd v ACCC [2016] FCAFC 98; Ritz Hotel Ltd v Charles of the Ritz Ltd (No 7) (1987) 14 NSWLR 104, considered. -- 2 of 106 -- CONTEK PTY LTD v MOSSOP GROUP PTY LTD [2024] SADC 1 PART A: INTRODUCTION ..................................................................................................................... 4 PART B: THE TRIAL................................................................................................................................ 4 PART C: THE EVIDENCE ....................................................................................................................... 7 The Witnesses Generally ............................................................................................................................ 9 The Witnesses Called .................................................................................................................................. 9 Mr Apostolakos ........................................................................................................................................ 9 Mr Stringer ............................................................................................................................................ 10 Mr Orlovic .............................................................................................................................................. 10 Mr Mossop ............................................................................................................................................. 11 Mr Lalli .................................................................................................................................................. 11 Mr McFarlane ....................................................................................................................................... 12 Witnesses Not Called ................................................................................................................................ 12 Mr Kemp ................................................................................................................................................ 12 Mr Barone .............................................................................................................................................. 12 Mr Zilic .................................................................................................................................................. 12 Mr Tziortzis ............................................................................................................................................ 13 PART D: LIFECARE PROJECT – TOPIC 3 - EXTRA CONCRETE .............................................. 13 The Dispute – $58,008.38 ex GST ............................................................................................................ 13 The Variation Claims ............................................................................................................................ 13 Claimed Additional Volumes................................................................................................................. 14 The Parties’ Contentions .......................................................................................................................... 16 The Pleadings ........................................................................................................................................ 16 The Parties’ Contentions at Trial ......................................................................................................... 18 The Issues to be Determined ................................................................................................................. 19 The Evidence ............................................................................................................................................. 23 The Topping Slab Works ....................................................................................................................... 23 Mossop’s Assessment ............................................................................................................................. 25 Set-Down Measurements....................................................................................................................... 29 The Alexander Symonds Survey ........................................................................................................... 32 Evidence of Inconsistency in Deltacore Floor ..................................................................................... 35 QS Assessments...................................................................................................................................... 38 The Issues Answered................................................................................................................................. 40 Issue 1: Was there an instruction or direction constituting a variation? .......................................... 40 The Implications of any Answer ........................................................................................................... 40 The Parties’ Cases ................................................................................................................................. 41 Change in Concrete Mix ....................................................................................................................... 41 On-site Direction to Vary ...................................................................................................................... 43 Breakouts ............................................................................................................................................... 49 Issue 2: Are these variation claims contractually barred?.................................................................... 49 The Subcontract Variation Provisions.................................................................................................. 49 -- 3 of 106 -- [2024] SADC 1 2 Consideration ......................................................................................................................................... 51 Conclusion ............................................................................................................................................. 52 Issue 3: Is the Alexander Symons survey result binding? .................................................................... 52 Consideration ......................................................................................................................................... 52 Conclusion ............................................................................................................................................. 53 Issue 4: Was Contek’s standard concrete allowance adequate? ......................................................... 53 The Parties’ Contentions ....................................................................................................................... 53 Evidence of Take-offs ............................................................................................................................ 55 10% Wastage Allowed ........................................................................................................................... 56 Allowance for Joints, Infills or Fillings ............................................................................................... 57 Allowance for 160mm Slabs .................................................................................................................. 58 Allowance for 400mm Slabs .................................................................................................................. 58 Tender or Contract Drawings? ............................................................................................................. 59 Conclusion ............................................................................................................................................. 59 Issue 5: What is a fair and reasonable measure for any additional concrete? ................................... 60 Consideration and Conclusion .............................................................................................................. 60 PART E: LIFECARE PROJECT – TOPIC 4 - EXTRA STEEL ....................................................... 62 The Dispute – $27,007.66 ex GST ............................................................................................................ 62 The Variation Claims ............................................................................................................................ 62 Mossop’s Assessment ............................................................................................................................. 63 The Lifecare Subcontract ...................................................................................................................... 65 The Parties’ Contentions ....................................................................................................................... 66 The Issues................................................................................................................................................... 67 Issue 1: Should the Lifecare subcontract be rectified?.......................................................................... 67 Relevant Legal Principles ...................................................................................................................... 67 The Evidence.......................................................................................................................................... 68 Conclusion ............................................................................................................................................. 78 Issue 2: Did Mossop mislead Contek about the Contract Drawings? .................................................. 78 Issue 3: Was there any material change between the Tender and Contract Drawings? ................... 79 The Drawings......................................................................................................................................... 79 Changes to the Reinforcing ................................................................................................................... 80 Conclusion ............................................................................................................................................. 81 Issue 4: What is the fair and reasonable value of the variation claimed? ........................................... 81 OneSteel Documents.............................................................................................................................. 81 Conclusion ............................................................................................................................................. 84 Issue 5: Are these variation claims contractually barred?.................................................................... 84 Consideration ......................................................................................................................................... 84 Conclusion ............................................................................................................................................. 84 Overall Conclusion.................................................................................................................................... 85 PART F: LIFECARE PROJECT – TOPIC 7 – BACK CHARGE CLAIMS ..................................... 85 The Disputes – Back Charge Claims B5, B10, B11 & B13 .................................................................... 85 B5 – Patch & Caulk Balcony Works Back Charge - $10,990.90 ex GST............................................. 85 -- 4 of 106 -- [2024] SADC 1 3 B10 – TC Formwork to Beam Above Ramp – Back Charge - $3,837.00 ex GST ............................... 88 B11 – Basement Repairs – Back Charge - $4,359.50 ex GST ............................................................... 90 B13 – Partial Rectification of Basement Works – Back Charge - $12,000.00 ex GST ....................... 90 The Issues .............................................................................................................................................. 90 Inadequate Fall on Spoon Drains......................................................................................................... 91 Direction to Pour in Wet Weather ........................................................................................................ 91 Betterment .............................................................................................................................................. 94 Conclusion ............................................................................................................................................. 95 PART G: ALDI PROJECT – TOPIC 10 – CAST IN ANGLES .......................................................... 95 Disputed Value - $5,760.00 ex GST ......................................................................................................... 95 PART H: ALDI PROJECT – TOPIC 11 – ABSENCE FROM SITE.................................................. 98 Disputed Back Charge - $9,626.36 ex GST ............................................................................................. 98 The Christmas Closure .......................................................................................................................... 98 The Relevant Program........................................................................................................................... 99 Conclusion ........................................................................................................................................... 100 PART I: SETTLEMENT DISPUTE ..................................................................................................... 100 Issues in Dispute – Aldi Project Variation Claims B1.0 and B3.1 ...................................................... 100 PART J: FORM OF JUDGMENT AND JUDGMENT SUM ........................................................... 103 PART K: COSTS ................................................................................................................................... 104 -- 5 of 106 -- [2024] SADC 1 4 PART A: INTRODUCTION 1 This proceeding concerns disputed variation and back charge claims under two subcontracts between the same parties for concrete works for unrelated building projects. One project concerns a two-storey aged care facility in Joslin known as the Lifecare Roselin Court Stage 1 (Lifecare) Project. The second concerns the Aldi supermarket at Berri (Aldi) Project. 2 The Applicant, Contek Pty Ltd (Contek), is a building contractor specialising in the supply of civil and concreting works for commercial projects. The Respondent, Mossop, carries on business as a licensed builder and was the principal building contractor for the Lifecare and Aldi Projects. 3 The Lifecare subcontract1 was in writing and made in October 2016 for concrete works involving the supply of labour and materials for the footings and the slabs for the basement, ground, first and second floors and the stairs for the Lifecare Project in consideration of a fixed lump sum subcontract price of $1,092,180.00 ex GST.2 4 The Lifecare subcontract works the subject of dispute were carried out in late 2016 and 2017. 5 The Aldi Project was first in time. The Aldi subcontract3 was in writing and made in October 2015. It concerned a lesser scale of concrete works for development of a supermarket involving the supply of labour and materials for the concrete slab and footings of the main supermarket building, with in-situ retaining wall footings and walls and external concrete pavement in consideration of a fixed lump sum price of $546,500.00 ex GST.4 6 The Aldi subcontract works were carried out in late 2015 and early 2016. 7 Proceedings were instituted in June 2018 claiming Contek was entitled to be paid by Mossop for unpaid invoiced amounts for both of the Lifecare and Aldi subcontract works as allegedly varied. Mossop counterclaimed entitlements to set off back charges for various items. The parties narrowed some of the issues in dispute during the interlocutory stages of the proceeding and during the course of the trial. PART B: THE TRIAL 8 The trial was heard in parts in November 2021 and in September, November and December 2022. The first part took place over two and half days and was adjourned following Contek’s application to amend its claim to introduce causes of action for rectification of the Lifecare subcontract, misrepresentation and 1 Exhibit A1 page 182. 2 $1,201,398.00 inc GST. 3 Exhibit A8 page 5. 4 $601,150.00 inc GST. -- 6 of 106 -- [2024] SADC 1 5 unconscionable conduct as regards Contek’s claimed variations for extra steel for the Lifecare project.5 9 The second part of the trial proceeded over seven days on revised pleadings that do not define the real issues in dispute with clarity.6 Further concessions were made by both parties during the adjourned trial, further reducing the scope of the issues to be determined by the Court and the quantum in dispute. By the end of the trial the parties agreed it was only necessary for the Court to determine the discrete claims set out in the following table. Table 1 No. Description Claimed Value ex GST Agreed Value ex GST Disputed Value ex GST LifeCare Project V2 Extra Concrete – Ground Floor $36,217.97 $4,977.00 $31,240.96 V6 Extra Concrete – First Floor $26,973.24 $13,250.59 $13,722.65 V7 Extra Steel – First Floor $14,031.68 $527.857 $13,503.83 V8 Extra Concrete – Second Floor $18,590.52 $5,545.76 $13,044.77 V9 Extra Steel – Second Floor $14,031.68 $527.858 $13,503.83 B5 Patch & Caulk – Balcony Works -$10,990.90 Nil -$10,990.90 B10 TC Formwork to Beam Above Ramp -$3,837.00 Nil -$3,837.00 B11 Basement Repairs -$4,359.50 Nil -$4,359.50 B13 Partial Rectification to Basement Works -$12,000.00 Nil -$12,000.00 Total $78,657.69 $23,773.35 $53,828.64 Aldi Project B2.09 Cast-in Angles & Slab Redesign $14,890.00 $9,130.00 $5,760.00 B1 Absence from Site -$9,626.36 -$9,626.36 Total $5,263.64 $9,130.00 -$3,866.36 Grand Total $83,921.33 $32,903.35 $49,962.28 5 See Topic 4 below. 6 Amended Third Statement of Claim dated 1 March 2022 (FDN 66) (the Claim); Amended Third Defence and Counterclaim dated 5 April 2022 (FDN 67) (the Defence and Counterclaim); Reply to Third Defence and Second Defence to Counterclaim (Revision 3) dated 21 June 2022 (FDN 72) (the Reply and Defence to Counterclaim). 7 See [348] below. 8 Ibid. 9 Sometimes referred to as V2.0. -- 7 of 106 -- [2024] SADC 1 6 10 As can be seen from the disputed amounts in Table 1 above, the complexity and number of the issues ultimately in dispute and the litigation costs involved were disproportionate to their value from the outset. 11 It is convenient to determine the claims before the Court in the way they were grouped and presented by project and ‘topic’. • The most significant claim is Contek’s variation claims for extra concrete for the Lifecare Project (V2, V6 and V8), referred to as Topic 3. • Next in significance is Contek’s variation claims for extra steel for the Lifecare Project (V7 and V9), referred to as Topic 4. • Mossop’s back charge claims for patching and caulking works (B5), formwork to the beam above the ramp (B10), basement repairs (B11) and partial rectification and repairs (B13) for the Lifecare Project were part of Topic 7. • Contek’s variation claim for cast-in angles and slab redesign for the Aldi Project (B2.0 or V2.0) was referred to as Topic 10. • Mossop’s back charge claim for Contek’s absence from site for the footings pour (B1) was referred to as Topic 11. 12 Contek prepared an aide memoire in the course of the trial summarising the impact of the parties’ agreed and differing positions as to the disputed variation and back charge claims on the adjusted subcontract sums allegedly due net of payments made by Mossop (either to Contek or into Court) under each of the Lifecare and Aldi subcontracts. This aide memoire was in the form of a spreadsheet that underwent a number of iterations (both as MFI A12 then MFI A19) to which Mossop took various objections as to its accuracy. The dispute between the parties was made all the more difficult because of their inconsistent use of GST exclusive and inclusive figures. 13 In the parties’ written closing submissions, Contek relied on a final iteration of MFI A19. In response, Mossop relied on its own summary for each project (Tables 1 and 2) and full project summaries (Appendix 1). Whilst there was a significant degree of common ground, despite the Court urging the parties to agree a single form of spreadsheet both during the trial and after oral submissions were made, the parties were unable to do so. 14 It was at this stage of the proceeding that a further dispute arose between the parties about what had been agreed in resolving a number of variation and back charge claims during the trial. This led to two further short hearings and further affidavit evidence being filed. As a result, the Court is required to determine a further dispute about the parties’ alleged agreement concerning two further variation claims for the Aldi Project as set out in Table 2 below. The conceded -- 8 of 106 -- [2024] SADC 1 7 values are the disputed amounts shown in the aide memoires MFI A12 and MFI A19 as a result of the concession made by Contek’s counsel that it would abide by the Court’s determination of this dispute and not press the balance of its claim that it forwent in the settlement agreement.10 Table 2 No. Description Claimed Value ex GST Conceded Value ex GST Disputed Value ex GST Aldi Project B1.011 Cancelled Concrete Pour $6,640.00 -$2,123.45 $4,516.55 B3.112 Pylon Sign Pad Footing $5,151.36 -$958.86 $4,192.50 PART C: THE EVIDENCE 15 The tender book comprised 13 volumes following orders made before the first part of the trial that it be compiled by topic of dispute. This led to significant duplication between the volumes, and a well-justified complaint by Contek that the exercise was unhelpful and added complexity and difficulty in preparing and conducting the trial. Contek’s counsel expressly reserved Contek’s rights in terms of costs on the first day of trial.13 16 Each volume of the tender book was accompanied by a lengthy ‘narrative’ that served as a commentary on the relevant topic from Mossop’s point of view as well as an index to the documents relied on. The narratives were in the nature of submission and the Court was invited to treat them as part of both Mossop’s opening and closing submissions. Although they were largely repetitive of Mossop’s closing written submissions, there were some material differences reflecting shifts in Mossop’s case over time in long running proceedings. 17 Both parties relied on lengthy written closing submissions which were supplemented orally. Contek objected to Mossop’s closing written submissions reading like an expert’s report, with detailed drawings marked up with notes and accompanying commentary and annexures that were not tendered at trial or put to any witnesses. Contek’s objections were not unreasonably made and the Court, as it is obliged to do, has reviewed both Mossop’s submissions and the documentary evidence carefully, bearing in mind the pleaded issues in dispute and the fundamental principles concerning fact-finding. 10 T851.9-.10. 11 Sometimes referred to as V1.0. 12 Sometimes referred to as V3.1. 13 15 November 2021, T2.9-3.17. -- 9 of 106 -- [2024] SADC 1 8 18 In this regard, much was said by both parties about the other’s failure to prove elements of their case or call witnesses who could have given evidence about relevant facts. Not only were some witnesses not called and their absence unexplained, but some of the witnesses who were called were not questioned on topics that they could have given evidence about that would have assisted the Court resolve some issues. Taking a generous view, in part this was the product of the disproportion between the value of the claims in dispute and the costs of litigation and each party doing its best to prove its claims as economically as could be done. 19 In determining the issues in this case, the Court has borne in mind the following principles. 20 This Court in deciding facts according to the civil standard of proof must decide what are the probabilities on the evidence before the Court and where the evidence is limited and unsatisfactory, whether it is an appropriate basis on which to reach a reasoned conclusion. It is in dealing with this second issue that the Court is to have regard to the ability of the parties, particularly the party bearing the onus of proof to lead evidence on a particular matter, and the extent to which they have in fact done so.14 21 It is also pertinent in face of the many Jones v Dunkel objections taken in this case to emphasise that the absence of a witness is “only significant where the evidence which such a person is expected to give would (not might) elucidate a particular matter in issue.”15 As explained by the High Court in Jones v Dunkel:16 [A]ny inference favourable to the plaintiff for which there was ground in the evidence might be more confidently drawn when a person presumably able to put the true complexion on the facts relied on as the ground for the inference has not been called as a witness… 22 It follows that there first must be some existing basis in the evidence to support the inference one party contends should be drawn before the absence of evidence from the opposing party is significant. As clarified in Cross on Evidence:17 Thirdly, the rule only applies where a party is “required to explain or contradict” something. What a party is required to explain or contradict depends on the issues in the case as thrown up in the pleadings and by the course of evidence in the case. No inference can be drawn unless evidence is given of facts “requiring an answer”. If there is no issue between the parties on a matter, there is nothing to answer; and if there is an issue between them, but the party bearing the burden of proof has tendered no evidence of it, the opponent is not required to answer. Where it is not established that an admission was made by one employee rather than another, there is nothing to explain or contradict in relation to the first employee. 14 Ho v Powell (2001) 51 NSWLR 572 at [14]-[15]. 15 BCI Finances Pty Ltd (in liq) v Binetter (No 4)(2016) 348 ALR 227 at [127] per Gleeson J. 16 (1959) 101 CLR 298 at 308 per Kitto J. 17 J D Heydon Cross on Evidence (LexisNexis Butterworths, 12th ed, 2020) at [1215]. Footnotes omitted. -- 10 of 106 -- [2024] SADC 1 9 The Witnesses Generally 23 The events the subject of this dispute are dated, occurring between five and seven years before the witnesses gave evidence. The Aldi Project concrete works were carried out first between about December 2015 and May 2016. The Lifecare Project works were carried out between about December 2016 and mid-2017. 24 Witnesses understandably had difficulties recalling matters and were generally frank about their lack of recall and uncertainty over some. Their answers were often qualified with ‘I don’t recall’, ‘I think so’, ‘perhaps, ‘maybe’ and ‘I can’t recall, no’. Too often, when a contradictory version of events was put to a witness, the witness qualified their earlier evidence and expressed uncertainty over their precise recollections. 25 Generally, no serious criticism of poor recollections as to the order of events or matters of detail should be made and the relevant documentary evidence is to be preferred for dates and detail in preference to inexact and faded recollections. 26 There were some matters of importance where the evidence of the various witnesses was unsatisfactory in some respects and warranted specific comment. For convenience, those comments are made in the context of the relevant topic having regard to the issues in contention. The Witnesses Called Mr Apostolakos 27 Contek’s only witness was its founder and principal, Mr Paul Apostolakos. Mr Apostolakos was the only witness in the case who gave lengthy evidence. He was extensively cross-examined, and his credit challenged by Mossop on a number of issues. Mossop submits his evidence should not be accepted on any topic where it is contentious. 28 Overall, Mossop’s criticisms are overstated. Whilst it may be accepted there were occasions Mr Apostolakos was prone to exaggerate (such as the water ‘cascading’ into the basement), that does not undermine all of his evidence. Further, Mossop’s submissions to the effect that it was Mr Apostolakos’ position that ‘everyone else is to blame’ are beside the point and at most reflect his frustration about the dispute over Contek’s variation claims that were stone-walled and then met with a series of back charges and lengthy litigation. 29 The same criticisms made of Contek’s lack of paperwork could also be made of Mossop’s project management team. Any such criticism should be disregarded. It must be acknowledged that whilst both parties were commercial contractors, both are builders, not lawyers, and were plainly focussed on the works required to be done and maintaining a working relationship. As the documentary evidence shows, emails were short, direct and sent infrequently. There was much informality about on-site communications, as is often the case on busy construction sites. -- 11 of 106 -- [2024] SADC 1 10 30 As regards the extra concrete variation claims, Contek’s first claim for the ground floor (V2) was made within four weeks of completing the pour. In the circumstances where the works involved the change in the concrete mix and regular interactions on site, it is not surprising that there were no contemporaneous written complaints preceding the first concrete variation. The second and third concrete variation claims were made in May 2017 before any extensive correspondence between the parties about these claims and other outstanding variation claims. Mossop’s criticism about Contek’s lack of written complaint is therefore unpersuasive. 31 Mossop’s criticism about Contek’s take-off documents should also be disregarded. The criticism is not relevant to any issue. They were not in evidence because Mossop (reasonably) objected to them being tendered when they were produced at trial for the first time, not having been discovered. What was relevant was the reasonableness of the volume of standard concrete mix allowed as a credit, an essential component in the calculation of Contek’s variation claims for extra concrete. 32 Even so, given the importance of the issues to the parties, Mr Apostolakos’ evidence has been critically reviewed where it is contentious. Observations relevant to the issues to be determined have been made later in these reasons in the context of the relevant topics. Mr Stringer 33 Mr Travis Stringer was Mossop’s site manager for the Lifecare Project. His employment began in late January or early February 2017 after the ground floor slab was poured. His evidence was relevant to two topics: first, the dispute over his alleged on-site oral direction to raise the finished floor levels on the first and second floors and, secondly, directing Contek to persist with the last pour of the basement in bad weather. 34 Mossop described Mr Stringer as plain speaking and credible. Contek described him as a poor and unreliable witness. Overall, he was not an impressive witness. Mr Stringer generally lacked recall and was uncertain of many matters that occurred long ago, qualifying much of his evidence as such. On the topic of the on-site direction to vary the finished floor levels, Contek’s criticism about his evidence should be accepted for the reasons discussed below in the context of this topic. However, Contek’s criticisms of his lack of recall of the design changes to the basement are overstated and should be disregarded. Mr Orlovic 35 Mr Harry Orlovic was Mossop’s Project Manager and the named Subcontract Superintendent for the Lifecare Project.18 Despite his central role in the Lifecare 18 Exhibit A1 page 183, Part A – Subcontract Particulars. -- 12 of 106 -- [2024] SADC 1 11 Project his evidence and cross-examination were relatively short. Both parties submit his evidence should be accepted as reliable. 36 However, some aspects of Mr Orlovic’s evidence were questionable when viewed objectively in the context of the wider evidence, particularly on the topic of the on-site direction to vary the finished floor levels. As with Mr Stringer, the reasons for finding some of his evidence unsatisfactory are discussed below in the context of the relevant issues. Mr Mossop 37 Mr Neil Mossop is the managing director of Mossop with decades of experience in the construction industry. 38 Late in the interlocutory stages between the first and second parts of trial, an application was pressed to call Mr Mossop as an expert witness without having complied with the rules as to a written expert’s report.19 The application was opposed by Contek. Out of fairness, the Court ruled that Mr Mossop would not be permitted to give opinion evidence on matters calling for the special skill and knowledge of an expert witness. He was, of course, permitted to give evidence on matters observed relevant to the issues in dispute. 39 Mr Mossop was not therefore called as a testifying expert witness. His lay evidence was of limited scope and assistance in determining the relevant issues because of his limited involvement in relevant matters. Mr Mossop was not on site during any of the concrete pours for either project. Mr Mossop’s role primarily concerned the commercial decisions made to approve or reject the contentious variation claims made by Contek, despite the contractual obligations of the Subcontract Superintendent to assess variation claims fairly and reasonably. Mr Mossop authored the narratives and closely supervised the ensuing litigation. 40 To the limited extent Mr Mossop’s evidence is relevant to the issues in dispute, and subject to the Court’s ruling, it is to be accepted as reliable. As already stated, the narratives are submission, not evidence, and have been treated accordingly. Mr Lalli 41 Mr Lalli is employed by Mossop as a contract administrator. He joined Mossop in a site administration role on the Lifecare Project in July 2017 after all floor levels were poured, the structure was up and fit-out was in progress. 19 Interlocutory Application (FDN 77) supported by Affidavit of Nicholas John Anderson made 5 August 2022 (FDN 78). -- 13 of 106 -- [2024] SADC 1 12 42 Mr Lalli was instructed by his manager, Mr Tziortzis, to take measurements of the distance between the top of the slab and the bottom of the set-downs for the bathroom pods on the first and second floors. He recorded his measurements on slab plans. 43 Mr Lalli should be accepted as a witness of truth and Contek does not submit otherwise. Mr McFarlane 44 Mr John McFarlane is a licensed surveyor and principal of Alexander Symonds. Mr McFarlane’s expertise is not challenged. Contek’s complaint about his lack of independence given Alexander Symonds’s pre-existing commercial relationship with Mossop is unpersuasive and should be disregarded. 45 Mr McFarlane gave detailed and considered evidence. He was frank about the limitations of the survey evidence and the derived floor and slab thicknesses. 46 Mr McFarlane’s evidence should be accepted unreservedly. Witnesses Not Called Mr Kemp 47 Mr Kemp was Contek’s foreman and Mr Apostolakos’ right hand for the Lifecare Project. He was involved in the on-site discussions about the varying levels of the Deltacore floor panels and the basement pour in bad weather. Given the way the evidence fell from the other witnesses, it should be accepted that Mr Kemp’s evidence would have elucidated relevant matters. His absence as a witness has been taken into account as not assisting Contek’s case in determining relevant matters where appropriate. Mr Barone 48 Mr Joe Barone was as estimator employed by Mossop and named as its contact for the concrete works tenders for the Lifecare Project. Mr Barone had carriage of negotiations with Mr Apostolakos in late September 2016 over a revised subcontract price for a revised scope of works during a formal tender process. 49 Mr Barone’s evidence was most relevant to Contek’s rectification claim. In his absence, it should be inferred that Mr Barone’s evidence on the topic would not have added anything to the matters clearly expressed in the relevant email correspondence. Mr Zilic 50 Mr Tomi Zilic was a contract administrator employed by Mossop for the early stages of the Lifecare Project. His involvement was largely documented and only of relevance to Contek’s rectification claim. It should be also inferred in his -- 14 of 106 -- [2024] SADC 1 13 absence that Mr Zilic’s evidence on this topic would not have added anything to the matters clearly expressed in the relevant email correspondence. Mr Tziortzis 51 Mr Kosti Tziortzis was employed by Mossop during the Lifecare Project. 52 Mr Tziortzis’ absence as a witness calls for comment on one issue. He was the author of an email sent to Mr Apostolakos on 22 August 2017 attaching site plans recording the measurements taken by Mr Lalli. In this email he referred to a telephone conversation with Mr Apostolakos on the previous day during the course of which Mossop alleges certain things were agreed, including as to the costs of retaining Alexander Symonds to conduct a survey of the thickness of the topping slabs. 53 In circumstances where the parties were in dispute and in the absence of an opportunity to test his evidence, his email referring to an agreement reached on the telephone should be given no weight. PART D: LIFECARE PROJECT – TOPIC 3 - EXTRA CONCRETE The Dispute – $58,008.38 ex GST20 The Variation Claims 54 Contek made three variation claims (V2, V6 and V8) for additional concrete used in the topping slabs (concrete variation claims). 55 The original subcontract scope of works required 60mm21 mesh reinforced concrete topping slabs to be laid over precast concrete ‘Deltacore’ panels that were to be installed by another subcontractor under Mossop’s supervision. Structural design changes were made to the concrete mix and reinforcing to be used in the 60mm topping slab and it is uncontentious these changes were valid variations to the subcontract scope of works and adjustments to the subcontract sum. 56 V222 concerns the ground floor topping slab that was poured between 20 and 30 January 2017. The claim is dated 25 February 2017 and described as: DETAILS: Variation – Steel Fibres to Ground Floor Topping Slab in Lieu of Mesh & Additional Concrete Used Due to Discrepancies in Deltacore Floor23 57 V2 claims 241.7 cubic metres @ $301/cubic metre for a Helix fibre concrete mix (Helix mix) less credits for 148 cubic metres @ $162/cubic metre for a standard 32 MPa concrete mix (standard mix), the supply of mesh reinforcement 20 $63,809.22 inc GST. 21 There were some set-downs where the specified topping thickness was 160mm or 400mm. 22 Exhibit A3.1 page 145. 23 Emphasis supplied. -- 15 of 106 -- [2024] SADC 1 14 (8.3 tonnes) and labour to fix the mesh reinforcement. It also includes minor claims for additional concrete testing and pumping, a 5% administration fee and GST. 58 V624 concerns the first floor topping slab that was poured on 28 March 2017. The claim is dated 17 May 2017 and described similarly, referring to additional concrete being used due to discrepancies in the Deltacore flooring. V6 claims 183.4 cubic metres @ $301/cubic metre for a Helix mix less credits for 111.24 cubic metres @ $162/cubic metre for a standard mix, the supply of mesh reinforcement (6.27 tonnes) and labour to fix the mesh reinforcement. It also includes minor claims for additional concrete testing and pumping, a 5% administration fee and GST. 59 V825 concerns the second floor topping slab that was poured on 5 May 2017. The claims is also dated 17 May 2017 but is described as: DETAILS: Variation – Steel Fibres to Second Floor Topping Slab in Lieu of Mesh 60 V8 claims 143.5 cubic metres @ $301/cubic metre for a Helix mix less credits for 92.22 cubic metres @ $162/cubic metre for a standard mix, the supply of mesh reinforcement (5.6 tonnes) and labour to fix the mesh reinforcement. It also includes minor claims for additional concrete testing and pumping, a 5% administration fee and GST. 61 Ultimately, on 30 May 2018, after an interim assessment made in September 2017 and much dispute by correspondence, Mossop issued variation orders26 approving Contek’s claims for an increased price ($139 more per cubic metre) for the more expensive Helix mix but for only some 20% of the additional volume of concrete claimed and for only the first and second floors. No additional volume was allowed for the ground floor. Mossop calculated the approved volumes on the basis of estimates of the average slab thickness for each floor derived from a survey of the AsBuilt floor thicknesses by licensed surveyor Mr John McFarlane of Alexander Symonds27 and a measure undertaken by the project quantity surveyors, WT Partnership.28 Claimed Additional Volumes 62 The parties’ dispute therefore concerns only one component of Contek’s concrete variation claims: the claimed extra volume of Helix mix. The following table sets out each variation claim and Contek’s calculation of the additional volumes in cubic metres. 24 Exhibit A3.1 page 147. 25 Exhibit A3.1 page 149. 26 Exhibit A3.1 pages 260-67. The credits allowed for mesh reinforcement and labour omitted from the subcontract scope of works by reason of the change in concrete mix were also approved. 27 Exhibit A3.1 pages 261, 245 and 252 for the ground, first and second floors respectively. 28 See [198]-[205] below. -- 16 of 106 -- [2024] SADC 1 15 Table 3 No. Description Actual Supplied (m3) Less Original Allowance (m3) Additional Claimed (m3) V2 Extra Concrete – Ground Floor 241.7 148 93.7 V6 Extra Concrete – First Floor 183.4 111.24 72.16 V8 Extra Concrete – Second Floor 143.5 92.22 51.28 Total 568.6 351.46 217.14 63 There is no substantive basis for disputing the actual supplied volume of Helix mix for the topping slabs as proven by the Hanson delivery dockets. Mossop’s counsel properly conceded the issue in the second part of the trial.29 The Hanson delivery dockets30 prove supply of 550.3m3, that is 18.3m3 less than the total claimed by Contek as shown in the first column of Table 3 above. Contek’s claim should be reduced accordingly. 64 Mossop submits ‘returns’ and ‘cancelled but charged’ volumes were incorrectly claimed by Contek.31 As to ‘returns’, they are charged and properly claimable and should be factored in as waste in any event since unused concrete is not usable on return.32 In the absence of any specific evidence about the cancelled and invoiced delivery, it should be also considered as waste and is properly claimable. 65 The volumes shown in the second column of Table 3 above are the subject of dispute as to the adequacy of Contek’s original allowance for concrete for the topping slabs as specified in the contract drawings. This is ‘Issue 4’ considered below.33 66 Table 4 below sets out for each variation claim the additional volumes claimed, those allowed on assessment and paid with the difference being the volumes in dispute. 29 T23.11-.13. 30 Exhibit R17 pages 578 to 707. See also Exhibit A14 which overstates the volume of Helix mix supplied by 6.1m3. 31 Written Submissions of the Respondent [110]. 32 Mossop conceded as much in its Written Submissions of the Respondent [126.4]. 33 See [290]-[327] below. -- 17 of 106 -- [2024] SADC 1 16 Table 4 No. Description Additional Claimed (m3) Assessed & Paid (m3) Disputed (m3) V2 Extra Concrete – Ground Floor 93.7 0 93.7 V6 Extra Concrete – First Floor 72.16 32.65 39.51 V8 Extra Concrete – Second Floor 51.28 12.7 38.58 Total 217.14 45.35 171.79 67 Table 5 below sets out for each variation claim, the total value claimed, the final approved value and adjustment to the subcontract sum and the disputed value. Table 5 No. Description Claimed Value ex GST Approved Value ex GST Disputed Value ex GST V2 Extra Concrete – Ground Floor34 $36,217.97 $4,977.00 $31,240.96 V6 Extra Concrete – First Floor35 $26,973.24 $13,250.59 $13,722.65 V8 Extra Concrete – Second Floor36 $18,590.52 $5,545.76 $13,044.77 Total $81,781.73 $23,773.35 $58,008.38 The Parties’ Contentions The Pleadings 68 Contek pleads the subcontract works were varied by a change to the concrete mix design and additional concrete was required to be supplied to raise the finished levels of the topping slabs “due to significant voids and inconsistencies in the Deltacore floor”.37 No detail is pleaded as to the nature of the “significant voids and inconsistencies” except by inference from allegations pleaded in its reply as to the consequential raising of the floor levels and reference to photographs of the ‘inconsistent’ Deltacore panels sent to Mossop. 69 Mossop admits the subcontract specification was changed to a Helix mix and the reinforcing mesh deleted38 from the topping slabs but denies there were voids and inconsistencies in the Deltacore floor other than those to be expected and known to Contek.39 This plea should be understood as referring to such voids and 34 Exhibit A3.1 page 261. 35 Exhibit A3.1 page 245. 36 Exhibit A3.1 page 252. 37 Claim [6.1], [6.3] and [6.5]. 38 Defence [6.1.1.2]. 39 Defence [6.1.2.1]. -- 18 of 106 -- [2024] SADC 1 17 inconsistencies as specified in the original scope of works as shown by the contract drawings. 70 Mossop’s pleaded denial of any significant voids or inconsistencies in the Deltacore floor other than those known or expected was never sustainable on the evidence as acknowledged by its own assessment that some additional concrete was required. Mossop’s own survey results indicate a significant degree of variability in slab thickness and by implication the evenness of the underlying Deltacore floor, on the reasonable assumption that the finished tops of the slabs were flat. 71 In opening Mossop’s case, its counsel conceded that the finished floor level was raised for part of the second floor, and by implication that the Deltacore floor in at least that area was excessively cambered. Unsurprisingly given the course of the evidence, by the close of trial Mossop’s case had shifted to the Deltacore floor not being “proved to be nearly as uneven” as Mr Apostolakos asserted in his evidence.40 72 The real dispute about this issue is therefore the extent to which the Deltacore floor panels were uneven and in what other respects there were unexpected ‘inconsistencies’ (if any) requiring additional concrete and an adjustment to the subcontract sum. 73 As to contractual entitlement in answer to the allegations concerning extra concrete, Mossop pleads in the most general of terms that Contek did not comply with “the contract pertaining to notification of variations but… in any event says that instead any extra concrete… has been resolved and paid…”.41 74 No supporting material facts or particulars of the relevant contractual provisions are pleaded. 75 Mossop further alleges that it was agreed that Mossop would pay for the volume of additional concrete used according to the results of the Alexander Symonds survey and the parties would share the costs of the survey. Mossop denies liability for any further amount by reason that, as allegedly agreed, it has paid Contek for additional concrete on the basis of the calculation of average slab thickness derived from the survey results. 76 Mossop puts in issue the required and actual volumes used, relying on estimates of the topping slab concrete (including “the gaps between the panels and infills”42 based on the Deltacore drawings) made by quantity surveyors WT Partnership. Mossop denies any significant change between drawings, alleging a reduction in the concrete actually required. 40 Written Submissions of the Respondent [93]. 41 Defence [6.1.2.2] and [6.1.2.3]. 42 Defence [6.1.10]. -- 19 of 106 -- [2024] SADC 1 18 77 In reply, Contek pleads that by reason of “the inconsistencies” in the Deltacore floor, the concrete levels were raised on site at the direction of Mr Travis Stringer,43 up to 60mm in some areas44 and 60mm from the highest point,45 and denies any agreement binding it to the results of the Alexander Symonds survey. 78 Contek pleads in the alternative to its contractual claim for damages, a restitutionary claim for quantum meruit. This claim was not addressed by either party at trial, save a passing reference made in closing by Contek’s counsel to the relevant pleading. It is neither necessary nor appropriate to consider this claim in circumstances where Contek has enforceable contractual rights to recover damages or moneys due under the subcontract that are inconsistent with a restitutionary remedy.46 The Parties’ Contentions at Trial 79 The focus of Contek’s case at trial was the appropriate measure for the volume of additional concrete used to value Contek’s concrete variation claims. Subsidiary but important factual disputes concerned the verbal on-site direction allegedly given by Mossop’s Site Manager, Mr Stringer, to raise the finished floor levels and the extent of the inconsistencies in the Deltacore floor panels and requirement for additional concrete as alleged or otherwise. 80 Contek’s pleaded case gave no regard to the subcontract terms entitling an adjustment to the subcontract price by reason of a variation to the scope of works for the additional volume of concrete claimed. Contek submits the dispute the Court is required to determine is confined to the extent to which Contek should be paid for the increased volume of concrete mix based on the volume actually supplied less its tender allowance based on the original scope of topping slab concrete works as shown in the tender drawings. 81 To illustrate the conceptual problem to be resolved by the Court, Contek used the analogy of pouring water into a bucket filled with stones to describe pouring the topping slabs on top of the inconsistent Deltacore floor. It submits the best way to measure the additional amount of concrete (or water) poured into the topping slabs (or bucket) is to measure the actual amount poured and deduct the tender allowance. 82 This was referred to by the parties variously as the ‘bucket theory’ or ‘bucket method’ of measuring the extra concrete claimed. 83 Mossop submits the ‘bucket theory’ advanced by Contek is flawed and unproven because it disagrees that the issues to be determined are confined to just the actual volume of concrete delivered to site and, consistent with Mossop’s pleaded defence, challenges Contek’s claimed entitlement to an adjustment of the 43 Reply [2.2] and [7]. 44 Reply [3.2]. 45 Reply [7.2]. 46 Mann v Paterson Constructions Pty Ltd (2019) 267 CLR 560. -- 20 of 106 -- [2024] SADC 1 19 subcontract sum for additional concrete on a number of broader bases, generally criticising Contek’s case as implausible, illogical and unproven. 84 The grounds of defence presented at trial by Mossop were numerous. First, (despite the formal approval of some of Contek’s claim for an additional volume of concrete and adjustment of the subcontract sum) it contends there was no direction or instruction from Mossop for additional concrete topping as pleaded by Contek or otherwise. Secondly, the claims are contract barred because Contek did not comply with its obligations under clause 24.2 of the subcontract to give a notice of variation. 47 Thirdly, Contek has not proved that an additional 60mm of concrete was added to the topping slabs in circumstances where Mossop has reliably proved the average slab thickness was less than claimed. Fourthly, there are other explanations as to where the additional concrete went that are as expected (including that Contek underestimated the volume of concrete required) and therefore not to Mossop’s account. Fifthly, Mossop has paid for the additional concrete as agreed would be quantified by the Alexander Symonds survey. Sixthly, there is no claim for ‘voids’. The Issues to be Determined The Ultimate Question 85 Properly framed, the ultimate question to be determined by the Court is how much of the disputed claimed additional concrete is extra to the subcontract scope of works and constitutes a variation entitling Contek to a further adjustment to the subcontract sum. Contek’s claim is therefore not confined to slab thickness as Mossop contends. Nor is the question simply one of the preferred valuation method as Contek submits, that is, determination of the method that most reliably quantifies the additional volume of concrete supplied. 86 It is not necessary to address the ‘bucket theory’ further. Not Just Slab Thickness 87 Mossop’s first contention is that gaps between the Deltacore panels (joints) and voids (infills) in them are not the subject of Contek’s concrete variation claims.48 That is not correct. Discrepancies in the nature of gaps and voids are plainly the subject of these variation claims, just as are the varying levels of the underlying Deltacore floor. These claims were generally described as being “due to discrepancies in the Deltacore floor” and extra concrete required for gaps and voids is necessarily included by calculating the claim by reference to the volume of Helix mix delivered to site by Contek’s supplier, Hanson. The concrete delivered to site was used to pour the topping slabs over Deltacore floor panels of varying heights laid with gaps between the panels (joints) and voids (infills) and fillings to cored Deltacore panels as specified in the drawings. 47 Written Submissions of the Respondent [48]-[52]. 48 T124.33-.36; T125.4-.7. -- 21 of 106 -- [2024] SADC 1 20 88 Plainly, the Court is only required to determine an issue to the extent it is raised on the pleadings and the parties are, as a general rule, confined to the pleaded causes of action and defences agitated at trial. Where an unpleaded claim is agitated at trial and a party has adequate notice of the case it has to meet generally, it will not generally matter that findings are made and judgment is given on unpleaded claims.49 89 Contek pleads that additional concrete was required to raise the finished floor level due to significant ‘voids’ and ‘inconsistencies’ in the Deltacore floor.50 As already emphasised, the nature of such ‘voids’ and ‘inconsistencies’ was not detailed or explained further in Contek’s pleadings, save for reference in its reply to photographs showing the ‘inconsistent’ Deltacore panels51 and references to an on-site instruction to raise floor levels (i.e. slab thickness).52 90 Mossop did not complain about the generality of Contek’s pleaded case before trial. Before proceedings were instituted, Contek’s claims were the subject of a protracted assessment process under the subcontract and extensive correspondence. It should therefore be inferred that the parties well knew the issues in dispute. Mossop’s first objection about a claim for ‘gaps’ was late and made part-way through the second part of the trial despite Contek’s counsel having opened Contek’s concrete variation case twice (10 months apart) on there being extensive ‘gaps’ and ‘voids’ in between Deltacore floor panels of varying heights and after evidence had been received on this topic in both parts of the trial.53 Whilst Mossop concedes this evidence is relevant contextually, it contends Contek has confined its concrete claims to the pleaded ‘voids’ and ‘inconsistencies’ that raise the finished floor level so that the only claim it must meet concerns only slab thickness. That is, there is no pleaded case of ‘gaps’ between panels (joints) or ‘voids’ that Mossop must meet.54 91 Yet Mossop joined issue in its pleaded defence as to whether there were significant ‘voids’ and ‘inconsistencies’ in the Deltacore floor. It did so by first denying there were any other than those expected and known to Contek55 and secondly by alleging that “gaps between the panels and infills based on the Deltacore drawings” were required to have been included in Contek’s tender allowance.56 Accordingly, Mossop put in issue the contribution of all ‘voids’ and ‘inconsistencies’ in the Deltacore floor to the usage of additional concrete by alleging there were not any that were compensable. 49 NRM Corporation Pty Ltd v ACCC [2016] FCAFC 98 at [26]. 50 Defence [6.1.2]; Reply [2], [3] and [7]. 51 Reply [2.1]. 52 Reply [2.2], [3.2], [7.1] and [7.2]. 53 T125-157. 54 T143.24-.29. 55 Defence [6.1.2]. 56 Defence [6.1.10]. -- 22 of 106 -- [2024] SADC 1 21 92 Any suggestion that Mossop did not know it had to meet the case Contek presented at trial and was caught by surprise is uncompelling and should be rejected. During the works, Contek complained at an early stage about the extent of ‘voids’ and ‘gaps’ in the Deltacore floor on the ground floor and then again, when preparing to pour the first floor, Mr Orlovic, Mossop’s Project Manager and Subcontract Superintendent, instructed that they were “unavoidable” and needed to be blocked up.57 From the outset, Contek claimed additional concrete by reference to all the concrete supplied less its tender allowance, thereby claiming the volume poured into the topping slabs and into the gaps between the panels (joints) and voids (infills and fillings of cored panels) as the drawings specified. 93 During the assessment process, Mossop rejected these claims on numerous grounds including where else the concrete might have gone such as the ‘voids’ and ‘gaps’ that were expected and known to Contek. 94 In any event, Mossop has met at trial the claim for ‘gaps’ it objects to as not being pleaded. It has done so by way of extensive written submissions that expressly address ‘gaps’ between the panels (joints), ‘voids’ (infills and fillings of cored panels) and varying levels in the Deltacore and whether they are compensable as a variation to the subcontract scope of works,58 without adducing any expert evidence on the topic. Not Just a Valuation Question 95 The ultimate question to be determined is also not just a question of valuation as Contek submits. 96 The starting point is Contek’s contractual entitlement to claim a variation and adjustment to the subcontract sum in the circumstances found to the extent contractual entitlement is an issue raised on the pleadings. 97 This qualification is important because only one issue of contractual non- compliance was pleaded by Mossop as regards Contek’s concrete variation claims. That is Mossop’s previously mentioned defence of Contek’s alleged non- compliance with contractual notices for variation. The relevant provisions are obvious from reading the subcontract conditions, although none are expressly pleaded. As Mossop’s counsel put it, “it’s impossible to think that a competent counsel” did not know or understand the relevant subcontract clauses.59 The same may be said for both parties and should be borne in mind in considering the limited scope of Mossop’s pleaded defence of contractual non-compliance and is not a basis for extending the grounds of defence to include unpleaded contractual defences. 57 Exhibit A3.3 pages 813-14. 58 Written Submissions of the Respondent [65] to [129]. 59 T799.19-22. -- 23 of 106 -- [2024] SADC 1 22 98 The valuation question involves consideration of a number of controversial factual issues of some complexity. First, what was the nature and extent of unexpected and unknown ‘inconsistencies’ in the Deltacore floor? Secondly, how (if at all) did any such inconsistencies result in a requirement for additional concrete, including whether any on-site directions were given to increase the finished floor levels? 99 This issue of what was additionally required is multifaceted. It requires an analysis of why more concrete was used or, as Mossop colloquially described it: ‘where did the concrete go?’ Mossop contends it has not just gone into thicker topping slabs to the extent claimed and relies on measurements taken of the slab thickness in the bathroom set-downs and the Alexander Symonds survey and calculations of average slab thickness to prove its case. 100 The adequacy of Contek’s ‘tender’ allowance is disputed. If it was inadequate, as Mossop ultimately contends, it follows more concrete should have been used than estimated and is not additional and a variation to the subcontract scope of works. The Issues to be Determined 101 The Court has approached resolution of the parties’ dispute over the concrete variation claims by first considering evidence of topics that are foundational to the key issues. 102 The survey evidence is particularly important for two reasons. First, there is the highly contentious question as to what reliance can reasonably be placed on these results to determine the validity of the claimed additional concrete volumes. The second reason is more basic. Despite their limitations, these survey results are the best evidence of significant variability in the thickness of the topping slabs due to variation in the levels of the underlying Deltacore floor panels. The survey results support the other evidence as to vertical ‘discrepancies’ and ‘inconsistencies’ in the Deltacore floor. Plainly, they shed no light on horizontal ‘discrepancies’ and ‘inconsistencies’ in the Deltacore floor. 103 On this foundation, the following key issues to be determined are considered and answered. 1. Was there an instruction or direction constituting a variation? 2. Are these variation claims contractually barred? 3. Is the Alexander Symonds survey result binding? 4. Was Contek’s standard concrete allowance adequate? 5. What is a fair and reasonable measure for any additional concrete? -- 24 of 106 -- [2024] SADC 1 23 The Evidence The Topping Slab Works 104 To properly appreciate the significance of the technical evidence it is necessary to consider the specified scope of works, the method for pouring the topping slabs and the areas involved. 105 Contek’s scope of works included installing the formwork for and pouring of topping slabs over Deltacore precast concrete floor panels on the ground, first and second floors of the building being constructed by Mossop. 106 The precast panels come in various lengths, are 1197mm wide and 205mm deep.60 The panels are formed with core holes (where they are extruded) and are fitted with tensioning reinforcing rods top and bottom that run the length of the panel. The tensioning rods cause the panels to be cambered (curved) along the length of the panel. The high point of the camber was referred to in the evidence as the ‘hog’. The camber in the panels is expected to settle under load from the concrete topping slab. 107 The floors on the first and second levels of the building were formed by laying individual Deltacore panels on suspended structural steel frames in two directions and pushing them together. The ground floor was similarly formed by laying Deltacore floor in two directions on structural steel but between two raft slabs (poured separately in a different concrete mix). 108 Concrete was then poured on top of the Deltacore floor panels to form the concrete topping slab61 that covers the Deltacore panels and fills the gaps between the panels (joints) and any specified voids (infills) in the panels or between the panels and structural steel or precast walls and fills specified cored sections of panels (fillings) where reinforcing bars were to be screwed in. 109 On the first and second floors two edge beams (one 400mm thick the other 175mm thick) surrounded the topping slabs and were poured with a different mix of concrete. 110 The Deltacore marking plans62 specified the layout of the panels and the joints and infills to be filled with topping slab concrete. The structural slab plans showed the areas where the Deltacore floor panels were to be laid within the 400mm and 175mm edge beams. The Deltacore floor was not to be laid where there were voids for lifts and stairwells or in the set-downs for prefabricated bathroom pods in the bedrooms on each floor. 60 Deltacore floor panel drawings Exhibit A3.1 pages 140 and 142. 61 Deltacore marking plans Exhibit A3.1 pages 139, 141 and 143. 62 Exhibit A3.1 pages 139, 141 and 143. -- 25 of 106 -- [2024] SADC 1 24 111 The Deltacore panels were rebated and chamfered at the top so the joint between adjacent panels was wider at the top than at the bottom. The standard width of the rebate at the bottom of the chamfer is 21.5mm. The chamfer on each is 15mm. Gaps between the bottom of the panels were specified on the marking plans to be 3mm. Therefore, the expected width of the joint between panels laid 3mm apart at the bottom of the chamfer was 46mm and at the top of the chamfer, 76mm.63 112 Connections and other details (such as where the break outs of the top of panels were to be cored for balcony reinforcing to be screwed in and then filled with topping slab concrete)64 were shown on the structural drawings. 113 The boards used to form the topping slabs were 95mm high. This benchmark was referred to in the evidence to assist in appreciating heights and widths in photographs of the works during construction. 114 The standard mix was to be reinforced with SL72 fabric (reinforcing mesh) throughout. In January 2017, the standard mix was changed to a Helix mix and the reinforcing mesh was omitted. 115 The usual method for pouring and setting the finished level of the topping slabs was uncontentious. Before pouring the concrete, Contek was required to undertake various preparatory works such as installing formwork for the different pours, the bathroom set-downs (pods) and edges (such as on top of precast walls and around lift and stairwells). It was also required to core or break out sections of the Deltacore panels and screw in reinforcing bars as well as blocking up areas to stop concrete bleeding through cracks and gaps. 116 Mossop contracted a surveyor to set the finished floor level for each topping slab by marking a post with a datum as Contek’s reference point in setting the finished levels of the concrete it was to supply, pump and place. Before pouring Contek would ‘check the levels’ by putting a laser level across the floor. Mr Apostolakos explained in evidence this involved him and his site supervisor, Mr Kemp, walking around the floor using a staff and tripod with a laser light to check that the datum set by Mossop’s surveyor met the required cover, that is, a slab thickness of 60mm. It was during this process that Mr Apostolakos and Mr Kemp identified significant variation in the height of the Deltacore floor panels affecting the amount of cover that could be achieved by a 60mm topping slab in many places. 117 Based on Contek’s ‘Bluebeam’ take-offs, the areas of the topping slabs and corresponding volumes for a 60mm thick slab (not allowing for wastage, joints, 63 That is 21.5mm x 2 + 3mm + 15mm x 2. See Deltacore floor panel drawings referred to above. 64 For example, drawing S23:00 Sections 21 and W. Exhibit A3.1 page 15b. -- 26 of 106 -- [2024] SADC 1 25 gaps or voids, the bathroom set-downs or 160mm thick slabs) were as follows.65 Table 6 Floor Ground First Second Total Area (m2) 2,525.73 1,869.59 1,552.46 5,947.78 Less Voids (m2) 61.47 15.56 15.54 92.57 Net Area (m2) 2,464.26 1,854.03 1,536.92 5,855.21 Net Volume (m3) 147.86 111.24 92.22 351.32 118 These were the net areas and volumes used in Contek’s concrete variation claims for additional concrete required by reason of unspecified ‘discrepancies’ in the Deltacore floor panels. The volumes are simply calculated as the area x 60mm. 119 Whilst the required volumes are challenged, the areas ultimately were not, and the same or nearly same areas (depending on the floor) were used by Mossop in its final assessment.66 Mossop’s Assessment 120 The documentary evidence of Mossop’s initial assessment of the concrete variation claims is the best contemporaneous evidence of the real issues in dispute. This evidence gives important context to the witnesses’ oral evidence about events that by the time of trial were distant, accepting that it was difficult for all of the witnesses to reliably recall what had happened so long ago. 121 Contek submitted variation claim V2 with its 25 February 2017 payment claim within a month of completing the pour of the ground floor. Mossop’s Contract Administrator, Mr Zilic, reviewed the claim. On 22 March 2017, Mr Zilic sent Mr Apostolakos an email (copied to Mr Orlovic and Mr Stringer) querying the prices in V2. He asked Mr Apostolakos how he “got to the /cube rates” and for a full breakdown of costs.67 122 Later the same day, Mr Zilic sent Mr Apostolakos a second email (also copied to Mr Orlovic and Mr Stringer) further commenting on V2. He said Mossop expected a net credit and not increased cost from the change in the design of the standard mix to a simpler, less labour-intensive and cheaper solution. His email focussed again on price not quantity. The credit for the standard mix was said to 65 Calculated by Mr Apostolakos using Bluebeam software. Exhibit A3.1 pages 158-60 and pages 173-75 in colour. 66 The same area was used for ground floor, and the differences for the first and second floors was immaterial. See Exhibit A3.1 pages 261, 245 and 252 for the ground, first and second floors respectively; T196.18-.21. 67 Exhibit A3.1 page 282. -- 27 of 106 -- [2024] SADC 1 26 be “light on” because Contek had charged a higher price for a previous variation claim.68 No complaint was made about the additional volumes claimed. 123 During May and June 2017, Mr Apostolakos asked Mr Zilic multiple times for a response to his email in relation to V2,69 without any substantive response. Meanwhile, Contek submitted claims V6 and V8 on about 17 May 2017. 124 On 14 July 2017 Mr Apostolakos sent by email ‘revised’ variations claims V2, V6 and V8 to Mossop for assessment, together with calculations to substantiate the volume of concrete allowed in Contek’s tender and photographs of the inconsistencies in the Deltacore flooring.70 The claims were not revised, rather this time accompanied by substantiating material. Contek’s claims led to an immediate exchange of emails between the Mossop representatives and Mr Apostolakos. 125 Mr Orlovic responded first, stating that he would let Mr Zilic deal with the claim, however:71 …(steel fibre) concrete supplied should match the credit concrete. i.e. 148 cubic metres on ground floor credited against 148 steel fibre concrete. Why do you have it at 241.7m2? which is 93m2 more? It wasn’t used for the perimeter in-situ sections. All other perimeter concrete was normal concrete and always allowed for. No additional testing will be paid. No additional pumping will be paid. This brings it down to $4,340 plus admin. For ground floor. 126 It is telling that Mr Orlovic only complained about the increased volumes for the ground floor. His lack of complaint about the first and second floors is explained in an email sent later that day. 127 Mr Apostolakos replied immediately by email72 confirming that the only areas used in Contek’s take-off were the topping slabs and that so much more concrete was used than allowed as per the plan because the finished concrete levels on site were raised to accommodate the inconsistencies in the flooring. He said:73 Harry the levels were raised to such an extent that we had to provide a 30mm rebate to levels 1 & 2 to the slab perimeter for the windows to work in height because they were already made (Travis gave me this instruction on the day of the pour). 68 Exhibit A3.1 page 281. 69 Exhibit A3.1 pages 275-80. 70 Exhibit A3.1 pages 151-166, 285. 71 Exhibit A3.1 page 287. 72 Exhibit A3.1 page 287. 73 Exhibit A3.1 page 286. -- 28 of 106 -- [2024] SADC 1 27 128 Mr Apostolakos then asked why if additional concrete was used due to the levels being raised, the additional pumping and concrete testing would not be paid. He suggested they may need to meet to review the information. 129 Mr Orlovic responded, agreeing they may need to meet, saying:74 The only floor raised was level 1, by 20mm or so. You can check the RL’s, but RL’s are as per plan except level 1. Also due to the camber in the deltacore the thickness is less than 60mm in the middle section of delta, whereas on the ends it may be more so it evens out. You cannot claim an extra 90m3 over that area. 130 Some important observations should be made about this email. First, it explains why Mr Orlovic’s complaint focussed on the volumes for the ground floor when it is appreciated that Mr Orlovic was referring to the raising of the height of the finished floor level relative to the datum point fixed by Mossop’s surveyor. Secondly, Mr Orlovic’s last statement was only correct if the engineer’s specification for slab thickness was not met. The specified cover was a minimum 60mm, so any camber in the middle of a Deltacore floor panel required additional depth of cover at the lower ends. 131 Mr Apostolakos replied,75 stating the levels were raised to the extent that Contek had to provide a 30mm rebate to levels 1 and 2 slabs for the ready-made windows to fit. For the second time he referred to Mr Stringer, saying he had been given this instruction by him on site on the day of the pour. The difference between the volume of concrete credited and the volume used was the result of raising the finished floor level and “the inconsistency in the flooring”. 132 Later emails refer to a meeting then being held between Mr Apostolakos and Mr Zilic. According to Mr Apostolakos, it was left for Mr Zilic to go away and check his area take-offs and get back to Contek with a final cost for each floor. The Hanson delivery dockets were sent to Mossop to confirm the delivered volume. 133 The dispute over these and other outstanding variation claims escalated a month later on 9 August 2017 when Mr Apostolakos sought confirmation of payment of Contek’s outstanding variation claims and threatened to suspend all work on site.76 The following email exchange shows that Mr Orlovic did not dispute Contek’s entitlement to be paid for additional concrete per se. He disputed the extent of the claim and required further substantiation by way of a survey to prove slab thickness. 74 Exhibit A3.1 pages 286-87. 75 Exhibit A3.1 page 286. 76 Exhibit A3.1 page 289-90. -- 29 of 106 -- [2024] SADC 1 28 134 Mr Orlovic promptly responded to Mr Apostolakos’ email by emotively saying among other things that Mossop was waiting on Contek to provide the delivery dockets for each truck, describing Contek’s claim as “way over the top”:77 We also believe that you need to prove to us that you used this amount of concrete on the project and where you used it… We have our doubts that your supplier supplied the amounts they claim too, because where did it go? 135 Mr Orlovic proposed Contek conduct a survey of the floor thickness to prove its claims. He reported that he and Mr Stringer had measured set-downs and averaged 65-75mm depths, with only a few 80-85mm. Yet he made no denial of the floor levels being raised due to inconsistencies in the Deltacore floor or despite the third mention of an on-site direction from Mr Stringer to raise the levels requiring additional concrete. 136 Mr Apostolakos replied, reporting on his earlier meeting with Mr Zilic and restating:78 The fact is the floor levels were raised from the original levels due to the inconstancy in the flooring system – this was instructed on site by the site supervisor… 137 Mr Orlovic replied again:79 We cannot just simply hand over circa $90K claimed without substantial evidence that raising the RL has increased concrete amounts by the amount you are claiming. The amounts claimed works out to about 100mm topping slabs throughout the whole slab area – an extra 40mm raised for the entire topping slab areas. On site [w]e don’t have 100mm topping slabs. The only way is to prove it to us by the survey as suggested. Please have this done and it will get the issue resolved quicker. Please include the guys above in any further correspondence as they are looking at this now, not me. I have only suggested ways to help you prove the actual thicknesses on site. We are not denying the RL’s were raised for levels 1 and 2. Also, please finish the works on site as soon as possible. It is getting to the critical stage now. Ramp drain base and ramp slabs, plus defects rectification. 138 Mr Orlovic’s focus on the topping slab thickness ignores the volume of concrete required for unexpected gaps (joints) and voids (infills) due to inconsistencies in the Deltacore floor. 77 Exhibit A3.1 page 289. 78 Exhibit A3.1 page 291. 79 Exhibit A3.1 page 291. Emphasis supplied. -- 30 of 106 -- [2024] SADC 1 29 139 A further exchange of emails occurred. Mr Apostolakos challenged the accuracy of a survey:80 …A survey will do nothing more than provide an approximate average, the dockets provide the EXACT cubic metres pumped and placed. We have stated our position clearly, that we believe the cause for the additional concrete placed was the inconsistency in the floor, and this was shown when the floor was checked for the level and there was as little as 0-10mm cover in places… 140 Mr Orlovic had the last word:81 Exactly! You are only entitled to be paid for anything additional to the 60mm topping and as advised for the ground floor there are 160mm sections that you should have allowed for, so in these areas anything over 160mm. The survey is the only way to prove the extra topping that was poured and that you are entitled to be paid for. 141 Mossop responded to the threat to suspend with a formal contract notice requesting recommencement of the works.82 142 In the 14 July and 9 August email exchanges Mr Orlovic made important concessions whilst the project was ongoing and when it should be expected that he was well aware of what had occurred on site and his memory had not been dulled or lost by the passage of many years. His oral evidence is to be viewed in this context. 143 Mossop’s submission that the importance of these concessions are overstated and should be seen as conciliatory should not be accepted.83 Mr Orlovic’s tone was not conciliatory. He was the Subcontract Superintendent. No dispute was raised about the alleged on-site direction to raise the levels for the first and second floors that was referred to three times. It was also accepted that the slabs for these floors were thicker than the specified 60mm because the levels were raised on these floors. Rather, the increased thickness of the ground floor was disputed. The key issues were the extent to which the raised levels required the volume of additional concrete claimed and how best the volume of additional concrete should be measured. Set-Down Measurements 144 Mossop employee Mr Lalli was then instructed to measure the topping slab thickness at the corners of each of the 32 bathroom set-downs on the first and second floors where there was no topping slab covering the Deltacore floor. Mr Lalli did not measure the ground floor set-downs because the prefabricated 80 Exhibit A3.1 page 294. 81 Exhibit A3.1 pages 294. 82 Exhibit A3.3 page 846. 83 Written Submissions of the Respondent [47]. -- 31 of 106 -- [2024] SADC 1 30 bathroom pods had by then already been installed. His results were recorded by hand on slab plans for each floor.84 145 His results are important evidence indicating a thicker than specified topping slab on the first and second floors and only contentious as a measure of reliable additional thickness. 146 In evidence Mr Lalli described how he took these measurements.85 He took a tape measure and got down on all fours, at eye-level, and at corners of the set- downs measured the distance from the top to the bottom of the slab that sat on top of the Deltacore floor. He hand-wrote his measurements on slab plans for each floor as he went. He took four or five measurements for each of the 64 set-downs. 147 Licensed surveyor Mr McFarlane suggested that to measure the slab thickness more accurately, a straight edge should have been used86 because it is difficult to read a tape measure, particularly with your head on the floor, and do it hundreds of times consistently.87 Further, the set-downs were not finished off nicely88 and accordingly the results were “a bit rough”89 and indicative rather than precise measurements.90 These criticisms should be accepted. Not enough measurements were taken, and they are localised to the set-downs that comprise only a small part of two of the three floors and are not representative of the entirety of the topping slabs.91 148 Whilst it should be emphasised Mr Lalli’s measurements are indicative only and not a basis for reliably calculating the average thickness of the topping slab or the volume of concrete used for the topping slabs, some useful inferences can be drawn from them, nonetheless. 149 Even allowing for a degree of error and imprecision in taking measurements that are self-evidently rounded,92 Mr Lalli’s measurements show material variability in the depth of the topping slab across both the first and second floors and, by implication, material variability in the height of the Deltacore floor panels underneath, on the assumption the topping slabs were flat on top. 150 Despite their imprecision, these measurements also indicate the topping slabs for the first and second floors were thicker than 60mm and in the majority of the measured parts, some 20 to 30mm thicker, bearing in mind the lower 84 Exhibit A3.1 pages 182 and 183. 85 T620.1-622.33. 86 T540.5-.6. 87 T560.15-31. 88 T541.1-.2. 89 T551.21-.22. 90 T552.11-.12. 91 Using Mossop’s figures for the ground floor, the set-downs only occupied 188.76m2 of a total area of 2462.26m2. See Table 5 of the Respondent’s Written Submissions at page 36. 92 All measurements are in 5mm or 10mm integers. -- 32 of 106 -- [2024] SADC 1 31 measurements indicate high points in the Deltacore floor panels and the higher measurements, low points. 151 For example, at the set-downs between gridlines E-C and 8-13 on the first floor the measurements range between 70mm and 90mm whereas those between gridlines H-G and 1-7 vary between 60mm and 80mm, with only one (45mm) measurement out of 37 under 60mm. At the set-downs for the last two rooms between gridlines F-D and 1-2, the measurements range between 80mm and 90mm with no measurements below 60mm whilst those for the next four rooms range between 50mm and 75mm, with only one (50mm) measurement below 60mm. Across a single set-down with a diagonal of some several metres, there are material variations. 152 Generally, the measurements for the first floor indicate additional concrete of up to 30mm thick in places, save for two measured places where the measurements recorded were 45mm and 50mm (indicating high points in the Deltacore floor) and minimum cover would not be achieved from the datum for the finished floor level set by the Mossop surveyor. 153 The measurements for the second floor also indicate additional concrete of up to a 30mm thickness, although the number of higher measurements in the range of 80 to 90mm is noticeably less than for the first floor. This is consistent with the other evidence showing that less additional concrete was used for the second floor slab than the first floor (e.g. the volume claimed for the first floor is 40% more than for the second floor).93 154 Most of the results exceed 60mm and indicate that more concrete than specified was used across the whole of each floor to ensure adequate cover for high parts of the Deltacore floor. Whilst the increase in the level of the finished slab appears to be material (since 20 to 30mm is one-third to half of the specified slab thickness) these measurements do not assist in reliably quantifying the volume of additional concrete required because the true extent of variability in the entirety of the topping slab is unknown. 155 Mr Lalli’s measurements support Mr Stringer’s recollection94 that around an additional 30 to 40mm of concrete was required to lift the topping slab to cover the top of excessively cambered Deltacore panels in the back left-hand area of the second floor, even bearing in mind Mr Lalli’s measurements are necessarily imprecise, and Mr Stringer was uncertain of his recollection from May 2017 as to the precise increase in the finished floor height.95 93 That is, 51.28m3 for the first floor and 72.16m3 for the second. 94 See [250]-[252] below. 95 T568-33-T569.1 -- 33 of 106 -- [2024] SADC 1 32 156 That said, Mr Lalli’s measurements do not support the ‘diminishing’ or ‘feathering down’ Mr Stringer described to work the higher concrete down to the design level.96 The Alexander Symonds Survey Purpose 157 Mr Lalli’s results were provided to Mr Apostolakos by email on 22 August 2017. He was told at the time that Mossop “still do not know where the extra concrete has gone” because the results did not support Contek’s variation claim to the extent Contek “would have hoped”.97 Mr Apostolakos was also told in this email that Mr Orlovic had instructed a surveyor to survey the floors and work out an average thickness of the topping slabs. 158 As already stated, the average floor thicknesses derived by Alexander Symonds were used in Mossop’s final assessment to calculate the volume of additional concrete it allowed and paid for Contek’s concrete variation claims. Instructions and Methodology 159 Mr McFarlane was instructed by Mr Orlovic to undertake a survey of the bottom of the Deltacore floor and top of the topping slab for the purpose of working out an average topping slab thickness. The survey results were plotted as a series of numbers and crosses on a series of slab floor plans and ultimately the Deltacore panel markings were overlaid to create a second revision of the survey results. The numbers recorded denote the floor thickness at the surveyed location marked by the adjacent cross. 160 As stated in the survey plan notes, floor thicknesses were calculated at surveyed locations as the difference between AsBuilt floor and ceiling RLs. The range of results indicates that the Deltacore floor panels were of varying levels, on the reasonable assumption the topping slabs were flat on top. 161 The survey results show material variability in the depth of the topping slabs across all three floors. 162 An average floor thickness was then derived from the floor thickness survey results. Slab thickness was derived by deducting the specified depth of a Deltacore floor panel (205mm) from the floor thickness results. The averages were: 96 T569.17-.32. 97 Exhibit A3.1 page 184. -- 34 of 106 -- [2024] SADC 1 33 Table 7 Floor Average Floor Thickness (mm) Average Slab Thickness (mm) Ground 262 57 First 283 78 Second 272 67 163 The derived averages show thicker topping slabs than specified for the first and second floors, thereby requiring additional concrete for the additional thickness. 164 In costing the proposed survey work for Mossop, Mr McFarlane proposed the most efficient method would be to survey as many convenient locations top and bottom per floor as could be done, allowing an eight-hour day per floor, and then they would spend a further day building a surface model of the top and bottom of each floor from which they would interpolate slab thickness inside the surveyed area.98 Cost efficiency therefore limited the number of results to be taken from the outset. 165 Mr McFarlane acknowledged at the time in correspondence with Mossop and again later in evidence that there were a number of other limitations with the derived average floor thicknesses. The first was that he did not have access to all areas of the site.99 To survey a location line of sight is required. That is, Mr McFarlane could only survey what he could see.100 There were already fixtures and fittings installed in the ceilings that obstructed his line of sight to the bottom of the Deltacore floor in the ceilings101 that were still exposed, and plaster ceilings had been installed in some rooms on the ground floor.102 Mr McFarlane was also unable to survey the same location on the top and bottom of the floor due to various obstructions. 166 As the survey plans show, there were also no points surveyed in a number of rooms such as at the back left-hand side of the first floor103 and some on the second floor.104 Nor were points taken on many, let alone every, Deltacore floor panel for cost efficiency and access reasons. 98 Exhibit A3.1 page 192. 99 Exhibit A3.1 page 202. 100 T557.19-.20. 101 T548.34-549.17; T550.8-.17. 102 T519.1-.6. 103 Exhibit A3.2 page 466. 104 Exhibit A3.2 page 467. -- 35 of 106 -- [2024] SADC 1 34 167 Mr McFarlane described how he derived floor thickness in the email covering his results as follows:105 The numbers on the plots show the Ceiling height difference with the above floor. The location of the numbers are at locations surveyed on the Ceiling. I worked out the thickness by using the floor AsBuilt completed, and creating a triangulated surface with those points, then, comparing to the ceiling pick up underneath. You will see that there are some thicknesses in the bathroom set downs. These have been created from interpolating the triangulated surface over the set down. 168 In evidence, Mr McFarlane confirmed the triangulation method was not an uncommon practice and would be within 5mm, that is +/- 2.5mm of accuracy.106 He said that the points above and below were taken within 5mm or so of one another.107 It should be accepted that the measurements of floor thickness at the surveyed points are accurate measurements. Average Floor Thickness 169 The same cannot be said of the average floor thickness for each floor derived from the measurements taken. As Mr McFarlane frankly acknowledged, the resultant model from which average floor thickness was derived was the best representation of the ceiling and floor surfaces that could be done bearing in mind the available time and access issues, although the floors were easier to survey than the ceilings.108 The data points are as exactly surveyed and accurate but average thickness is an “educated approximation”.109 170 In cross-examination, Mr McFarlane confirmed as correct the obvious proposition that average floor thickness was the product of the survey results taken and could be different in different places for differing reasons. For example, if extra shots were taken in thicker places, average floor thickness would be increased.110 When asked if he thought he had taken sufficient shots, he said he thought so but would have liked more shots in the finished areas (that is, the rooms he did not survey).111 171 Another limitation Mr McFarlane acknowledged was that the results did not take account of the ‘hog’112 in the Deltacore panels that could be as much as 15mm113 from the middle to the ends within a single panel. Nor did he consider differences between the Deltacore panels in setting his survey points as he would have liked.114 105 Exhibit A3.1 page 202. See also T514.1-.9. 106 T515.1-9. 107 T525.23-.37. 108 T520.5-.11. 109 T525.15-.21. 110 T552.1-.4. 111 T549.29-.33. 112 That is, deformation in the panel resulting in an upward curve. 113 Exhibit A3.1 page 202; T521.1-.9. 114 T549.14-.17. -- 36 of 106 -- [2024] SADC 1 35 172 In this regard, the plotted survey results overlaid on the Deltacore marking plans show that there was considerable variability between shots taken across the length of a single panel of some 20mm in some cases and negligible in others. The shots were generally taken in the same line along the length of a panel where taken, and not variably across their width. Many panels were not surveyed at all. On the second floor, the pattern of the survey points was noticeably sparse in the corridor between the rooms on the front. 173 The survey results used to derive average floor thickness included interpolated heights for the bathroom set-downs where there was no topping slab. There is no evidence explaining why these measurements were apparently included in deriving average topping slab thicknesses where there was no topping slab or how this affects the derived averages. Evidence of Inconsistency in Deltacore Floor 174 Putting aside limitations with the two surveys, both indicate a significant degree of variability in topping slab thickness, and assuming the finished floors were flat on top, significant variability in the height of the underlying Deltacore floor panels, both within a single panel and between different panels and between the three floors of the building. Level Topping Slabs 175 Whilst Mossop did not formally admit that the topping slabs were flat finished or level, its counsel conceded there was no evidence to suggest the finished top was not flat.115 176 The assumption that the finished floor levels of the topping slabs were flat or level (as alternatively described in the evidence) is reasonable on the evidence. Mr McFarlane considered the floors “pretty flat” on his observations and developed his model of the floor surfaces on that basis.116 Mr McFarlane’s unchallenged expert evidence should be given due weight on this issue. 177 Although his evidence on this issue is anecdotal and less reliable, Mr Lalli agreed in cross-examination that his measurements indicate changes in the height of the Deltacore floor panels rather than uneven topping slabs.117 178 Both Mr Apostolakos and Mr Stringer described in detail the process for finishing the topping slabs by vibrating the concrete to compact it and trowelling it to create a flat surface within reasonable tolerances.118 Mr Apostolakos’ evidence that the levels are checked at the end of a pour was not challenged.119 There is also no evidence suggesting the finished topping slabs were uneven other than the 115 T30.20-31.4. 116 T559.19-.20. 117 T624.1-625.11. 118 T206.35-207.4; T177.20-T178.12; T570.32-.36. 119 T414.8-415.20. -- 37 of 106 -- [2024] SADC 1 36 evidence Mr Stringer gave about ‘feathering’ part of the second floor. This evidence is not credible and contradicted by Mr Orlovic, who as Subcontract Superintendent was responsible for certifying Contek’s works. Documentary Evidence 179 The survey results support the other evidence as to ‘discrepancies’ and ‘inconsistencies’ in the Deltacore floor to the same effect. The contemporaneous documentary evidence has already been considered above, noting Mr Orlovic’s near contemporaneous acknowledgments that the levels on the first and second floors were raised.120 The Oral Evidence 180 There was much contention at trial about what was said by the relevant witnesses about the alleged on-site instruction given to Mr Apostolakos and Mr Kemp to raise the finished floor levels due to ‘inconsistencies’ in the Deltacore floor levels. Putting aside the differences between their accounts as to the result of such discussions, both Mr Orlovic and Mr Stringer gave evidence that supports Mr Apostolakos’ claims about uneven Deltacore floor panels causing a problem with the set level for the topping slabs achieving adequate cover on the ground and second floors. 181 Mr Orlovic gave evidence about “imperfections”121 in the Deltacore floor panels on the ground floor and the problem of not achieving in some place any122 or in others the required cover for the reinforcing mesh that was specified for the topping slab123 where the Deltacore was quite high. He specifically referred to cambers in the Deltacore panels being higher than they should be.124 182 Mr Stringer said there was a problem with the Deltacore floor at the back left-hand side of the second floor. He said he was approached on the second floor about not achieving cover over the Deltacore floor because the panels were or appeared more cambered than elsewhere.125 Since he was not on site for the ground floor pour, ‘elsewhere’ should be inferred as meaning the first floor. His evidence does not sit well with the survey evidence showing the first floor topping slab was on average materially thicker than the second and there was similar variability in the results for both floors. 120 See [120] above. 121 T706.8. 122 T706.32-.33. 123 T706.4-.19. 124 T706.1-.2. 125 T567.25-.31. -- 38 of 106 -- [2024] SADC 1 37 183 Whilst Mr Stringer did not recall the specific amount, he believed he told Mr Apostolakos and Mr Kemp to lift the floor by around 30 to 40mm because the panels were “excessively” cambered some 30 to 40mm, 40mm being the worst case scenario.126 Photographs 184 Mr Apostolakos gave evidence about the significant variation he said he observed in the levels of the Deltacore floor panels and the width of gaps between panels or the structural steel by reference to photographs taken during construction.127 185 Mossop in closing challenges his evidence as overstating the unevenness of the Deltacore floor and submits the photographs referred to were not representative and selective, complaining that Contek only took 15 photographs (referring to the photographs that were emailed to Mr Zilic in July 2017 as substantiation of Contek’s claim). Yet Mossop relies on only five more photographs in its written submissions which it asserts show the ‘flatness’ of the panels.128 On review, most of the photographs relied on by Mossop do not support its contention that the panels were evenly laid (i.e. flat). Most have been taken from too far a distance to be conclusive. Two show a distinct step down between panels in the background, consistent with the observations that should be made of the photographs referred to by Mr Apostolakos. 186 What is important is that there are photographs showing a distinct step down between panels, one most clearly shown by the straight level of a board sitting across panels of uneven height. There are others showing the Deltacore floor panels sitting at varying heights compared to the structural steel and it can be seen in a number that where four panels intersect, the intersection is irregular. 187 Contrary to Mossop’s submission, the photographic evidence taken together with the survey evidence does prove some Deltacore floor panels were out of level. The photographs are of assistance in understanding the nature of the significant variability in the levels of the Deltacore floor panels indicated by both Mr Lalli’s imprecise measurements and the derived slab thickness at the points surveyed by Alexander Symonds. Gaps and Voids 188 Self-evidently, neither Mr Lalli’s measurements nor the Alexander Symonds survey results have any bearing on horizontal ‘gaps’ and ‘voids’ in the Deltacore floor panels. The evidence about the extent of unexpected gaps and voids is limited and only indicates the nature of some examples. 126 T568.33-569.1: T569.25-.27. 127 T112-114; T122-124; T158-170. The photographs comprise Exhibit A3.2 pages 666 to 793. 128 Written Submissions of the Respondent [93]-[97]. -- 39 of 106 -- [2024] SADC 1 38 189 In evidence Mr Apostolakos described the Deltacore floor panels as poorly positioned, leaving too wide a space between them. He also complained about the gaps between panels and loose cutting around structural steel beams and posts. His complaint was verified by an email129 sent to Mr Barone that was copied to Mr Orlovic in March 2017 complaining about the excessive blocking required. His email referred to his previous complaint about the same problem on the ground floor. 190 Some of the photographs Mr Apostolakos referred to show distinct and uneven joints in between the Deltacore floor panels, varying gaps between the panels and structural steel, and gaps where there were rough cuts for connections. As already mentioned, there are places where four panels meet and their misalignment can be seen clearly, creating irregular joints and voids. There are some instances where the size of the joints between panels appears to vary between panels, but it is difficult to discern the dimensions and extent of these apparent inconsistencies across all floors. 191 In assessing the photographs that show a tape measure as a reference point across a joint, it should be borne in mind that panels placed at the specified width of 3mm at the base would be 46mm wide before the chamfer and 76mm at the top of the chamfer. When this is appreciated, it is apparent the joints depicted may not be as excessive as Mr Apostolakos claimed. 192 Mr Apostolakos also gave evidence about the significant work his crew did to block up gaps and voids to prevent the concrete from bleeding through. Blocking joints and voids to prevent concrete bleeding was part of Contek’s scope of work and it should be accepted that Contek did the work that was required properly, thereby minimising unnecessary waste despite his complaints. 193 In summary, on the evidence, it is apparent that there were some unexpected ‘gaps’ and ‘voids’ between the Deltacore floor panels and between adjacent structural steel as a result of the varying levels of the Deltacore panels and therefore some additional concrete was required to fill them. And despite the extensive work undertaken by Contek to block the gaps and voids, it is on the balance of probabilities inevitable that a material volume of additional concrete was required to fill these unexpected gaps and voids that Mr Apostolakos complained of in his evidence. 194 This additional volume is unquantifiable. QS Assessments First QS Assessment 195 To dispel any argument that the drawing changes required more concrete, Mossop instructed WT Partnership to measure the quantities of concrete specified in the tender (revision 00), contract (revision 01) and for construction drawings 129 Exhibit A3.3 page 813. -- 40 of 106 -- [2024] SADC 1 39 (revision 03) for the topping slabs. In a memorandum dated 8 August 2018, WT Partnership reported that the variance in concrete quantities between drawings was not significant.130 This unchallenged conclusion by professional quantity surveyors should be accepted. 196 For the topping slabs, the total volume of standard mix (the predecessor to the Helix mix ultimately used) ranged from 365.5m3 to 366.6m3 between the successive drawing issues. This compares to Contek’s lower allowance of 351.31m3,131 a difference of 14.04m3, about 4% for the measure taken off the tender drawings. 197 The difference primarily arises because WT Partnership’s measure includes 94.4m3 of 160mm thick concrete plus 96.7m3 of 60mm thick concrete for the ground floor compared to Contek’s allowance of 148m3 of 60mm thick concrete only. Otherwise, WT Partnership’s measure for the first and second floors was some 14% less that Contek’s. Second QS Assessment 198 Mossop instructed WT Partnership to undertake a further measure of the quantities of concrete including allowances for all gaps and infills based on the Deltacore shop drawings and adjust the quantities for “the surveyor’s levels”. This was a reference to the average slab thicknesses derived from the Alexander Symonds floor thicknesses survey. 199 In a memorandum dated 6 December 2018,132 WT Partnership reported that for the ground floor, the adjusted quantities fell closer to Contek’s original quantities than those claimed but for the first and second floors, were between the original and claimed volumes. 200 Included in WT Partnership’s report is its own remeasure of 333.6m3 as per the engineer’s specifications. It is not apparent which version of the drawings was used. It does not matter given the difference between them was not material according to their last report. 201 Despite the inclusion of additional concrete for gaps, infills and fillings to cored panels, WT Partnership’s measure is 17.86m3 less than Contek’s original take-off of 351.31m3 (a difference of about 5%). 202 It is also less than WT Partnership’s last measure from the drawings of around 365m3 (by a difference of about 9%). The reason for the difference between its measures despite the addition of volumes for the gaps, infills and fillings is because Mossop instructed WT Partnership to omit 95.8m3 of 160mm topping slab included in its previous take-off. WT Partnership was further instructed Helix 130 Exhibit A3.3 pages 932 to 939. 131 This is the precise figure, noting that the rounded figure of 148m3 was used in V2. 132 Exhibit A3.3 pages 962-77. -- 41 of 106 -- [2024] SADC 1 40 concrete was not used in the external areas.133 The measure for 160mm topping slabs was reduced to 6.1m3 for the ground floor only. 203 No measure refers to any separate allowance for wastage. 204 To state the obvious, save for the measure adjusted for the surveyor’s levels, the other measures assume the topping slab was not poured on an ‘inconsistent’ underlying Deltacore floor and there were no unexpected ‘voids’ or ‘gaps’ by reason of such inconsistencies. The adjusted measure for surveyor’s levels also does not measure any additional volumes for unexpected ‘voids’ or ‘gaps’, whether irregular joints or infills, arising from inconsistencies in the underlying Deltacore floor panels. 205 Mossop relied on WT Partnership’s adjusted measure for the survey levels in its final assessment of Contek’s concrete variation claims to reject any additional concrete for the ground floor and accept small volumes for the first and second floors. A comparison between Contek’s allowance and WT Partnership’s measure follows. Table 8 Ground Floor (m3) First Floor (m3) Second Floor (m3) Total (m3) Contek’s Allowance 148 111.24 92.22 351.46 WT Partnership Measure 129.2 142 103.6 333.6 The Issues Answered Issue 1: Was there an instruction or direction constituting a variation? The Implications of any Answer 206 This issue concerns a hard-fought factual dispute about whether in the circumstances found there was a direction or instruction given requiring additional concrete in the topping slabs to the Deltacore floors. 207 In hindsight these issues are a distraction where the evidence shows the topping slabs are materially thicker than specification in places. Contractual compliance issues aside, neither pleaded direction to vary the scope of the original topping slab works assists in resolving the essential dispute about how best to measure the additional volume of concrete claimed even if it is proven such directions were given. 133 Exhibit A3.3 pages 956-57. -- 42 of 106 -- [2024] SADC 1 41 208 As to the alleged on-site verbal direction, even if it were found the floor levels were directed to be raised by a fixed amount (whether that be by any of the heights the witnesses said), the volume of additional concrete cannot be calculated when poured on an uneven Deltacore floor. Neither the extent of variation in its levels is known nor the reference point by which the level of the finished floor was raised. Hence the measurement dispute. As to the change in concrete mix, it does not bear upon the measurement dispute in any way, as is explained later in these reasons. The Parties’ Cases 209 On the parties’ pleaded cases, it is common ground that there was no contemporaneous written direction to vary the finished floor levels or increase the thickness of the topping slabs issued by the Superintendent under the Subcontract. Contek’s pleaded case relies first on the change in the concrete mix specification which the evidence shows was confirmed in writing by Mr Orlovic and, secondly, on an oral direction allegedly given by Mr Stringer to Mr Apostolakos on site to raise the finished floor levels. 210 It is convenient to deal with the change in concrete mix first and then the alleged on-site direction. Change in Concrete Mix Direction to Vary 211 Mossop formally admits the concrete specification was changed to a Helix mix and the reinforcing mesh deleted134 entitling Contek to an adjustment of the subcontract sum. The relevant direction was made in email correspondence from Mr Orlovic 10 days before the ground floor topping slab was poured. 212 That is, on 10 January 2017, Mr Orlovic notified Mr Apostolakos by email135 that a Helix mix was permitted in lieu of reinforcing fabric with smaller aggregate and Mr Apostolakos was asked to get a specification for approval. Mr Apostolakos obtained the specification from the concrete supplier, Hanson, and emailed it to Mr Orlovic. The Helix mix was the subject of continuing email discussions in mid-January 2017 involving the external project engineer (Mr Wong), the Helix Australia representative (Mr Lloyd), Mr Orlovic, Mr Werner (Mossop’s then Site Supervisor), Mr Apostolakos and Contek’s Site Supervisor (Mr Kemp).136 213 During this exchange of emails, the engineer advised that the Helix fibres were only to be used for the Deltacore topping slabs to manage shrinkage and were not to be used as a replacement or hybrid for the reinforcement of the raft slab and footing beams. He said whilst Helix fibres may be used in those areas, the reinforcement detailed in the structural drawings was still required.137 He also confirmed the thickness of the topping slabs using the Helix mix was to be 134 See paragraph [69] below. 135 Exhibit A3.1 page 144j. 136 Exhibit A3.1 pages 144a to 144h. 137 Exhibit A3.3 page 796. -- 43 of 106 -- [2024] SADC 1 42 60mm,138 consistent with the slab thickness detailed in the structural drawings that never changed. 214 On its face, this direction to vary does not concern any voids or inconsistencies in the Deltacore flooring on which the topping slabs were required to be poured. 215 However, Mr Orlovic gave evidence that the change to a Helix mix in lieu of reinforcing mesh was because of “imperfections” in the Deltacore panels causing there to be insufficient or no cover for the reinforcing mesh.139 As Mr Orlovic put it, this was a way around there being no or insufficient cover in some areas of the Deltacore and was the subject of on-site discussions he had with Contek’s Site Supervisor Mr Kemp, and perhaps Mr Apostolakos, as regards the ground floor a week or so before the first pour on 20 January 2017. 216 The effect of Mr Orlovic’s evidence was that at the highest points of the Deltacore panels there would be little or no concrete cover over the reinforcing mesh if the concrete was poured to the required level from points that were 40 to 60mm lower that the higher point from which the datum for the finished floor level was set. 217 Mr Orlovic also said that the solution adopted did not “necessarily give you more height,”140 that is, require a thicker topping slab. As a matter of logic, Mr Orlovic is correct. His evidence confirms that the direction to change to a Helix mix in lieu of reinforcing mesh did not require an additional volume of concrete or constitute a direction to raise the finished floor levels. Whilst it is an important contextual matter, more was required to be said for it to have the effect alleged by Contek. 218 Accordingly, Contek’s reliance on the change in the concrete mix as a basis for requiring the supply of additional concrete for the topping slabs is misplaced. Increased Fluidity 219 The allegation made at trial that the Helix mix was less viscous and had a higher slump rating (meaning it was more fluid) than the standard mix was not pleaded by Contek. Nor was it pleaded that this characteristic contributed to the increased volume of concrete required for the topping slabs. 220 Nonetheless, Contek conducted its case at trial on the basis that this characteristic was a contributing factor justifying in part its concrete variation claims.141 138 Exhibit A3.1 pages 144a and 144b. 139 T705.26-706.33; T726.11-727.1. 140 T706.26. 141 First Trial T12.28-33. Second Trial T6.32-.38; T8.29-.31; T33.1-.18. -- 44 of 106 -- [2024] SADC 1 43 221 Mr Apostolakos was the only witness who gave evidence on this topic and no objection as to relevance was taken during his evidence. His unchallenged evidence as to the difference between the mixes was that the Helix mix involved “a slightly different slump”142 and smaller aggregate with a higher water content.143 222 Whilst his evidence establishes that a Helix mix would freely flow into cracks, gaps and voids between and in the Deltacore panels, there was no evidence about much how more freely it would flow compared to a standard mix reinforced with mesh. 223 It follows that, all things being equal, the change in the fluidity of the concrete mix absent reinforcing mesh did not require an increased volume of concrete to pour the topping slabs. However, it is a different and important issue as to whether the evidence establishes that the Helix mix did flow freely into any cracks, gaps and voids between and in the Deltacore panels as alleged by Contek. Conclusion re Changes in Concrete Mix 224 In summary, it must be accepted that the direction to vary the concrete mix and omit the reinforcing mesh from the 60mm topping slabs did not require any variation to the finished floor levels or slab thickness or additional concrete for unexpected or known ‘gaps’ or ‘voids’. It was an alternative design to address insufficient coverage of the reinforcing mesh and did not address the related but different issues of insufficient topping slab thickness in some areas of the Deltacore flooring. There is no probative evidence that any increase in the fluidity of the concrete required additional concrete. On-site Direction to Vary Concessions made at Trial 225 This issue concerns the factual dispute as to whether an on-site direction was given to raise the finished floor levels requiring more concrete as alleged or otherwise. 226 Both parties’ pleaded cases shifted during trial. Contek’s case changed in the course of Mr Apostolakos’ cross-examination about material circumstances of the oral direction. Mossop’s pleaded case also shifted. In opening Mossop’s case, its counsel made two significant concessions contrary to its pleaded case that there were no unexpected or unknown inconsistencies in the Deltacore floor, and no on- site directions were given to raise the finished levels of the topping slabs. 142 First Trial T190.37-191.9. 143 T176.23-.36. -- 45 of 106 -- [2024] SADC 1 44 227 The first was to the effect that Mr Stringer had given an oral direction to Contek to raise the finished floor level, but it was only for part of the second floor.144 Mr Stringer later gave evidence to this effect and said it was due to excessive cambers in the Deltacore floor in that section of the second floor. 228 The second was that there was an on-site discussion between Mr Apostolakos and Mr Stringer when the first floor balconies were being poured that led to additional work to form rebates for the fixed windows and rebates were installed on both the first and second floors145 but not to the extent asserted by Mr Apostolakos. 229 As already mentioned, Mr Orlovic then gave evidence in Mossop’s case of on-site discussions that occurred with Mr Kemp, and perhaps a second with him and Mr Apostolakos, during Contek’s preparatory works for the ground floor pour. These discussions concerned the problem caused by ‘imperfections’ and cambers in the Deltacore floor that reduced cover for the reinforcing mesh in the topping slab. This led, he said, to a change in the concrete mix but he denied he gave any direction to raise the finished floor level requiring additional concrete for the ground floor topping slab (or indeed the other two floors). Mr Apostolakos’ Evidence 230 Unsurprisingly, Mr Apostolakos’ evidence-in-chief was consistent with Contek’s pleaded case. In cross-examination, he confirmed his earlier evidence about the discussions he had with Mr Stringer on-site early on the morning of the first pour for the ground floor. He described again in detail how he and Mr Kemp in the course of checking the levels identified that there would be little or no cover in places due to the unevenness of the Deltacore floor. The problem was raised with Mr Stringer. He recalled them discussing raising the finished levels and after Mr Stringer left to make a call and returned, being told to raise it from the highest point of the uneven Deltacore floor. He repeated multiple times he was told to raise the level by 40 to 50mm from the highest point and recalled being concerned that would be less than specification in places.146 231 Mr Apostolakos’ memory about what happened on the first and second floors was by his own account less clear. 232 After committing to there being a second conversation on the first floor, he said he could not recall where the conversation took place or whether it was with Mr Stringer or someone else from Mossop, possibly Mr Orlovic. He made mention of a precedent being set on the ground floor.147 When pressed, he thought it was either Mr Stringer or Mr Orlovic, but could not say who.148 He was sure that the 144 T494.10-.25. 145 T494.26-495.4. 146 T390.4-.23; T394.38-T397.12. 147 T391.8-.10. 148 T391.1-T393.3. -- 46 of 106 -- [2024] SADC 1 45 first and second floors were both raised by 30mm149 and less than the ground floor, and on an instruction from Mossop, but he could not remember who gave him that instruction. His evidence was consistently it could have been either of Mr Stringer or Mr Orlovic. 233 As to the need to install rebates for the prefabricated windows, Mr Apostolakos agreed that this was a separate discussion with Mr Stringer that occurred after the levels were raised on the first floor. 234 When it was finally put to him in cross-examination that it was not possible that the ground floor discussion took place with Mr Stringer because he had not yet started working for Mossop, Mr Apostolakos accepted this possibility and said it could have been with Mr Orlovic.150 235 Mr Apostolakos denied that the conversation he had with Mr Stringer on the second floor only concerned part of the floor.151 236 Clearly, there are significant conflicts between the accounts of Mr Apostolakos, Mr Stringer and Mr Orlovic about the on-site discussions concerning ‘inconsistencies’ in the Deltacore floor and what followed. 237 As already stated, to a large extent these conflicts are explained by their limited and less than reliable recollections of the detail of events that occurred some five and half years before they gave evidence. 238 Nonetheless, the evidence of each was unsatisfactory on this topic for different reasons in some important respects. 239 In evidence-in-chief, Mr Apostolakos was firmly committed to the position he had taken in his email exchanges with Mr Orlovic when the dispute first arose in July and August 2017. His change of position in cross-examination about important aspects of the oral directions allegedly given by Mr Stringer was unsatisfactory and causes doubt about other aspects of his evidence on this topic, requiring a careful review of his evidence where it is contentious. 240 One explanation is that Mr Apostolakos conflated a number of on-site discussions and was mistaken about the timing of the first discussion and with whom from Mossop it was. There was marked similarity between his account and that of Mr Orlovic as regards walking around the site checking levels152 against the datum level for the finished floor level,153 suggesting that he was recollecting that occasion and therefore was involved in at least two relevant discussions (accepting Mr Stringer’s evidence of a discussion on the second floor). Another is that Mr Apostolakos had forgotten about the earlier discussions with Mr Orlovic that 149 T393.10-.11; T393.27-.32. 150 T398.25-399.7. 151 T399.15-.25. 152 T706.17; T725.21-727.1. 153 T725.4-726.37. -- 47 of 106 -- [2024] SADC 1 46 occurred during preparation for the ground floor pour and was recalling a further discussion he had on the morning of the first pour with the outgoing Mossop Site Supervisor Mr Werner, who was not called to give evidence. 241 Both are likely explanations on all the evidence and ultimately it does not matter which explanation is right, for the following reasons. 242 That is, two things lead to the conclusion that Mr Apostolakos was not fabricating his evidence to suit his case as suggested by Mossop. First, the levels were raised for all the floors to varying extents154and someone from Mossop in setting the levels gave that site instruction because it would be extraordinary for Contek to have poured to a different level than that specified by Mossop. Mossop never suggested so and Contek’s works were certified. 243 Accepting Mr Orlovic’s evidence that it was not him for the first and second floors, then it was most likely Mr Stringer who gave the direction for those floors, which Mr Stringer at least accepts for the back part of the second floor. Mr Orlovic’s Evidence 244 Mr Orlovic’s evidence about problems with the unevenness of the Deltacore floor leading to the change of concrete mix was surprising, yet his account of walking around the site to discuss the problem and possible solutions fits with Mr Apostolakos’ recollection of doing the same thing. The timing of Mr Orlovic’s on-site discussions is also consistent with the email he sent Mr Apostolakos on 10 January 2017 referring to a discussion the day before and telling him that they were allowed to use the Helix mix instead of the reinforcing mesh.155 245 However, Mr Orlovic’s denial that he gave Contek any instruction to raise the finished floor level156 on the ground floor is questionable for two reasons. 246 First, the AsBuilt slab thicknesses surveyed by Alexander Symonds show a range of survey points where the topping slab is thicker than 60mm. On the ground floor (which is the most contentious) the measured thicknesses are highly variable. The topping slab exceeds 60mm by up to 26mm in some parts and in others is between 20 and 45mm lower than 60mm. That is, the range of surveyed thickness is some 70mm. For example, the surveyed floor thicknesses in the left half of ‘South House’ range between 268mm and 286mm, equating to slab thicknesses of between 63mm and 81mm,157 indicating the finished floor level was raised for the slab to be thicker than specified. At the other end of ‘South House,’ floor thicknesses are predominantly less, indicating many high points in the underlying Deltacore floor and the problem identified about achieving adequate cover. 154 Because the topping slab is greater than 60mm in some of the surveyed places. 155 Exhibit A3.3 page 805. 156 T713.18-.20. 157 Exhibit A3.2 page 471. -- 48 of 106 -- [2024] SADC 1 47 247 Secondly, Mr Orlovic agreed in cross-examination that 10-20mm of Helix concrete would not provide a sufficient topping slab. He said he checked the minimum cover with the engineer. He could not remember the exact figure, but thought it was “maybe 30mm”.158 Contemporaneous email correspondence shows the engineer confirmed that 60mm was the required thickness of the Helix topping slabs (except where specified to be 160mm).159 Mr Orlovic also accepted he would not have made a decision to change slab thickness without consulting the project engineer.160 248 The engineer’s written confirmation should be accepted as the required minimum thickness for the Helix topping slabs in the absence of any cogent evidence to the contrary, consistent with the 60mm concrete thickness specified on the structural drawings. 249 Ultimately, having regard to the floor thicknesses survey results for the ground floor and the importance of compliance with the engineer’s specification as to 60mm concrete, it is likely that Mr Orlovic did instruct the finished floor level for the topping slab to be raised in the course of the discussions he said he had about the problem of lack of cover due to ‘imperfections’ and cambers in the Deltacore floor and his denial that he did not should be rejected. Mr Stringer’s Evidence 250 The most unsatisfactory witness on this topic was Mr Stringer. His account of the discussion with Mr Apostolakos and Mr Kemp on the second floor about lifting the concrete by 30 to 40mm in the far left-hand side and then ‘diminishing’ or ‘feathering’ it down over the rest of the floor to the design height is not credible, undermining the rest of his evidence on this topic. Mr Orlovic strongly rejected the proposition that such a direction would ever be given or that the floor was constructed with a slope.161 It is, using Contek’s expression, ‘fanciful’ to think the floor was poured out of level on the instruction of a reputable and professional builder such as Mossop. Mr Apostolakos’ denial that their discussion was limited to only part of the floor or that the floor was poured out of level should therefore be accepted.162 251 Mr Stringer’s evidence about what happened on the first floor was equivocal. He first denied giving any instruction for the first floor then in cross-examination ultimately conceded he had no recollection of the pour for the first floor “at all”163 and he had no memory or knowledge of the first floor level being lifted.164 That was despite Mr Stringer being party to the earlier emails querying Contek’s first concrete variation claim V2 and measuring the set-downs with Mr Orlovic to 158 T726.16-.35. 159 Exhibit A3.1 page 144a. 160 T715.22-716.2. 161 T723.1-.22. 162 T408.3-.17. 163 T599.28-.37. 164 T599.37-600.10. -- 49 of 106 -- [2024] SADC 1 48 ascertain the thickness of the topping slab in August 2017 and making no objection to Mr Apostolakos thrice stating he was given an oral direction to raise the floor levels by him. It is apparent Mr Stringer knew more than he let on and was not being entirely frank with the Court about what happened. Accordingly, Mr Stringer’s evidence on this topic should be rejected where it is contentious. 252 Contek’s claim that Mr Stringer gave a direction to raise the finished floor level for the first and second floors should be accepted and Mossop’s contention that it was limited to only part of the second floor rejected. Conclusions 253 The Deltacore floor panels were installed on the ground floor in early January 2017. During the course of preparatory works for the ground floor concrete pour, Mr Kemp and Mr Apostolakos identified problems with the varying levels and excessive cambers in the Deltacore floor that were brought to the attention of Mr Orlovic as Project Manager and Subcontract Superintendent. 254 These problems are consistent with the best evidence of the nature of the ‘inconsistencies’ in the Deltacore floor panels, that is, the Alexander Symonds survey results. These results show there were significant and highly variable ‘inconsistencies’ in the Deltacore floor on all floors by reason of their unevenness including due to excessive cambers. The ground floor exhibited the highest degree of variability between high and low points. 255 Mr Orlovic met Mr Apostolakos and Mr Kemp on site and during the course of walking around the floor checking the levels, possible solutions were discussed, including changing the concrete mix and removing the reinforcing mesh. There were further discussions, and the project engineer was consulted about the change in concrete mix. Whilst the concrete mix was changed and that ultimately solved one problem, to achieve the specified cover of 60mm the finished floor level had to be set from a higher point than otherwise because of the uneven and excessively cambered Deltacore floor. 256 Mr Orlovic orally directed Contek to pour the ground floor to a higher finished level, requiring more concrete than if the underlying Deltacore floor had been evenly laid as specified. It is unnecessary to resolve whether a direction was given on the morning of the first pour or earlier. 257 The evidence does not permit a finding as to the extent to which the level on the ground floor was raised or what additional volume of concrete was required. 258 The precedent was set on the ground floor. With Mr Orlovic’s knowledge and approval, Mr Stringer directed the floor levels to be raised on the first and second floors on the mornings of the pours or shortly beforehand in preparing for the pours when checking the levels with Contek. The levels for the first and second floors were raised some 20 to 30mm. There was no ‘diminishing’ or ‘feathering’ down of the higher back third of the rest of second floor. -- 50 of 106 -- [2024] SADC 1 49 259 As discussed above,165 resolution of this issue does not resolve the measurement dispute. Breakouts 260 It is uncontentious that the subcontract scope of works and drawings specified for sections of some Deltacore panels to be broken out to enable top and bottom reinforcing to be installed between the Deltacore floor panel and the edge beams and then filled with Helix concrete.166 Mossop’s submission that a competent concreter would have allowed for the extra concrete for breakouts should be accepted. These volumes were measured and reported in WT Partnership’s December 2018 report. Issue 2: Are these variation claims contractually barred? The Subcontract Variation Provisions 261 Clause 24 of the subcontract conditions167 addresses the respective rights and obligations of the parties regarding variations to the subcontract scope of works. 262 A variation to the subcontract scope of works may arise in two circumstances. 263 The first is an express written direction issued by the Subcontract Superintendent (Mr Orlovic) (the Superintendent) that has the effect of varying the Scope of Works.168 This is provided in clause 24.1 as follows. 24.1 The Scope of Works may only be varied by an express written direction to that effect for [sic] the Subcontract Superintendent. 264 The second circumstance is provided in clause 24.2: 24.2 If the Subcontractor considers an instruction or direction (not expressed to be a Variation) constitutes a Variation it must notify the Subcontract Superintendent before commencing the work as varied. 265 There are no contractual definitions of “variation” or “Variation” or “direction”. “Variation” should be understood as fundamentally meaning alteration by way of an addition or deletion to the subcontract scope of works, whether materials or labour. The composite expression “instruction or direction” is used throughout the rest of the clause in contradistinction to a “direction to vary”. The ordinary meaning of direction should be inferred: that is, '“an instruction as to what to do, how to proceed or where to go”: The New Shorter Oxford Dictionary”’.169 165 See [207]. 166 Section W on drawing S23 and Section 14 of drawing S22. 167 Exhibit A1 pages 199-200. 168 As defined. For convenience, defined terms will be capitalised and not defined further unless relevant. 169 Diploma Construction Pty Ltd v Marula Pty Ltd [2009] WASCA 229 at [63]. -- 51 of 106 -- [2024] SADC 1 50 266 The term “instruction” is defined in the subcontract as “any form of written confirmation provided by the Builder”.170 Notably, the term “direction” is not only undefined but unqualified: there are no requirements as to its form or from whom it should emanate, whether that be the Superintendent or some other representative of the Builder. 267 There is also no prescribed form of the notice required by clause 24.2. 268 It follows that clause 24.2 applies where there is an instruction (as defined in writing and from the Builder) or a direction in any form from either the Builder or the Superintendent. 269 Where clause 24.1 applies, it is implicit that clauses 24.5 to 24.9 apply and the Subcontractor must follow the procedures set out in those clauses. That is, in accordance with clause 24.5, the Subcontractor shall notify the Builder (Mossop) of its estimate of the value of the work claimed to be a variation and provide an itemised breakdown no later than five business days after the direction to vary the works is issued. An itemised quotation is to be provided complying with the requirements of clause 24.7. Under clause 24.9, the Builder upon review may request further documentation to support the itemised quotation. 270 A valid direction to vary the scope of works is not sufficient of itself to constitute an entitlement to adjust the Subcontract Sum.171 The Superintendent’s assessment of the value of a variation claim is necessary,172 following which the Builder will issue a variation order and the value of the variation will be added to or deducted from the Subcontract Sum.173 271 Clause 24.5 does not on its terms operate as a bar to claim. The consequences of failure to comply with clause 24.5 are expressly provided in clauses 24.11 and 24.12. Should the Subcontractor not comply with clause 24.5, the Superintendent must determine a fair and reasonable value of the variation claim which must be adjusted against the Subcontract Sum and such determination shall be final and binding upon the Subcontractor and the Builder. 272 Where clause 24.2 applies, it is then for the Superintendent “to consider” whether the instruction or direction is a direction to vary the Scope of Works (clause 24.3) or not (clause 24.4). If considered so, then the procedures under clauses 24.5 to 24.9 must be followed towards an assessment of the fair and reasonable value of the variation claim. If considered not, the Subcontractor must proceed to comply with the instruction or direction, and there is no variation to the Scope of Works in accordance with clause 24.1. 170 Clause 1.12 of the subcontract conditions, Exhibit A1 page 186. 171 Clause 24.17. 172 Clause 24.10. 173 Clause 24.13. -- 52 of 106 -- [2024] SADC 1 51 273 Where the Subcontractor disputes the Superintendent’s assessment as to entitlement to a variation or valuation, the Subcontractor’s remedy is a claim for breach of contract. The subcontract does not contain any terms providing any time bars for disputing the Superintendent’s assessment. 274 Clause 24.2 also does not on its terms operate as a bar to claim. It merely mandates that the Superintendent be notified before the Subcontractor commences the relevant work where it considers an instruction or direction not expressed to be a “Variation” constitutes a “Variation”. Breach would otherwise sound in a remedy for damages, a claim that was not made in this case. 275 For completeness, clauses 24.15 to 24.18 should be mentioned. They are anomalous in so far as they require the Builder’s agreement to specified matters that do not sit well with the rest of clause 24 that otherwise expressly confers the authority to issue directions to vary the scope of works, and assess and determine a fair and reasonable value for variation claims on the Superintendent, and not the Builder. Given these provisions did not form part of the parties’ pleaded cases and were not agitated at trial, the Court is not required to consider them further. To do so would be inappropriate and unfair. Consideration 276 Mossop’s pleaded defence of contractual bar is made in answer to Contek’s claim that the subcontract works were varied by Mossop by requiring first a change to the concrete mix for the topping slabs174 and, secondly, for additional concrete to be supplied to raise the finished concrete level due to significant voids and inconsistencies in the Deltacore floor installed by and the responsibility of Mossop.175 277 This defence is pleaded in the most general of terms as follows: 6.1.2 In relation to paragraph 6.1.2: … 6.1.2.2 Say that the Applicant did not comply with the contract pertaining to notification of variations but… 278 In its closing submissions, Mossop contended that there was no variation notice pleaded or given and Contek’s concrete variation claims are in the absence of such notice contractually barred by clause 24.2 of the subcontract.176 279 The first contention is correct in so far as no clause 24.2 notice is pleaded by Contek or in fact was given before the works claimed to be varied were commenced. However, on the terms of clause 24.2, failure to notify the Superintendent before commencing the works claimed to be varied does not bar 174 Claim [6.1.1]. 175 Claim [6.1.2]. 176 Written Submissions of the Respondent [25(b)] and section F [48]-[52]. -- 53 of 106 -- [2024] SADC 1 52 Contek’s entitlement to claim a variation. The preferable view is that notice provisions such as 24.2 are construed contra proferentem. A bar needs to be drawn in express and clear language if it is to operate as a condition precedent to entitlement or to extinguish a right to claim.177 Clause 24.2 does not contain any language that would suggest that non-compliance with clause 24.2 would create a bar to claim. 280 It follows that breach only sounds in a claim for damages for breach of contract by the Builder (Mossop). No such claim was made in this case. 281 Mossop’s pleaded defence plainly concerns failure to give notice of variations. It does not raise any non-compliance with clause 24.1 or defence of contractual bar arising in the absence of an express written direction from the Superintendent to vary the scope of works. Mossop should be confined to its pleaded case. Bearing in mind that Mossop assessed each of the concrete variation claims and issued payments schedules adjusting the subcontract sum, Contek’s submission178 that it would have pleaded an estoppel or waiver that would have succeeded if this defence had been pleaded should be accepted. Conclusion 282 The answer to the question as to whether Contek’s concrete variation claims are contractually barred is therefore no. Issue 3: Is the Alexander Symons survey result binding? Consideration 283 Mossop pleads that in about August 2017, it was agreed between the parties that Alexander Symonds would calculate the additional concrete used in the works, that the parties would share the costs and Mossop would pay for any additional concrete in the topping slabs according to the survey results.179 There are no material facts or particulars pleaded. 284 At trial, this agreement was alleged to have arisen during the ongoing dispute about the additional concrete claimed and to be evidenced in email correspondence. The first mention is in an email authored by Mr Tziortzis to Mr Apostolakos sent on 22 August 2017, in which he clearly ‘verbals’ Mr Apostolakos in a discussion they apparently had the day before.180 I've also attached the correspondence between Harry and the surveyor. Since our conversation yesterday, Harry has instructed the surveyor to proceed as per his instruction and marked up drawings in the attached emails. I think you will agree that the resulting survey will be very thorough and provide an accurate depiction of the topping slab thickness. As we agree [sic] on the phone yesterday, if the surveyor’s findings substantiate your claims in their entirety, Mossop will wear the cost of the surveyor. If the agreed 177 Commonwealth v Jennings Construction Ltd [1985] VR 586. 178 T830.13-.37. 179 Defence [6.1.3], [6.3.2] and [6.5.1]. 180 Exhibit A3.1 page 184. -- 54 of 106 -- [2024] SADC 1 53 variation value is at Mossop’s value or somewhere in between, the cost will be split 50/50 between Mossop and Contek. 285 Mr Tziortzis’ email says nothing about the parties agreeing to be bound by the Alexander Symonds survey. He used the word “substantiate” and the subject of the agreement concerned is the sharing of the costs of the survey depending on the results. The email does not go so far as to record an agreement that the results be determinative of the claims and the parties bound by that outcome. 286 Mr Apostolakos gave unequivocal evidence that he never agreed to be bound by the results of the Alexander Symonds survey.181 He convincingly repeated in oral evidence what he had told Mossop on 9 August 2017 in no uncertain terms that he thought the actual volumes delivered were more accurate than a theoretical survey.182 287 Mr Tziortzis was not called to give evidence. His absence is unexplained. Yet Mossop submits that Mr Tziortzis’ email should be preferred to Mr Apostolakos’ evidence given for the first time five years later. This submission is unpersuasive. Nothing should be inferred from Mr Apostolakos’ silence in August 2017 in challenging Mr Tziortzis’ email in the context of the escalating dispute over the concrete and other variation claims. 288 It should be accepted that it was Mr Orlovic’s insistence on a survey being done that led to Alexander Symonds being instructed and Contek did not agree to be bound by its results. Conclusion 289 The evidence does not support Mossop’s contention that the parties agreed that the Alexander Symonds survey would resolve their dispute. The answer to the question whether the Alexander Symonds survey result is binding in valuing Contek’s concrete valuations is no. Issue 4: Was Contek’s standard concrete allowance adequate? The Parties’ Contentions 290 Contek submits the concrete volumes allowed as a credit in Contek’s variation claims are reasonable, emphasising two matters. First, that Mossop in its final assessment of these variation claims adopted these very same volumes in calculating the credit given by Contek and accepted by Mossop for the superseded standard mix. Secondly, WT Partnership’s December 2018 measure of the topping slab is less than Contek’s allowance, bearing in mind WT Partnership’s measure was taken from the engineering drawings and included joints, infills and fillings and the 160mm thick concrete slabs as instructed by Mossop. 181 T213.10-214.11; T241.6.-.17. 182 Exhibit A3.3 page 835. -- 55 of 106 -- [2024] SADC 1 54 291 Mossop’s pleaded defence puts in issue ‘expected voids and inconsistencies’ that should have been included in Contek’s tender allowance (albeit referred to as a ‘quotation’) by its denial that there were any ‘unexpected’ or ‘unknown’ ones. In denying liability for any further additional concrete, Mossop further alleges that the estimate of the topping slab concrete volumes by WT Partnership was less than the volumes paid for. Mossop is here relying on the measure adjusted for the survey levels and not the measure taken off the engineering drawings for the standard concrete. 292 At trial, of WT Partnership’s concrete measures only the final one adjusted for the surveyor’s levels was relied on by Mossop as the measure of the actual volume of concrete used in the topping slabs.183 Instead, Contek relied on these measures as supporting the reasonableness of Contek’s allowance for the credit given and accepted by Mossop for the superseded standard mix. 293 In closing written submissions, Contek submitted its allowance was not in dispute. 294 That was clearly not Mossop’s position. Mossop disputes Contek’s concrete allowances as inadequate and therefore materially underestimating the volume of concrete required for the topping slab scope of works. 295 This was made clear from the outset of the trial. In the course of Contek’s counsel opening on the concrete variation claims, there was a long exchange between the bench and Mossop’s counsel about what was in dispute. Mossop’s counsel confirmed multiple times that Mossop’s case was that Contek’s take-offs were wrong and therefore there was more concrete used than should properly have been allowed by a competent concrete contractor. Further, the concrete had not gone into the topping slabs but had gone to other places ‘as expected’.184 In Mossop’s narrative for Topic 3 (prepared well before the first part of the trial), inadequate estimating was clearly identified as one explanation for extra concrete consumption.185 296 No objection was taken by Contek during the trial about being surprised by a case it did not know it had to meet. Contek opened and led detailed evidence from Mr Apostolakos about Contek’s allowance for concrete based on the tender drawings and wastage.186 183 T497.22-.34. 184 T23.4-25.1. 185 Page 2. 186 T195.5-201-24. -- 56 of 106 -- [2024] SADC 1 55 297 Mossop’s final challenge to the reasonableness of Contek’s concrete allowance was presented in its written closing submissions. These submissions introduce for the first time extensive and detailed technical analysis of the relevant drawings.187 298 Contek objects to the Court having regard to these parts of Mossop’s written closing submissions which it describes as “a glorified expert’s report masquerading as closing submissions”, apparently the work of Mr Neil Mossop and a further attempt by him “to influence and direct the evidence in circumstances where he is neither a witness of fact nor any expert”. 188 299 As stated earlier,189 Mr Mossop was not qualified as a testifying expert witness and he has no status as an expert witness. Accordingly, the Court has treated Mossop’s written submissions (including the narratives prepared on Mr Mossop’s instruction) as submissions on the technical issues arising, not evidence. Whilst it is regrettable that the Court has not had any real assistance in considering this material from the Applicant or an independent testifying expert called by either party, the Court has reviewed both Mossop’s submissions and the relevant documentary evidence carefully, as it is obliged to do, bearing in mind that the concrete volumes allowed as a credit in Contek’s variations claims are an essential component of its claims. The Court has made its own determination of what may be inferred from the relevant drawings. Evidence of Take-offs 300 As stated, the concrete volumes allowed as a credit in Contek’s variations claims total 351.46m3.190 301 Contek’s tender take-offs showing how it calculated the volumes allowed in pricing the topping slab scope of works were not in evidence. Ultimately, this does not matter. Contrary to Mossop’s submission, it is not necessary for the Court to assess Contek’s tender take-offs.191 What is required is for the Court to determine whether the volumes allowed as a credit are a reasonable allowance for the concrete required to pour the topping slabs including specified joints, infills and fillings as specified in the relevant drawings. Since Contek has presented its claims by floor, the Court should also determine the reasonableness of Contek’s allowance for standard concrete on a floor by floor basis, not globally. 187 I.e. following from pages 33 to 67, the major part comprising an analysis of the topping slab concrete volumes by reference to the drawings. 188 Contek’s Skeleton Reply Submissions (FDN 93) [3]. 189 See [38]-[39] above. 190 See Table 6 at [117] above, noting V2 rounds up the claimed net volume to 148m3 from 147.8m3. 191 Written Submissions of the Respondent [148]-[150]. -- 57 of 106 -- [2024] SADC 1 56 302 In this regard, Contek relied on take-offs192 prepared from the drawings sent to Mossop in July 2017 to substantiate its claims.193 Mr Apostolakos’ unchallenged evidence was the required standard concrete volumes in metric cubes were calculated by simply multiplying the areas of each of the topping slabs by 60mm. As stated, the measures of the relevant areas are not contentious.194 303 Mr Apostolakos gave evidence195 that there were two versions of the take- offs prepared in 2017 in addition to the original tender take-offs. The first was incorrectly calculated with the bathroom set-downs included in the floor areas (even though there was no topping slab in these areas) and no wastage was allowed, the set-downs equating to wastage. In the second calculation, the bathroom set- downs were left out and wastage was separately allowed, as he said was done for the tender take-offs. He said it worked out the same because leaving in the bathroom set-downs covered wastage. 10% Wastage Allowed 304 Mr Apostolakos’ evidence as to the wastage factor allowed in his calculation changed between examination-in-chief and cross-examination.196 He first said several times that 5% was the industry standard wastage factor normally allowed and referred to 5% as the wastage factor Contek allowed in correctly recalculating the volumes required after excluding the bathroom set-downs. That could not be verified because the tender take-offs were not in evidence. In cross-examination, Mr Apostolakos was taken to Contek’s pleading in reply that states: “and quoted for a common 10% wastage in using Deltacore panels”.197 When asked what this meant he said Contek allowed for a wastage factor of 10% when working with Deltacore and when 10% was questioned, said anywhere between 5 and 10% is an industry standard. When asked what percentage Contek had allowed he said he recollected 5% but later said it could have been 10% and honestly could not recall which.198 305 Mossop’s criticism of Mr Apostolakos’ evidence on this topic is overstated. The change in his evidence is explained by the passage of time. More importantly, a rerun of the volume calculations with a 10% and a 5% wastage factor for the total areas including bathroom set-downs by comparison to the total areas excluding the bathroom set-downs but no wastage, indicates Contek allowed a 10% wastage factor in preparing its take-off from the tender drawings. This should be inferred because the allowance with 10% wastage figure is almost the same as including 192 Exhibit A3.1 pages 173 to 175. 193 T197.36-198.3; T199.16-.26. 194 See [119] above. 195 T199.2-.22. 196 Written Submissions of the Respondent [71]. 197 Reply [3.1]. 198 T424.25-425-20. -- 58 of 106 -- [2024] SADC 1 57 the set-down pods as wastage.199 This is, of course, logical because the total area of the bathroom set-downs as a percentage of total topping slab area is 9.5%.200 306 It should therefore be accepted that Contek allowed 10% for wastage in accordance with its pleaded case in reply. Allowance for Joints, Infills or Fillings 307 Contek’s standard concrete allowance made no additional provision for joints, infills or fillings. Mr Apostolakos said in evidence that provision for gaps between the panels (joints) and gaps between the panels and steel or voids (infills) was included in wastage and as an industry standard for every 100m3, 5m3 should be allowed to fill gaps and joints in Deltacore floors. In any event, Contek allowed 10% wastage, as found above. 308 Mr Apostolakos’ evidence as to an industry standard was not directly challenged. However, the second concrete measure by Lifecare project quantity surveyors WT Partnership does not support Contek’s wastage allowance as a reasonable allowance for joints, infills and fillings of cored panels for this project. Their measure was 55.5m3 or about 16% of Contek’s original allowance both overall and for each floor.201 309 Contrary to Mr Apostolakos’ evidence, Mossop in closing submitted wastage should be for the exigencies of the project that cannot be precisely measured and added to the measured volume. Specifically, wastage is not for joints, infills and fillings or for thicker slabs that can and should be measured.202 310 Whilst this seems logical, it should be emphasised that what ultimately matters here is that the volumes allowed are fair and reasonable. The method of calculation is secondary. It is therefore not necessary to make a separate allowance for wastage over and above an allowance for joints, infills and fillings, if whatever allowance is made is fair and reasonable to complete the specified works including the joints, infills and fillings and wastage for exigencies. 311 In this case, where the measured volumes for joints, infills and fillings (55.5m3) materially exceed the wastage allowed by Contek (32m3), it would be fair and reasonable for Contek to have allowed for additional concrete for both the joints, infills and fillings and wastage including returns. On the evidence available, that further allowance should be for the measured volumes for the joints, infills and fillings (55.5m3). 199 That is 319.4m3 versus 318.0m3. 200 That is, 554.84m2 is 9.5% of 5855.2m2. 201 Exhibit A3.3 page 960 (aggregate for all floors). 202 Written Submissions of the Respondent [126]-[127]. -- 59 of 106 -- [2024] SADC 1 58 Allowance for 160mm Slabs 312 Self-evidently, Contek’s original concrete allowance did not make any provision for topping slabs thicker than 60mm. There was limited oral evidence about this unpleaded issue. In cross-examination, Mr Apostolakos agreed there were some areas where the topping slab was 160mm thick, saying they were external areas, but not big areas, that were shown on the drawings.203 No objection was taken to this line of cross-examination on the ground of relevance. Mr Mossop identified the relevant drawings showing the step down areas requiring an additional 100mm of topping slab over 60mm.204 Again, no objection was taken to this line of examination on the ground of relevance. 313 The same drawings are referenced in Mossop’s written submissions.205 It should be accepted these drawings show section details where the topping slab steps down from 160mm to 60mm from which a competent estimator would be able to measure the additional concrete required. 314 In closing, Mossop submits the total areas of 160mm thick slab are 269.28m2 and calculates a volume of 26.9m3 as the extra over the 60mm topping that should have been allowed in Contek’s concrete volumes.206 In doing so, Mossop relies on marked up drawings in Appendices 6 to 8 of its closing submissions as showing where the 160mm slabs are located on each of the floors. However, it has not proved its measurement of these areas and therefore the basis of its calculated volume. 315 WT Partnership’s measures do not support Mossop’s calculation. WT Partnership measured only 6.1m3 of additional 160mm thick topping slab on the ground floor in lieu of 60mm thick “as advised by Mossop”.207 This references Mossop’s email instruction:208 Also drawing GF 160 topping (see attached 95.80m3) will need to be removed from overall take-off. This is external area, helix was not used in this area. 316 WT Partnership’s measure should be preferred to Mossop’s inconsistent and unproven submission in the absence of any probative evidence explaining or contradicting WT Partnership’s measure. Allowance for 400mm Slabs 317 This issue was also not pleaded, and the only oral evidence that touched on it was given by Mr McFarlane when cross-examined by Contek’s counsel about the accuracy of survey measurement indicating a 400mm thick slab.209 His 203 T417.21-418.7. 204 T682.19-T683.27. 205 Written Submissions of the Respondent [112]-[114]. 206 Written Submissions of the Respondent [117]. 207 Exhibit A3.3 page 960 item 4. 208 Exhibit A3.3 page 957. 209 Written Submissions of the Respondent [120]-[122]. -- 60 of 106 -- [2024] SADC 1 59 evidence and the survey do not prove Helix mix was used for a 400mm thick slab as Mossop submits. It only proves slab thickness, not the constituent concrete mix. 318 Mossop’s claim is also contrary to Mr Apostolakos’ unchallenged evidence that the 400mm edge beams were poured separately using a different mix, not Helix. And Helix was not poured for the edge beams shown in blue on the first floor slab plan comprising part of Exhibit A14.210 319 Mossop’s submissions about 400mm thick topping slabs should be disregarded as unpleaded and unproven. Tender or Contract Drawings? 320 Contek relies on the tender drawings as the relevant starting point in confirming the reasonableness of its original concrete allowance. Mossop disagrees and relies on the contract drawings, although it contends there were minimal changes in the drawing revisions between tender and for construction affecting the concrete topping works. The difference is not material as shown by the concrete measures undertaken by WT Partnership and need not be considered further. Conclusion 321 Was Contek’s standard concrete allowance fair and reasonable? The answer is no and some adjustments should be made for the following reasons based on the findings made on this issue above. 322 First, it does not follow from Mossop’s acceptance of the credit given for the superseded concrete that Contek’s original allowance is objectively fair and reasonable. 323 However, seemingly more persuasive is the December 2018 measure from the engineering drawings made by WT Partnership. It was some 5% less than Contek’s original allowance overall by almost 18m3 (22m3 less for the ground floor and some 2m3 over but within tolerance for each of the first and second floors). This is all the more so given the inclusion in WT Partnership’s measure of allowances for joints, infills, fillings and 160mm thick concrete. 324 Whilst weight should be given to WT Partnership’s measure as reliable and cogent evidence of the required concrete, their measure for the ground floor (net of bathroom set-downs) is insufficient for a 60mm thick slab calculated on the proven net area: that is, 126m3/2,275.5m2 = 55.4mm. The area from which WT Partnership’s measure is derived is some 70% of the proven net area. The difference is not explained on the evidence, but it reflects adversely on the reasonableness of WT Partnership’s measure for the ground floor, and perhaps Contek’s original allowance. 210 T210.8-.30. -- 61 of 106 -- [2024] SADC 1 60 325 By contrast, WT Partnership’s measure provides more than sufficient cover for the first and second floors based on the proven net areas of the topping slabs. 326 WT Partnership’s total measured volumes do not resolve this issue. That is because its measure does not support Contek’s wastage allowance as a reasonable allowance for the measured joints, infills and fillings for this project. In this case, it would be fair and reasonable for Contek to have allowed for additional concrete for both the joints, infills and fillings and wastage including returns. 327 On the evidence available, further allowance should have been made for the measured volumes for the joints, infills and fillings (55.5m3). Contek’s wastage allowance of 10% (32m3) would then be fair and reasonable for the exigencies of the project including returns (20.7m3). Issue 5: What is a fair and reasonable measure for any additional concrete? Consideration and Conclusion 328 It should be accepted that additional Helix concrete was required due to ‘inconsistencies’ in the Deltacore floor. These ‘inconsistencies’ involved significant variation in the levels of Deltacore floor panels, both between panels and within a single panel, requiring additional concrete in lower areas so the higher areas would meet the 60mm specification and unexpected ‘gaps’ and ‘voids’ created by the uneven Deltacore floor panels. 329 Contrary to Mossop’s submissions, the Alexander Symonds survey and derived average slab thickness is not the ‘fullest and best’ evidence of the additional concrete required. Whilst the survey results are an accurate measurement of floor thickness at the locations measured, the derived average slab thicknesses are only an “educated approximation” due to material limitations in the survey methodology. An assessment made on average slab thickness is not the ‘fullest and best’ measure available and alone takes no account of the unquantifiable volume of additional concrete required for unexpected ‘gaps’ and ‘voids’ created by the uneven Deltacore floor panels. 330 The ‘fullest and best’ evidence of the additional concrete required is the volume of concrete supplied to site as proven by the Hanson delivery dockets (550.3m3) less a fair and reasonable allowance for the volume of standard concrete measured by the contract drawings. In the circumstances found on the evidence overall, Contek’s allowance for standard concrete should be increased to include the volumes for joints, infills and fillings (55.5m3) measured by the project quantity surveyors WT Partnership. 331 The following Table 9 sets out the fair and reasonable valuation of the additional volumes of Helix concrete supplied that should be allowed in lieu of the volumes assessed by Mossop. -- 62 of 106 -- [2024] SADC 1 61 Table 9 Description V2 - Ground Floor (m3) V6 - First Floor (m3) V8 – Second Floor (m3) Total (m3) Claimed supply Helix 241.70 183.40 143.50 568.60 Less over-claim (0) (12.20) (6.10) (18.30) Adjusted supply 241.70 171.20 137.40 550.30 Less standard concrete (148.00) (111.24) (92.22) (351.46) Less extra for joints (18.00) (12.10) (10.50) (40.60) Less extra for infills (4.50) (2.20) (.40) (7.10) Less extra for fillings (.60) (3.50) (3.70) (7.80) Less extra for 160mm (6.10) (6.10) Adj standard concrete (177.20) (129.04) (106.82) (413.06) Additional concrete 64.50 42.16 30.58 137.24 332 The values of these volumes using the undisputed price of $301/m3 for Helix concrete and $162/m3 for standard concrete are set out in Table 10 below. Table 10 Description V2 - Ground Floor ($) V6 - First Floor ($) V8 – Second Floor ($) Total ($) Adjusted supply Helix $72,751.70 $51,531.20 $41,357.40 $165,640.30 Less Adj standard concrete ($28,706.40) ($20,904.48) ($17,304.84) ($66,915.72) Additional concrete $44,045.30 $30,626.72 $24,052.56 $98,724.58 333 The volumes set out in Table 9 above increase the concrete pumping, pump hire and administration fees that should be allowed in favour of Contek. Therefore, further adjustments for concrete pumping, pump hire and administration as claimed in concrete variation claims V2, V6 and V8 should be allowed in favour of Contek, the undisputed credit for the supply of reinforcement and labour taken into account and the assessed amount deducted to calculate the outstanding amount of each of the concrete variation claims as set out Table 11 below. -- 63 of 106 -- [2024] SADC 1 62 Table 11 Description V2 - Ground Floor ($) V6 - First Floor ($) V8 – Second Floor ($) Total ($) Additional concrete $44,045.30 $30,626.72 $24,052.56 $98,724.58 Testing $ 400.00 $ 400.00 $ 400.00 $ 1,200.00 Concrete Pumping Additional Pumping $ 516.00 $ 337.28 $ 244.64 $ 1,097.92 Pump Hire (hours) $ 800.00 $ 400.00 $ 200.00 $ 1,400.00 $ 1,316.00 $ 737.28 $ 444.64 $ 2,497.92 Reinforcement Credit Supply -$ 9,592.00 -$ 8,055.00 -$ 7,271.00 -$24,918.00 Credit Labour -$ 6,640.00 -$ 5,016.00 -$ 4,488.00 -$16,144.00 -$16,232.00 -$13,071.00 -$11,759.00 -$41,062.00 Total Variation Claim $29,529.30 $18,693.00 $13,138.20 $61,360.50 Admin 5% $ 1,476.47 $ 934.65 $ 656.91 $ 3,068.03 Total ex GST $31,005.77 $19,627.65 $13,795.11 $64,428.53 Less assessed and paid ex GST - $ 4,977.00 -$13,250.59 -$ 5,545.76 -$23,773.35 Total payable ex GST $26,028.77 $ 6,377.06 $ 8,249.35 $40,655.18 GST $ 2,602.87 $ 637.71 $ 824.94 $ 4,065.52 Total payable inc GST $28,631.64 $ 7,014.77 $ 9,074. 29 $44,720.69 PART E: LIFECARE PROJECT – TOPIC 4 - EXTRA STEEL The Dispute – $27,007.66 ex GST211 The Variation Claims 334 Mossop disputes two variation claims (V7 and V9) made by Contek for additional materials (steel reinforcing) and labour for the first and second floors for design changes to aspects of the edges of the concrete slabs as shown in the relevant structural drawings: • First Floor Slab Plan 18090-S04 (S04) • Second Floor Slab Plan 18090-S05 (S05) • Structural Details (sheet 2) 18090-S23 (S23) 335 The first and key change concerns the planter box edge of the concrete slabs on each of the first and second floors shown in Section 20 on drawing S23. 336 The second change concerns Section X, the detail of the section through the western edge of the rear balcony212 on each of the first and second floors shown on drawings S04 and S05 respectively. The third change concerns the Section Z detail 211 $29,708.43 inc GST. 212 Located between gridlines 07 and 08 and F to D. -- 64 of 106 -- [2024] SADC 1 63 on the northern edge of the same balcony on each of the first and second floors on the same drawings. 337 V7 concerns the first floor.213 V9 concerns the second floor.214 They are for the same value because the changes to the reinforcing design were the same for each floor. Both are dated 17 May 2017, claiming $8,563.50 for the additional steel reinforcing and $4,800.00 for additional labour to place and fix six tonnes of reinforcing at $800/tonne. With a 5% administration fee, the total claimed per variation is $14,031.68 plus GST of $1,403.17. Together they total $28,063.36 plus GST of $2,806.34. 338 Both were claimed in Contek’s May 2017 Payment Claim. Mossop’s Assessment 339 Mossop’s May 2017 Payment Schedule shows that in assessing the May 2017 Payment Claim, these variation claims (among others) were neither rejected nor approved and recorded as “withheld - disputed via email and ongoing.”215 340 Mossop’s August 2017 Payment Schedule recorded both claims as wholly rejected on assessment.216 However, the September 2017 Payment Schedule217 records both as having been reviewed and further information and justification sought from Contek, including the reinforcing allowance made in Contek’s tender. 341 In response to Mossop’s request for further information and justification, on 29 September 2017 Contek provided Mossop support for these variation claims in the form of the documents supplied to Contek by its third-party supplier, OneSteel Reinforcing Pty Ltd218 (OneSteel) for the changes made to its supply contract with Contek for the reinforcing materials on-supplied to Mossop for the Lifecare Project.219 342 The OneSteel documents comprised two variation claims of identical value dated 24 February 2017, both raised as “VO17” for the “Revised Planter Edge Slab Section 20/23” and “Detail X Dm S04-03” changes to the first220 and second floor slabs221 for the Lifecare Project. Both referenced the quoted and revised drawings for the structural details applicable to both floors (S23) and (incorrectly) referenced the first and second floor slab drawings (S04 and S05 respectively). Despite these errors, it is clear that OneSteel claimed a variation of its supply 213 Exhibit A4.1 page 11. 214 Exhibit A4.1 page 12. It is accepted that V9 incorrectly references the drawing for the first floor slab but is to be understood as referring to the drawing for the second floor slab, revision 3. 215 Exhibit A2 page 55. 216 Exhibit A2 page 82. 217 Exhibit A2 page 86. 218 Now InfraBuild Construction Solutions Pty Ltd. 219 Exhibit A4.1 pages 18-22. 220 Exhibit A4.1 pages 19-20. 221 Exhibit A4.1 pages 21-22. -- 65 of 106 -- [2024] SADC 1 64 contract with Contek for reinforcing for each of the first and second floor slabs referencing the relevant drawings (S23, S04 and S05). 343 The increase to the OneSteel contract price claimed per variation was $8,561.00 ex GST for additional reinforcing materials plus a service and an administration charge. Each variation included a materials take-off itemising the quantity and value of the additional reinforcing by product and remarks indicating the relevant design change and the relevant drawing. 344 It is evident the Contek variation claims were based on the OneSteel variations forwarded to Mossop, despite a $2.50 difference in price per variation. Indeed, the Contek variations make the same error as OneSteel in referencing the wrong drawing number for the Section X detail.222 345 After reviewing the OneSteel variations, Mossop assessed and approved the Contek variations but only to a value of $162.37 ex GST per claim223 for “changes to reinforcing associated with drawing Rev 02.”224 It is apparent from the OneSteel variations225 that Mossop only valued the additional reinforcing materials and labour for the change to Detail X.226 The approved value was added to the Subcontract Sum in subsequent Payment Schedules.227 346 Contek continued to press the rejected component of these variation claims by email. 347 In February 2018, Mossop advised Contek that it had reviewed the Subcontract transmittal and the agreed scope of works referenced Revision 01 of drawing S23 (not Revision 00), so there was no change to the scope of works under the contract.228 Contek immediately responded claiming that any revision made after the tender drawings were issued was a variation because they were the basis of its tender price and Contek had not been advised of any changes to the drawings or given any opportunity to adjust its tender price before contract.229 348 In December 2020, Mossop reassessed these variations again on the basis that Contek was entitled to additional reinforcing for the changed Section X and Z230 Detail for the balcony on the first floor only. The additional value assessed was $365.48 ex GST.231 Yet Section Z is not the basis of the variation claims still pressed by Contek. Further, Mossop’s assessment purports to be made on the basis of the OneSteel variation claim values but the figures used for ‘value’ appear from 222 Drawing S04:03 cross-referenced Drawing S05:03 showing Section X revised detail. 223 Exhibit A2 page 108. 224 Exhibit A2 page 175. 225 Exhibit A4.2, pages 312, 321 and 322. 226 The detail of the materials in Mossop’s summary is the same as the materials in OneSteel’s VO17 for Detail X. 227 Exhibit A2 page 175. 228 Exhibit A4.1 page 35. 229 Ibid page 168. 230 Accepting that the reference to Y should have been Z. 231 $402.03 inc GST. -- 66 of 106 -- [2024] SADC 1 65 the extensions of the figures used by OneSteel to be ‘tonnages’ not prices. In any event, this further allowance by Mossop was not added to the Subcontract Sum in any Payment Schedule and not paid. It was, however, conceded at trial that $527.85 ex GST should be added to the Subcontract Sum per variation, leaving $13,503.83 ex GST in dispute per variation.232 349 This is the basis upon which the Court has proceeded to determine the dispute between the parties over these variation claims. The Lifecare Subcontract 350 The Lifecare subcontract was in writing and formed on execution. Mr Apostolakos executed it for Contek on 10 October 2016 and Mossop’s Project Manager, Mr Orlovic, executed it on 26 October 2016 for Mossop.233 Mr Orlovic was also the named Subcontract Superintendent. Contek’s contention to the effect that a binding agreement was made earlier should be rejected. 351 The subcontract terms expressly provide the parties’ agreement for Contek to supply materials and perform the concrete works in accordance with the written terms and conditions of the subcontract including Appendix D - Contract Documentation (Appendix D) in consideration for payment by Mossop of a fixed lump sum price of $1,092,980.00 ex GST.234 Appendix D expressly refers to the first revision of structural drawings issued on 6 September 2016, Revision 01 (the Contract Drawings).235 352 Whilst the works were completed on subsequent revisions of the structural drawings, the dispute over the extra steel variation claims primarily concerns design changes in the Contract Drawings from the previous revision of the structural drawings issued on 18 August 2016, Revision 00 (the Tender Drawings). 353 Execution followed a formal tender process involving dealings between Mr Apostolakos for Contek and Mr Barone, the Project Estimator for Mossop, that led to an accord being reached on 29 September 2016 as to the fixed lump sum price for the proposed concrete works. The subcontract price was struck on the basis of the Tender Drawings. Both the parties’ accord as to price and execution of the subcontract occurred after the Contract Drawings had been issued to Mossop, yet they were not sent to Contek. A subsequent revision of the structural drawings was only sent to Contek after execution of the subcontract. It is, however, the Contract Drawings that contain the primary variation in contention requiring extra steel reinforcing to strengthen to the tie between the balconies and the first and second floor slabs. 232 Written Submission of the Respondent [1] Table 1. 233 The execution copy comprises Exhibit A1 pages 182 to 224. 234 Exhibit A1 page 182, Formal Agreement, page 188 Part B – Subcontract Conditions, clause 2.1. 235 Exhibit A1 pages 213-214. -- 67 of 106 -- [2024] SADC 1 66 The Parties’ Contentions 354 The foundation of Contek’s case is that there was a mistake made in Appendix D of the executed subcontract listing the Contract Drawings instead of the Tender Drawings in circumstances where, following a formal tender process and negotiation of a revised fixed lump sum contract price, the continuing and intended basis of contract was the scope of works shown in the Tender Drawings as varied by some minor additional (unrelated) works. The alleged intentions of Mr Apostolakos for Contek and Messrs Barone and Orlovic for Mossop are relied on. 355 Contek’s primary claim is for rectification of Appendix D of the subcontract on the basis a common mistake was made as to the listed structural drawings. In the alternative, Contek seeks damages in the amount of the value of the variation works carried out by reason of Mossop’s misleading and deceptive conduct in breach of s 18 of the Australian Consumer Law236 for its silence in not identifying to Contek the steel variation works made in the Contract Drawings. If Mossop was not mistaken about the structural drawings referenced in Appendix D forming the intended basis of contract, then its silence gave rise to an active misrepresentation in circumstances where the subcontract price was negotiated in a formal tender process on the basis of the Tender Drawings and some minor additional (unrelated) works. 356 Mossop submits in answer to Contek’s claims that there can be no mistake as to the terms of the Lifecare subcontract. First, there were multiple express references to the Contract Drawings in Appendix D. Appendix D was provided to Contek twice (with the draft and the execution copies of the Subcontract terms) and carelessly read by Mr Apostolakos on each occasion. Secondly, the subcontract terms as to the listed drawings were clear from Appendix D and did not change just because Contek did not have those drawings until after Mr Apostolakos had executed the subcontract. Appendix D notified Contek of the relevant changes to the scope of works. Thirdly, Mossop could not be mistaken because it created Appendix D expressly referring to the Contract Drawings. Fourthly, Mr Barone did not have actual or ostensible authority to bind Mossop and therefore did not accept Mr Apostolakos’ offer by his 29 September email (although it is accepted that he had authority to negotiate the subcontract terms). Further, the subcontract terms bar the claim. 357 In the further alternative, Contek claims Mossop’s reliance on the reference to the Contract Drawings in Appendix D in all the circumstances would constitute unconscionable conduct within the meaning of ss 20 and 21 of the Australian Consumer Law. 237 However, these claims were not agitated at trial by Contek. Accordingly, the basis upon which Contek would have the Court find that Mossop’s conduct was not in good conscience and warrants a grant of relief in the further alternative to its rectification and misrepresentation claims was not made 236 Comprising Schedule 2 of the Competition and Consumer Act 2010 (Cth). 237 Claim [3.33]-[3.35]. -- 68 of 106 -- [2024] SADC 1 67 out, particularly bearing in mind that ss 20 and 21 are alternatives, s 20 only applying if s 21 does not. It is therefore unnecessary to consider these claims. 358 For completeness, Mossop’s pleaded reliance on the warranties in clauses 19.1.2238 and 19.1.7239 of the subcontract conditions should be mentioned.240 Since Mossop did not agitate at trial a defence based on these terms of the subcontract, it is inappropriate and unnecessary to deal with these pleas. Their relevance in defeating any of Contek’s claims is in any event not apparent. The Issues 359 Resolution of the parties’ disputes about Contek’s variation claims V7 and V9 involves consideration of the following issues. 1. Should the Lifecare subcontract be rectified to list the Tender Drawings in Schedule D? 2. In the alternative, did Mossop mislead or deceive Contek about the scope of work that formed the basis of the subcontract between the parties? 3. If yes to either of these questions, was there any material change between the reinforcing materials and labour required between the Tender and Contract Drawings? 4. If so, what is the fair and reasonable value of the variations claimed? 5. In any event, are these variation claims contractually barred? Issue 1: Should the Lifecare subcontract be rectified? Relevant Legal Principles 360 Since it is the application of the relevant legal principles in dispute, not the relevant legal principles, they may be briefly stated as follows.241 361 Rectification is a remedy concerned with a mistake as to an aspect of what is recorded in a written instrument and the conscience of the parties.242 362 The purpose of the equitable remedy of rectification is to make a written instrument conform to the ‘true agreement’ of the parties where the writing by common mistake fails to express their agreement accurately.243 The ‘true agreement’ may be manifested in a concluded antecedent agreement or the continuing concurrent intention of the parties up to the time the instrument was executed. Any common intention must be shown by admissible evidence and 238 To the effect that all subcontract documents have been examined including drawings. 239 To the effect of satisfaction that all prices in Contek’s tenders cover the costs of performing the subcontract works. 240 Defence [3.2] and [3.3]. 241 T791.3-.8. 242 Simic v NSW Land and Housing Corporation (Simic) (2016) 260 CLR 85 at [48] per Kiefel J. 243 Ibid at [103] per Gageler, Nettle and Gordon JJ citing Maralinga Pty Ltd v Major Enterprises Pty Ltd (Maralinga) (1973) 128 CLR 336 at 350. -- 69 of 106 -- [2024] SADC 1 68 proved to a high standard.244 Otherwise the “hypothesis arising from execution of the written instrument, namely, that it is the true agreement of the parties” cannot be displaced.245 363 It is incumbent on the applicant to show precisely the form to which the agreement should conform. 364 It is necessary to show the actual intention of each of the parties. Whilst often referred to as the ‘subjective’ intention of the parties, such intention must be objectively apparent from the words and conduct of each party. That is:246 [a] court, in determining whether the burden of proof is discharged, may be said to view the evidence of intention objectively, in the sense that it does not merely accept what a party says was in his or her mind, but instead considers and weighs admissible evidence probative of intention. 365 Proof of a party’s undisclosed intention in the course of negotiations is not sufficient. Where the parties do not express themselves in terms of their intention in contractual negotiations, it will be necessary to prove some manifestation of their intentions from their words or conduct as the basis for inferring the requisite common intention.247 366 Whilst it is settled that an antecedent agreement is not essential to the grant of relief by way of rectification, the absence of an outward expression of accord may be relevant to whether the necessary burden of proof has been discharged.248 The Evidence Some General Observations 367 Ultimately, the parties’ common intention to contract on the basis of the Tender Drawings was clearly expressed in an email exchange in which an accord was reached between the parties as to the revised subcontract price for a specified scope of works in a formal tender process. 368 This was so despite there being a number of evidentiary gaps about potentially relevant matters. 369 For example, there was no evidence about the genesis of Appendix D identifying different structural drawings to those forming the basis of tender and negotiations of the subcontract price, or why the Contract Drawings issued by PT Design to Mossop were not ever circulated and why a subsequent revision of 244 Ibid at [41] per Kiefel J. 245 Maralinga ibid at 350-351. 246 Simic at [42] per Kiefel J citing Australasian Performing Right Association Ltd v Austarama Television Pty Ltd [1972] 2 NSWLR 467. 247 Ibid at [43]. 248 Ibid at [45] per Kiefel J. -- 70 of 106 -- [2024] SADC 1 69 drawings was not circulated until after Mr Apostolakos had executed the subcontract. 370 Moreover, neither Mr Barone, Mossop’s Estimator, nor Mr Zilic, Mossop’s Contract Administrator, gave evidence at trial about relevant matters and Mr Orlovic, who did give evidence, was not asked any questions by either party on this topic. 371 Nonetheless there was documentary evidence clearly showing how the subcontract price was struck for the scope of works based on the Tender Drawings in a formal tender process. Key was an email exchange on 29 September 2016 between Mr Apostolakos for Contek and Mr Barone for Mossop which was copied to both Mr Orlovic and Mr Zilic. Mr Orlovic then arranged execution of the subcontract by Mr Apostolakos for Contek and later executed it for Mossop. Basis of the Subcontract Price 372 The agreed subcontract price was Contek’s tender price of $1,075,800.00 ex GST,249 as varied by the price for some minor additional (unrelated) works less a discount.250 373 Contek’s tender price was based on the Tender Drawings made available to invited tenderers for download from an on-line collaboration platform known as ‘BidContender’. Mossop’s invitation to tender was in evidence in printed form and identified Mr Barone as Mossop’s contact and stated that all tender inquiries should be directed to him. 251 Mossop formally admitted Mr Barone’s authority to negotiate the subcontract terms. 374 Contek downloaded and printed all the tender documents on 31 August 2016.252 These were the only drawings made available on ‘BidContender’ during the tender process and a subsequent revision to the Contract Drawings were first provided to Contek on 25 October 2016, after the accord between the parties had been reached on the subcontract scope of works and price and after Mr Apostolakos had executed the Lifecare subcontract. 375 Contek’s tender submission was dated 23 September 2016 and addressed to Mr Barone as per Mossop’s tender invitation. It was short, just over a page, and expressly referenced the Tender Drawings as the basis of the scope of works and materials priced in its tender.253 This is not contentious and was obvious to anyone from Mossop evaluating Contek’s tender submission and deciding whether to accept it or not. 249 Exhibit A1 page 3. 250 Exhibit A4.1 page 6aq. 251 Exhibit A4.1 page 6aa. 252 Ibid. 253 Exhibit A4.1 page 6ao. -- 71 of 106 -- [2024] SADC 1 70 Tender Evaluation Meeting 376 Mr Apostolakos of Contek was invited to a tender evaluation meeting held at Mossop’s office on 28 September 2016. Mr Barone attended for Mossop. Mr Orlovic was not at this meeting according to Mr Apostolakos254 and there is no evidence to indicate he was. 377 It is uncontentious that the Tender Drawings were the subject of discussions between Mr Apostolakos and Mr Barone at this meeting. The only factual dispute is whether the Contract Drawings were also present, reviewed and discussed at this meeting.255 378 Mr Apostolakos gave evidence that he took his tender file to this meeting. In it he had the tender invitation, Contek’s tender submission, a bound set of all the Tender Drawings downloaded and printed from BidContender and another set of his working drawings and calculations. The Tender Drawings had been downloaded into a software application ‘Bluebeam’ used in the construction industry to mark up plans and drawings and prepare take-offs and other calculations. Examples of his ‘Bluebeam’ drawings showing his later calculations of areas overlaid on the drawings were in evidence, although his tender file was not. Mr Barone had his own set of drawings. At Mr Barone’s suggestion they worked through the project, floor by floor, by reference to the drawings to ensure the scope of work allowed in Contek’s tender aligned with Mossop’s requirements.256 379 Mr Apostolakos recalled discussing some minor additional works and being asked by Mr Barone to cost those further works and revise his tender price. When shown the 29 September email exchange, he readily confirmed the scope of works described in it was as he recalled it.257 Mr Apostolakos gave uncontradicted evidence that they only discussed the Tender Drawings that he had used to come up with the tender price.258 380 It was also Mr Apostolakos’ uncontradicted evidence that before he executed the Lifecare subcontract he was not provided with any drawings other than the Tender Drawings before, during or after this meeting with Mr Barone.259 Indeed, as already stated, Mr Zilic did not send Mr Apostolakos a further revision of the structural drawings until 25 October 2016. 254 T68.32-.35. His evidence is contrary to Contek’s pleaded case at [3.10] and [3.11] of its Third Statement of Claim (FDN 66) and Mossop’s pleaded admission that was in its Third Defence and Counterclaim (FDN 67) and the Written Submissions of the Applicant at [61]. At trial Mossop accepted Mr Orlovic was not in attendance. 255 Mossop’s counsel conceded at trial that this part of Contek’s case was not formally challenged despite its formal plea that the Contract Drawings were also at the Tender evaluation meeting: Defence [3.11.1]; T501.7-.16. 256 T69.4-.30. 257 T78.25-79.6. 258 First Trial T150.27-.35. Second Trial T428.6-429.3. 259 First Trial T166.9-.12; 167.36-168.4. Second Trial T77.38-78.2; T79.18-.23. -- 72 of 106 -- [2024] SADC 1 71 381 Mossop’s pleaded contention that Mr Apostolakos knew about the Contract Drawings at the tender evaluation meeting where they were made available260 is not made out on the evidence. It should be accepted that only the Tender Drawings were tabled, reviewed and discussed at this meeting and the only variation to the proposed subcontract works discussed were the minor additional works that did not concern the variation to the reinforcing between the planter box edges and the first and second floor slabs. Revised Tender Price 382 The next day, 29 September 2016, Mr Apostolakos emailed261 Mr Barone about the minor additional works they had discussed at the tender evaluation meeting. He made some suggestions about how these additional works could be done and offered a price for each component of the minor additional works including a discount on the basis that Contek would complete the specified additional works at cost with no margin. 383 Contek’s revised pricing for the revised scope of works was completely transparent. The total revised tender price was simply the addition of the tender price he had quoted in Contek’s tender submission for the scope of works in the Tender Drawings and the price of the additional works less the discount. The revised scope of works was based on the Tender Drawings and only revised by the minor additional works. 384 Mr Barone responded just over an hour later by email,262 copying in Mossop’s Project Manager, Mr Orlovic, and Mossop’s Contract Administrator, Mr Zilic. The commercial necessity for the inclusion of the Project Manager and Contract Administrator in this email by this stage is obvious. It was important for all of them to understand the basis of the subcontract price given the scope of works the subject of the price was fundamental to the intended basis of contract between Contek and Mossop and the next steps once price was agreed were for execution of the formal subcontract and works to commence on site. 385 Mr Barone described Mossop’s intention to engage Contek to undertake the concrete works for the Lifecare project in the following terms:263 Further to your quote T-0904 Rev1 dated 23 September 2016 and additions listed below, I am pleased to confirm our intent to engage Contek to undertake the Concrete Works package for this project for the sum of $1,092,180 + GST as made up below, based on the attached scope of work, Mossop Construction + Interior Contract conditions, and Construction Program and tender evaluation meeting held at our office on Wednesday 28 September 2016. A full set of For Construction documents will be issued via Bidcontender. A formal subcontract agreement will be forwarded shortly. 260 Defence [3.18.2]. 261 Exhibit A4.1 page 6aq. 262 Exhibit A1 page 6-7. 263 Ibid. Emphasis supplied. -- 73 of 106 -- [2024] SADC 1 72 Please contact Harry Orlovic on … to confirm commencement dated on site. • Tender Amount (T-0904Rev1.23.09.16) $1,075,800 + GST • Supply and fix formwork capping beam $6,380 + GST • Additional cost 2xP4 to P1 pads $3,850 + GST • Supply and place leanmix to capping beam $5,900 + GST • Additional formwork to capping beam (form second side to south beam) $3,250 + GST • Subtotal $1,095,180 + GST • Less Discount -$3,000 + GST _______________ Revised Total $1,092,180 + GST 386 Self-evidently, the listed additions do not concern the variation to the steel reinforcing in the planter box edges for the first and second floor slabs. 387 Mr Barone’s email attached a number of documents. The first was “Appendix C – Scope of Works”264 dated 28 September 2016 (the date of the tender evaluation meeting). It described the concrete works without reference to any drawings or specifications. Some of its text was in bold describing the minor additional works listed in the email and expressly referred to the discussion in this meeting.265 The other documents were the “20160610” Revised Subcontract Agreement and Revision 2 of the Construction Program. Appendix C in the subcontract was blank: “TBA.” It would have been understood by all that the first document would be inserted into the blank section of the subcontract. 388 None of the drawings or plans were attached. The Common Mistake 389 Whilst Mr Barone’s 29 September email expressly referred to an intention to contract based on the attached scope of works and other contract documents, it more plainly expressed an intention on the part of Mossop to contract on the scope of works in the Tender Drawings for the “Tender Amount” as revised by the discounted quoted prices for the listed minor additional works offered in Mr Apostolakos’ earlier email. 390 It should be inferred from what had transpired during the formal tender process that all of the parties to this email exchange shared the intention that the attached “Appendix C - Scope of Works” and other contract documents (including Appendix D) would accurately reflect the same scope of works that was the basis of the revised tender price: that is, the scope of work specified in the Tender Drawings plus the specified minor additional (unrelated) works discussed at the tender evaluation meeting, listed in the email and shown in bold in Appendix C. Indeed, it would have been incongruous for the attachments to Mr Barone’s email to have been intended to reflect a different scope of works to the one expressly priced in Mr Barone’s email exchange with Mr Apostolakos. Further, it would 264 Exhibit A4.1 page 107. 265 The 4th, 5th and final dot points. -- 74 of 106 -- [2024] SADC 1 73 have been anomalous for anyone involved from Mossop who considered otherwise not to have said so expressly and no one did say anything about the contractual scope of work being different from the expressed basis of the negotiated subcontract price. 391 Certainly, Mr Barone knew that Contek’s revised tender price was based on the Tender Drawings because he was the named contact for tender process and the named recipient of Contek’s tender submission, had met with Mr Apostolakos to evaluate Contek’s tender and exchanged emails about revising the tender scope of works and price for the specified minor additional works that did not concern the variation to the steel reinforcing in the planter box edges for the first and second floor slabs. 392 Mr Apostolakos knew, of course, that Contek’s revised tender price was based on the Tender Drawings because he had prepared and expressly qualified Contek’s initial tender price as based on the Tender Drawings and did not depart from that basis in negotiating the revised tender price for the revised scope of works or subsequently. 393 Mr Zilic did not give evidence at the trial and Mr Orlovic’s evidence did not touch on this topic directly, although he recalled the extra steel variations.266 However, it should be accepted that Mr Orlovic, as Mossop’s Project Manager, and Mr Zilic, as the Contract Administrator, also knew Contek’s revised subcontract price was struck on the basis of the Tender Drawings since they were both copied into the relevant email exchange and the scope of works for Contek’s revised pricing was wholly transparent. By reason of their positions and key roles on the Lifecare Project, it should also be inferred Mr Zilic and Mr Orlovic knew about the formal tender process that led to Contek quoting a revised price based on the Tender Drawings and some minor additional works because the Tender Drawings were the only ones made available to tenderers. 394 Notably, there is no oral evidence and only scant documentary evidence about how the change from the Tender to Contract Drawings and subsequent revisions came about and when Mossop received them. Revised structural drawings were sent by email from the project architect to Mr Jathin Balan of Mossop on 6 September 2016.267 Neither the project architect nor Mr Balan gave evidence. The message stated that the revised structural drawings incorporate value management revisions discussed last Friday and complete the for construction drawings. Nothing further is known about this process or how (if at all) it bears on the planter box edge design change for the first and second floor slabs. 395 Mr Barone was copied into this email and he forwarded it within Mossop with an instruction to “print, split up, file etc”. 266 T737.2-.12; T738.11-T739.4. 267 Exhibit A3.1 pages 15c-15ac. -- 75 of 106 -- [2024] SADC 1 74 396 It is apparent from a subsequent internal email268 within Mossop (also copied to Mr Orlovic) that Mr Barone reviewed these drawings but only identified changes impacting cost on the footing layout plan on Revision 04 of drawing S02, a different drawing to the slab plans and structural details in contention over the extra steel variations. The two P4 pad footings had become larger P1 footings that he identified as an unbudgeted additional cost of $3,900.00 plus GST. 397 Notably, in his review of the Contract Drawings, Mr Barone did not identify the change on Revision 01 of drawing S23 to add N16 reinforcing bars in lieu of reinforcing mesh in the planter box edges of the first and second floor slabs, the subject of Contek’s extra steel variation claims. 398 This email explains why the extra steel reinforcing changes to the planter box edges were not identified by the Mossop representatives as a variation to Contek’s tender price based on the Tender Drawings as discussed at the tender evaluation meeting and the subject of the 29 September 2016 email exchange. Only the identified changes impacting cost were expressly listed in the email and marked up in “Appendix C – Scope of Works.” 399 As stated, there is no evidence about the updating of Appendix D or why the Contract Drawings were not circulated, and a subsequent revision of the Contract Drawings only circulated on 25 October 2016 although the Contract Drawings had been prepared on 6 September 2016. 400 Ultimately, all the evidence suggests Mr Barone did not appreciate that Appendix D specified a different scope of works than the basis of the revised scope of works he had negotiated with Mr Apostolakos because a new revision of structural drawings had been issued, that is the Contract Drawings. There is no reason on the evidence to think either Mr Orlovic or Mr Zilic had a different appreciation, noting Mr Orlovic was copied into Mr Barone’s earlier email. 401 It therefore should not be accepted as Mossop submits that because the multiple references in Appendix D to the Contract Drawings were express there was no common mistake or because Mossop (allegedly) created Appendix D and Mossop had been issued the Contract Drawings that Mossop was not mistaken. 402 Mossop’s submissions that Mr Apostolakos knew a full set of the Contract Drawings was available at Mossop’s head office that he could have gone and inspected or that he was aware of Contek’s contractual obligations with regard to discrepancies in documents are not relevant and no answer to Contek’s claim for rectification. 403 Nor is it an answer that price is only one element of the contract and not all of the contract.269 Price and the scope of works to be performed for the agreed price were inextricably linked in the accord reached between the parties and wholly 268 Exhibit A3.1 page 15ad. 269 Balance of Written Submissions of the Respondent [98]. -- 76 of 106 -- [2024] SADC 1 75 transparent in this case. The parties’ words and conduct manifested a clear intention to contract on the basis of the Tender Drawings as revised by only the minor additional works. 404 It should also be accepted that Mr Apostolakos was truly mistaken and not careless in reading Appendix D. The references to the Contract Drawings were not obvious from the nearly 100 pages of annexures to Mr Barone’s email. By first referring to and attaching “Appendix C – Scope of Works,” Mr Barone focussed attention on it. It was important because it self-evidently contained and highlighted the revised scope of works discussed in the tender evaluation meeting. There were no changes in Appendix C reflecting any change to the reinforcing in the planter box edges of the first and second floor slabs. The subcontract followed (with a blank Appendix C) and then Appendix D,270 followed by further appendices and lastly the program. 405 Appendix D was in tabular form listing drawings (and other contract documents) with some 17 columns indicating successive issue dates. It was only 14 pages in length among the 100-odd pages. The structural drawings are listed on pages 5 and 6 and in the second and very last column drawings for S03 to S06, S11 and S20 to S23, the revision number is shown as “01”, as compared to revision “00” issued for tender. The column headings are not repeated on every page, and it is only on page 1 that the date “6/09/2016” is written vertically indicating that it was the latest issue. 406 It was in the circumstances not unreasonable for anyone reviewing these documents to overlook the references to revision “01” of the relevant structural drawings. 407 Ultimately, the compelling consideration is that the specification of this further revision of drawings in Appendix D was inconsistent with the negotiated basis of Contek’s tender and revised tender price, terms fundamental to the parties’ intention to contract as manifested by the parties’ words and conduct in striking the lump sum subcontract price for the scope of works in the Tender Drawings as revised only by the minor additional works. It should therefore be accepted that the specification in Appendix D of the Contract Drawings as the basis of contract was a mistake shared by all parties to the 29 September email exchange. 408 There is no basis in fact for finding only Mr Apostolakos was mistaken as to the scope of works the subject of the intended basis of contract. Unilateral Mistake 409 If it were to be considered that only Mr Apostolakos was mistaken about the subcontract scope of works specified in Appendix D, or that he made a different mistake from that of the Mossop representatives because they knew about the Contract Drawings and he did not, Contek’s submissions that the Court should 270 Exhibit A1 pages 136-148. -- 77 of 106 -- [2024] SADC 1 76 rectify the subcontract should still be accepted.271 It would be unconscionable for Mossop to deny that the subcontract scope of works was that reflected in the Tender Drawings as revised by the minor additional works and not rectify the references in Appendix D to the relevant structural drawings272 to refer to the Tender Drawings. Executed Subcontract 410 The next day, 30 September 2016, an execution copy of the Lifecare subcontract was sent to Contek under cover of a letter by Mr Orlovic, Mossop’s Project Manager, asking for it to be signed and returned to Mossop.273 Nothing else was said. On review of the documents, it would have been apparent that Appendix C of the subcontract had been completed and was in the form attached to Mr Barone’s email the previous day. Also included in the subcontract was Appendix D in the same form as attached to Mr Barone’s email, again expressly referring to the first revision to the structural (and other) drawings, that is the Contract and not the Tender Drawings. 411 The execution copy specified as the subcontract price the revised tender price the subject of the 29 September email exchange. 412 On the evidence, there is no reason to think that the parties’ intention to contract on the basis of the revised tender price for the scope of works in the Tender Drawings as revised by the specified additional works had changed, despite Appendix D again expressly referring to the Contract Drawings. Again, there is no basis in fact for finding only Mr Apostolakos was mistaken as to the intended basis of contract. 413 Mr Apostolakos signed the Lifecare Subcontract and dated it on 10 October 2016. Mr Orlovic signed for Mossop of 26 October 2016. The authority of Mr Orlovic as Mossop’s Project Manager to bind Mossop by executing the subcontract was not challenged. 414 Bearing in mind the 29 September email exchange and its context in the formal tender process for the concrete works that it finalised, it should be inferred that if Mr Apostolakos and Mr Orlovic had been asked at the time they executed their counterpart of the subcontract what scope of works was the basis of the negotiated revised subcontract price, they would have identified the scope of works in the Tender Drawings as varied by the minor additional works listed in Appendix C and not the Contract Drawings including the design changes to the reinforcing for the planter box edges for the first and second floor slabs. Again, it would have been incongruous for the subcontract to have been intended to reflect a different scope of works to the one expressly priced in Mr Barone’s 29 September email exchange with Mr Apostolakos. Further, it would have been anomalous for 271 Written Submissions of the Applicant [94]-[101]. 272 S04, S05 and S23 but not S02. 273 Exhibit A1 pages 108-181. -- 78 of 106 -- [2024] SADC 1 77 Mr Orlovic not to have said so expressly. Indeed, he again did not say anything about the contractual scope of works being different from the scope of works forming the basis of the revised tender amount and the agreed subcontract sum the subject of the accord reached in the 29 September email exchange. 415 That same day, Mr Apostolakos received an email from OneSteel confirming receipt of the Tender Drawings and verbally confirmed his order for supply.274 The minor additional works did not involve any additional steel reinforcing. His conduct was consistent with the basis on which he had negotiated Contek’s revised tender price and his evidence that he did not know that the subcontract documentation reflected a different scope of works than that discussed at the tender evaluation meeting based on the Tender Drawings.275 Issue of the Contract Drawings 416 Contek was not sent the Contract Drawings issued by PT Design on 6 September 2016. Why was not explained by Mossop. Mr Zilic of Mossop circulated a subsequent revision of all the drawings by email to many recipients, including Mr Apostolakos. He sent two emails. 276 The first sent on 24 October stated: “Please see attached updated drawings (Structural and Civil) and an up to date doc register. Please ensure you have the latest drawings compared to the doc register”. Since he forgot to attach the revised structural drawings to his email, he sent them the following day apologising in his second email for not attaching them. 417 Mossop concedes there was no transmission of the Contract Drawings or any drawings showing the changes to the steel reinforcing for the planter box edges for the first and second floor slabs before the revised drawings circulated on 25 October 2016, submitting that the factual dispute concerns whether the Contract Drawings were present and discussed at the tender evaluation meeting.277 418 It should be accepted that Mr Apostolakos first found out the structural drawings had been updated since tender and contract when he received Mr Zilic’s 25 October 2016 email, without realising they had been issued before contract, were identified in Appendix D to the executed Lifecare subcontract as the Contract Drawings and specified a design change to the reinforcing for the planter box edges for the first and second floor slabs. 419 It is evident that Mr Apostolakos’ mistaken belief continued to be more broadly shared by Mossop representatives until February 2018 when Mr Raptopoulos, Mossop’s then Contract Administrator, first raised as a basis for rejecting Contek’s variations claims that the contract scope of works had not changed because the Contract Drawing for Section 20 was S23:01, not S23:00.278 274 See reference in cutting schedules in Exhibit A4.2 to “verbal order Paul 29/9/16”. 275 T491.26-.31. 276 Exhibit A4.1 page 151. 277 T53.6-.17. 278 Ibid page 35. -- 79 of 106 -- [2024] SADC 1 78 It is telling that this basis of rejection was not raised by Mossop when it first received Contek’s variation claims V7 and V9 in May 2017. 420 Not unsurprisingly, Mr Apostolakos gave evidence that if he had been told the revised drawings were the basis of the subcontract scope of works, he would have analysed any changes and their impact on the price he had submitted that formed the basis of the agreed subcontract price279 and negotiated a higher subcontract price. Conclusion 421 The answer to the question as to whether the Lifecare subcontract should be rectified is yes. For the preceding reasons, the Lifecare subcontract should be rectified to list revision 00 of the relevant structural drawings S04, S05 and S23 in Appendix D to reflect the common intention of the parties as to the scope of works allowed in the agreed lump sum price negotiated during the formal tender process and the intended basis of contract. Issue 2: Did Mossop mislead Contek about the Contract Drawings? 422 Having found Contek’s rectification claim succeeds, it is not strictly necessary to determine the alternate basis upon which Contek presses its variation claims for extra steel. However, for completeness this claim is addressed briefly. 423 Contek pleads in the alternative a claim for misrepresentation by Mossop’s alleged silence in not identifying the design change to the reinforcing in the planter box edges in the Contract Drawings in the circumstances surrounding the negotiation of the Lifecare subcontract price on the basis of the Tender Drawings.280 Mossop denies the alleged representations281 give rise to a representation that the contract to be entered into was for a price reflecting the scope of works set out in the Tender Drawings. Mossop relies on what it says is expressly stated in the draft and execution contracts to the contrary, contending that all the evidence shows is Mr Apostolakos’ lack of care in reviewing the draft and execution versions of the subcontract. Not only did Mossop communicate the relevant changes (by the references to the Contract Drawings in Appendix D), Mossop submits it had no obligation to ensure that Mr Apostolakos read and understood what was plainly before him in the subcontract documents.282 424 Mossop’s denials should be rejected “in the light of all relevant circumstances constituted by acts, commissions, statements or silence” showing that there has been conduct which is or is likely to be misleading and deceptive,283 inadvertent or not. The alleged representation that the parties would be entering into a contract for a price reflecting the scope of works set out in the Tender 279 T86.24-.38. 280 Statement of Claim [3.27]-[3.32]. 281 Statement of Claim [3.11] as to the Tender Evaluations Meeting Representations and [3.15] as to the Contract Acceptance Representations. 282 Written Submissions of the Respondent [15]-[17] of Part 5. 283 Demagogue Pty Ltd v Ramensky (1992) 39 FCR 31 at 41 per Gummow J. -- 80 of 106 -- [2024] SADC 1 79 Drawings as varied by only the minor additional works is implicit in the parties’ dealings in negotiating the revised subcontract price as relied on by Contek and fully discussed earlier in these reasons on the issue of rectification. 425 The silence of the Mossop representatives (Messrs Orlovic, Barone and Zilic) in not disclosing a different scope of works in Contract Drawings as the intended basis of contract should be accepted as misleading and deceptive in all the circumstances, even if the silence was inadvertent. It was in the circumstances entirely reasonable for Mr Apostolakos to have expected any one of the Mossop representatives would have told him that the scope of works forming the basis of the negotiated subcontract price had changed in the contract documents if that were the case, particularly when only the minor additional works had been identified as a relevant variation to the scope of works in the Tender Drawings in reaching an accord on a revised subcontract price. 426 As already stated, Mr Apostolakos’ evidence that he did not appreciate there had been a further change to the scope of works, that he relied on the Tender Drawings as the basis of contract as varied by the minor additional works and would have repriced the works if told otherwise should be accepted on the issue of reliance. 427 The measure of Contek’s damages is the fair and reasonable value of its variation claims for extra steel. Issue 3: Was there any material change between the Tender and Contract Drawings? The Drawings 428 Drawing S11 is the first sheet of the building sections and shows the first and second floor slabs are to comprise Deltacore panels with 400mm deep concrete edge beams284 and refers to the floor slab plan drawings S04 and S05. 429 The floor slab plan drawings S04 and S05 show the Deltacore slab and 400mm edge beams (denoted as [400 SLAB]) and (surrounding the 400mm slabs) 175mm concrete edges (denoted as [175 SLAB]). These edges were referred to by the parties as the ‘planter box edges’. On some parts of the 175mm edges planter boxes are drawn in.285 430 The third note for all revisions of the floor slab plans provides: PROVIDE 60mm MINIMUM CONCRETE TOPPING, REINFORCED WITH SL72 FABRIC (TF) THROUGHOUT & CRACK CONTROL BARS AS INDICATED ON LAYOUTS, UNLESS NOTED OTHERWISE. 284 Save for one section on the southern side. 285 For example on the edges of the west facing rooms. -- 81 of 106 -- [2024] SADC 1 80 431 There are notes indicating throughout that the 400mm slab is to include reinforcing bars (denoted by “N16-200CTS”)286 in addition to the reinforcing mesh. 432 The structural details drawing S23 shows various typical details including, most relevantly, Section 20 noted as “showing typical connections at planter box on north sides for levels 1 & 2”. Changes to the Reinforcing 433 The various revisions of the drawings show the progressive changes made between tender and construction to the structural engineering design of the building to strengthen the reinforcing of both the 175mm planter box edges on the first and second floors and the connections between the planter box edges and 400mm edge beams into the Deltacore slab. 287 434 The key change in contention concerns the reinforcing of the planter box edging on the first and second floors introduced by a change to Section 20 on S23 in the Contract Drawings. Essentially, the Tender Drawings provided for the 175mm planter boxes slab edges to be reinforced with a single layer of “SL92 fabric” reinforcing mesh as distinct from bars.288 Revision 01 of drawing S23 issued on 6 September 2016 introduced a change to Section 20 to strengthen the connection between the planter box edge and the 400mm slab by replacing the reinforcing mesh with reinforcing bars (N16-200 CTS).289 435 Further changes were made to the Section 20 details by revision 02 of drawing S23 issued on 30 November 2016 to strengthen the connections between the planter box edge and the balcony and the Deltacore slab.290 436 Changes were also made to the reinforcing to the rear balcony on the first and second floors, to strengthen the connection between the 400mm concrete edge beam and the Deltacore slab by breaking out the Deltacore panels and tying in additional steel reinforcing bars: refer Sections X and Z details for the first291 and second floors292 on revision 03 of the slab plan drawings293 issued on 30 November 2016. 437 The change to Section 20 on drawing S23 introduced by the Contract Drawings is not a mere ‘clarification’ to the quantity of reinforcing bars required in the 175mm planter box edge that should have been apparent from the Tender Drawings as contended by Mossop. It is a clear change requiring additional 286 That is, reinforcing bars with a nominal diameter of 16mm spaced at 200mm. 287 T738.28-.38. 288 Refer Section 20 drawing S23:00 issued 18 August 2016 showing the typical connections at the planter box, Exhibit A4.1 page 5. 289 Exhibit A4.1 page 6c. 290 Exhibit A4.1 page 9. 291 Exhibit A4.1 page 7. 292 Exhibit A4.1 page 8. 293 S04 and S05. -- 82 of 106 -- [2024] SADC 1 81 reinforcing bars in lieu of reinforcing mesh. Therefore, Mossop’s submission that the revision 03 drawings introduced the only change (to Section X by introducing Section Z) should be rejected. Conclusion 438 The answer to the question as to whether there was any material change between the Tender and Contract Drawings is yes. There was a change to Section 20 on drawing S23 introduced by the Contract Drawings requiring additional reinforcing bars in lieu of reinforcing mesh on the ‘planter box edges’ of the first and second floor concrete slabs as well as the changes to the Sections X and Z details for the first and second floors on revision 03 of the slab plan drawings. Issue 4: What is the fair and reasonable value of the variation claimed? OneSteel Documents 439 Contek based its tender price in part on an estimate294 for the supply of reinforcing materials prepared by its third-party supplier, OneSteel, based on the Tender Drawings.295 It is evident from OneSteel’s estimate and the cutting schedules296 for the reinforcing actually supplied that preparation of its estimate involved OneSteel’s estimator reviewing and preparing a materials take-off from the Tender Drawings supplied in computer-aided design (CAD) software, although the workings for that take-off were not in evidence. 440 On about 29 September 2016, Contek placed a verbal order297 with OneSteel for steel reinforcing for the Lifecare Project and contracted with OneSteel for the supply of steel reinforcing on the scope and price of OneSteel’s estimate based on the Tender Drawings.298 441 Unknown to Contek at the time, OneSteel was also asked by Mossop to provide an estimate for the supply of reinforcing for the Lifecare project.299 In evidence, Mr Mossop explained Mossop priced its tender as builder to the owner in two ways: first, on the basis the concrete works would be done by a subcontractor and, secondly, on the basis that Mossop would do the concrete works in-house. He said this was “pretty much normal practice on concrete.”300 It is apparent this was done to ensure the most competitive price in circumstances where Mossop had been awarded the contract as builder after a value management process resulting in some significant revisions to the design and selection to achieve cost reductions required by the client. 294 Exhibit A4.2 pages 163-166. The cutting schedules for the reinforcing ultimately supplied comprise pages 168-310. 295 Ibid. The Tender Drawings are expressly specified. 296 Exhibit A4.2 pages 168-310. 297 Ibid. 298 Exhibit A4.2 page 152. 299 Exhibit A4.1 page 6ae-6an. 300 T646.17-.21. -- 83 of 106 -- [2024] SADC 1 82 442 Mossop, as an experienced builder, was therefore well aware of the estimating and supply process for steel reinforcing based on engineering drawings and material specifications. That is, in quoting to supply a job such as the Lifecare Project, the materials take-off would be done by the steel reinforcing supplier’s estimator from the relevant drawings and material specifications in a CAD program and would be relied on by whoever carried out the concreting works as the basis of the price and contract for the supply and installation of reinforcing materials. 443 Indeed, in evidence Mr Orlovic accepted that information from OneSteel would be a fair and reasonable basis upon which to assess the claimed variation,301 although assessment of these variations was removed from him as Subcontract Superintendent and taken over by head office.302 444 In addition to the documents supplied to Contek by OneSteel during the course of this dispute that were in evidence, OneSteel produced documents in answer to a subpoena issued by Mossop303 that were tendered at trial. The following matters are evident from the OneSteel subpoena documents that support the reasonableness of the value of Contek’s variation claims. 445 OneSteel progressively supplied steel reinforcing for the Lifecare project as shown in its cutting schedules.304 Each progressively numbered schedule specifies the reinforcing product supplied by colour, bar mark, product, number of, length and shape, referenced to an area of the works and a drawing (where supplied) or a notified change. The tonnage of each item and a total for all items per cutting schedule is recorded. 446 As the steel reinforcing was cut and deliveries made to site, OneSteel invoiced Contek progressively for the steel reinforcing supplied based on agreed progress claims less omissions and plus additions to the materials identified in its 30 September 2016 estimate. OneSteel305 invoices for the April306 and May 2017307 progress claims refer to four variations: “vo16”, “vo17”, “vo18” and “vo19”. 447 However, only OneSteel’s variations “vo17” and “vo18” were in evidence. 448 Variation “vo17”308 is dated 24 February 2017 and is for “additions” to the first floor slab309 described as “Revised Planter Edge Slab Section 20/S23” and “Detail X Dm S04-03”. It is self-evidently based on a take-off of the additional steel reinforcing required in lieu of the reinforcing fabric specified in the 301 T737.2-.12. 302 T737.29-.33. 303 Exhibit A4.2. 304 Exhibit A4.2 pages 168-310. 305 Now on InfraBuild letterhead. 306 Exhibit A4.2 page 321. 307 Exhibit A4.2page 322. 308 Exhibit A4.2 page 312. 309 Emphasis supplied. -- 84 of 106 -- [2024] SADC 1 83 superseded Tender Drawing S23:00 and for the change to Detail X. The additional total price was $7,414.27 plus an administration charge of $370.71, totalling $7,785.00 ex GST. 449 Variation “vo17” is identical to the OneSteel take-off used by Contek to prepare its variation claim that was sent to Mossop in September 2017 save for the values: therefore the totals are different. A total of $7,784.98 ex GST was rounded to $7,785.00 ex GST and invoiced on 27 April 2017310 and paid by Contek on 27 June 2017.311 450 Variation “vo18”312 is also dated 24 February 2017 and is a credit for the deletion of SL92 fabric from the “2nd floor slab”313 and “the planter edge slab Refer Sect20/S23-00” (and SWL 2 from the topping slab) in the amount of $7,271.00 ex GST.314 It was invoiced by OneSteel on 26 May 2017315 as a credit against the May 2017 progress claim. Payments of the total of that invoice were made by Contek on 4 and 10 July 2017.316 451 Contek passed the same credit on to Mossop in variation claim 8 dated 17 May 2017 as “credit supply reinforcement” for the change to use steel fibres in lieu of reinforcing mesh in the topping slab.317 No complaint was made about the reasonableness of the price for the reinforcing mesh that was the subject of credits that had the same genesis as the price for the additional reinforcing bars claimed in these variations. 452 From the relevant OneSteel invoices, it is apparent that variation “vo19” invoiced on 16 May 2017 is OneSteel’s claim for “additions” for the second floor slab. The same value is claimed as for the first floor, and the May progress claim aligns with the progress of the works from the first to the second floor slab as per the dates on the OneSteel cutting schedules and the “omissions” for the second floor slab in variation “vo18” invoiced on 26 May 2017. 453 It is apparent that the other claim for ‘omissions’ for the first floor is variation “vo16” invoiced by OneSteel as a credit on 27 April 2017. This is confirmed by the credit of $8,055.00 ex GST that Contek passed on to Mossop in variation claim 6 dated 17 May 2017 as “credit supply reinforcement” for the change to use steel fibres in lieu of mesh in the topping slab.318 310 ExhibitA4.2 page 321. 311 Exhibit A4.2 page 328. 312 Exhibit A4.2 page 311. 313 Emphasis supplied. 314 Exhibit A4.2 page 311. 315 Exhibit A4.2 page 322. 316 Exhibit A4.1 page 328. 317 Exhibit A2 page 210. 318 Exhibit A2 page-207. -- 85 of 106 -- [2024] SADC 1 84 Conclusion 454 The tonnage and prices claimed by Contek for these variations are fair and reasonable having regard to the OneSteel variations claims paid by Contek for the same materials. Issue 5: Are these variation claims contractually barred? Consideration 455 Mossop contended at trial that these variation claims were contractually barred because no variation notice was given in compliance with clause 24.5 of the Lifecare subcontract. Further, Mossop submits such notices are a pre-condition to any entitlement to claim the steel variations and such notices should have been pleaded by Contek.319 456 Contek disagrees, objects to Mossop raising an unpleaded defence at trial and contends that properly read, clause 24.5 does not operate as a contractual bar. It submits that the consequence of any failure to comply with clause 24.5 is expressly addressed by clause 24.11, imposing an obligation on the Subcontract Superintendent to value the variation claim fairly and reasonably in that event. 457 Contek’s contentions should be accepted. 458 Mossop should be confined to its pleaded case. Its pleaded defences do not include any contractual bar to claim for the steel variation claims, unlike its pleaded defence to Contek’s concrete variations claims (V2, V6 and V8). There is no basis for expressly or implicitly expanding the scope of the issues to be determined beyond Mossop’s pleaded defences. 459 The defence fails in any event. 460 The effect of clauses 24.5 and 24.11 of the subcontract is discussed in these reasons above in the context of the concrete variation claims.320 Clause 24.5 on its terms does not operate as a precondition to entitlement to a variation to the subcontract scope of works. Nor does failure to comply with clause 24.5 bar entitlement. Rather, clause 24.11 provides that the Superintendent must determine a fair and reasonable value for a variation claim and adjust the Subcontract Sum where there is non-compliance with clause 24.5. 461 Mossop’s unpleaded complaints about provision of adequate information should similarly be disregarded.321 Conclusion 462 The steel variation claims are not contractually barred. 319 Written Submissions of the Respondent, section F page 55. 320 See [269]and [271] above. 321 Written Submissions of the Respondent, section I page 64. -- 86 of 106 -- [2024] SADC 1 85 Overall Conclusion 463 For the preceding reasons, the Lifecare subcontract should be rectified to list revision 00 of the relevant structural drawings in Appendix D to reflect the common intention of the parties as to the scope of works allowed in the agreed lump sum price negotiated during the formal tender process and the intended basis of contract as per the accord reached between the parties in the 29 September email exchange. 464 The value of the claims made by Contek based on the value of the OneSteel variations are fair and reasonable, despite the minor discrepancy between them. Accordingly, Contek’s claims for $27,007.66 ex GST for the extra steel variation claims succeed. PART F: LIFECARE PROJECT – TOPIC 7 – BACK CHARGE CLAIMS The Disputes – Back Charge Claims B5, B10, B11 & B13 465 Mossop claims a set off (back charge) for various works carried out by contractors other than Contek at additional cost to Mossop that it alleges were within Contek’s scope of works, including remediation of defective Contek works. These disputes generally concern limited factual disputes of relatively minor values that were the subject of limited oral evidence although vigorously disputed in multiple rounds of written submissions. B5 – Patch & Caulk Balcony Works Back Charge - $10,990.90 ex GST322 466 Mossop’s claim for certain patching and caulking works is summarily pleaded by reference to its back charge claim B5323 for defective concrete works. Mossop’s claim is denied by Contek as not being within its scope of works324 and concerning defects arising from the formwork that was installed by another contractor.325 467 The relevant patching and caulking works are described in an invoice issued by Patch & Caulk Pty Ltd.326 It was not disputed that any of these works were required to be done. 468 Mr Apostolakos’ unchallenged evidence was that some of the invoiced works were unrelated to Contek’s scope of works: that is the caulking works ($600) and materials ($315.90).327 His evidence is consistent with the general description of Contek’s scope of works as set out in Appendix C of the subcontract conditions. 322 $12,089.99 inc GST. 323 Counterclaim [20.5]. 324 Defence to Counterclaim [1]. 325 Defence to Counterclaim [15.4]. 326 Exhibit A7 page 208. 327 T243.18-.21. -- 87 of 106 -- [2024] SADC 1 86 This part of Mossop’s claim was untenable at the outset and was finally conceded by Mossop in its second round of written closing submissions.328 469 The balance of Mossop’s claim ($10,075.00)329 principally concerns a dispute as to whether the patching works were required as a result of Contek’s defective work or that of the previous trade, the formwork contractor who formed the areas where Contek poured concrete. There was no substantive evidence about the removal of concrete splatter works that were included in the charges for the patching works: either as to where the splatter was, how extensive it was, how it got there, or the scope of the remedial works undertaken. This unquantified part of Mossop’s claim should also be rejected as unproven. 470 As to the patching works, it was Mossop’s case that new formwork was used and since Contek’s works were defectively finished, Contek was responsible for the cost of the patching works. Mossop relied on Mr Stringer’s evidence-in-chief that he observed the condition of the relevant formwork, and it was all of good quality.330 In cross-examination, Mr Stringer accepted that second-hand formwork may leave divots or indentations in the finished concrete,331 and although he had oversight of most things, he did not see all the formwork used so he could not be certain it was all new.332 This was an important concession, bearing in mind it is quite probable that Mr Stringer as site manager on a busy construction site did not see all the relevant formwork. 471 Mossop relies on a single photograph allegedly showing new formwork ply.333 It is difficult to discern from the photograph much about the condition of the formwork in one area. The photograph was not shown to any witness. The formwork contractor was not called. 472 Finally, Mossop referred to a contemporaneous email trail as evidencing Mr Apostolakos’ acknowledgement of Contek’s responsibility for the works.334 This evidence is equivocal, it was not put to Mr Apostolakos and is of no real assistance to the Court in resolving this dispute. 473 It was Mr Apostolakos’ evidence that finished areas were blemished and pock-marked because the formwork contractor used recycled and second or third- hand formwork.335 When it was put to him in cross-examination that only new formwork was used, Mr Apostolakos denied it. The only other question he was asked was whether he took any photographs of the second or third-hand formwork, 328 At [132]. 329 I.e. Labour of $9,675 plus materials of $400 plus GST. 330 T589.1-.23. 331 T590.1-.19. 332 T590.20-591.6. 333 Exhibit A4.1 page 146. 334 Exhibit 7 pages 257 to 260. 335 T242.16-.30. -- 88 of 106 -- [2024] SADC 1 87 to which Mr Apostolakos replied he may have.336 There is no basis for disbelieving Mr Apostolakos’ evidence. 474 Whilst Mr Stringer referred in passing to there being other reasons for divots or indentations in the concrete,337 he did not identify those reasons and there was no evidence adduced by Mossop to prove any alternate cause for the divots and indentations in the face of the finished concrete that were patched. That was not surprising because Mossop’s case was simply that the concrete was defectively finished, and it is all Contek’s responsibility because the concrete was its works. 475 On the limited evidence there is, it should be accepted that the cause of the divots and indentations in the face of finished concrete was the use of second-hand formwork. This is a reasonable explanation for the defects in the finished concrete on the evidence and not improbable. 476 The question then remains whether Contek should share any responsibility for the patching works, accepting that the concrete finish was defective and not works that would ordinarily have been required in any event. 477 Mossop submits Contek should have spoken up at the time if the quality of the formwork was not acceptable and would affect its works. As a matter of common sense, there is some force in this submission. For Mr Apostolakos to have observed the formwork was substandard and second or third-hand in the relevant areas he then would have been in a position to assess its unsuitability for Contek to properly carry out its concrete works. Indeed, Mr Stringer confirmed that second-hand formwork would have been noticeable.338 It should also be accepted that Mr Apostolakos as an experienced and competent concreter would have known the areas in question were visible and needed to be properly finished and therefore required new formwork. 478 It follows that Contek should share some responsibility for the defective work resulting from the interface between its works and that of the formwork contractor, as so should Mossop because it was responsible for supervising the formwork subcontractor, a responsibility Mr Stringer openly acknowledged he considered important and was alive to. 479 Bearing in mind the rejection of the unproven and unquantified claim for removal of concrete splatters and taking a broad brush approach, $4,500.00 ex GST (being one half of $9,000.00 ex GST) should be allowed as a back charge and set off against the adjusted subcontract sum for item B5. 336 T471.1-.29. 337 T590.12-.13. 338 T591.25-.31. -- 89 of 106 -- [2024] SADC 1 88 480 Accordingly, Mossop’s back charge claim for item B5 should be allowed in the amount of $4,500.00 ex GST.339 B10 – TC Formwork to Beam Above Ramp – Back Charge - $3,837.00 ex GST340 481 Mossop pleads it required Contek to carry out formwork to the beam above the ramp that it refused to do, and so it engaged others to do these works.341 The works are described in Mossop’s variation order dated 2 August 2018 and refer to formworks to the slab edge carried out on 24 and 25 January 2017.342 These works were for the edge beam of the ground floor slab adjacent to the ramp to the car park to the basement. 482 Contek’s pleaded defence is that these works were not part of its scope of works and were suspended formwork that was required “to be completed by a contractor who has access to, inter alia, materials such as guard rails and edge form.”343 Self-evidently, the relevant formwork was above ground. 483 Mossop submits this formwork was part of Contek’s scope of works but Contek refused to complete these works. Mossop relies on the general description of two items of work in Appendix C to the conditions of subcontract: “Edge formwork” and “Provide all edge forms including forming deep edge rebates at ground floor”.344 484 This dispute principally concerns the contractual meaning of “edge formwork” and “edge forms”. It is uncontroversial that this question is to be determined objectively, not by what either party subjectively thought these terms meant but by how reasonable businesspersons would have understood these terms in the surrounding circumstances known to the parties, together with the purpose and object of the transaction.345 485 It was uncontentious that Mossop had engaged formwork contractors to install formwork on the first and second levels and key elements of the poured concrete structure such as the lift shafts and stairwells. 486 Mr Apostolakos gave evidence that “edge formwork” means in concreting works the edge of a slab “as long as it’s in the dirt”346 and “(a)nything that’s ground level that you can put a pin in and form is our responsibility”.347 He gave evidence that it was industry custom and practice for the concreter to only be 339 $4,950.00 inc GST. 340 $4,220.70 inc GST. 341 Counterclaim [20], [20.7]. 342 Exhibit 7 pages 56 to 57. 343 Reply and Defence to Counterclaim [15.6]. 344 Exhibit A1 page 208. 345 Mount Bruce Mining Pty Ltd v Wright Prospecting Pty Ltd (2015) 256 CLR 104, [46]-[52] as per French CJ, Nettle and Gordon JJ and [107] per Kiefel and Keane JJ. 346 T250.19-.21. 347 T250.30-.31. -- 90 of 106 -- [2024] SADC 1 89 responsible for ground level formwork and that was how the concreter’s responsibilities were separated from those of the formwork contractor.348 His evidence is consistent with what he told Mr Barone (cc to Mr Orlovic and Mr Kemp) in an email sent in March 2017 in the context of formwork required for the first floor.349 487 Mr Apostolakos’ evidence was not challenged in cross-examination or contradicted by any other evidence. His evidence is not inadmissible expert opinion evidence, as Mossop submits. It is evidence about matters within his experience and understanding of industry custom and practice.350 It is cogent evidence of an important and relevant surrounding circumstance bearing on the meaning of “edge formwork” and “edge forms”. 488 Mossop called Mr Orlovic, Mr Stringer and Mr Neil Mossop but did not elicit any evidence on this topic, save to ask Mr Mossop if he was present on site when the beam above the ramp was installed. He was not. 489 Mossop’s objection that industry standard was not pleaded is unpersuasive. The parties’ pleadings concerning the back charges were sparse and loosely worded. Mossop was on notice of the reason for Mr Apostolakos’ objection to its claim from the March 2017 email referred to above that Mossop relied on its submissions for a different point. 490 For completeness, two matters should be mentioned. First, although pleaded, there was no evidence that Contek refused to do the work carried out by TC Formwork. The March 2017 email exchange referred to formwork for the first floor, not the ground floor. Secondly, Mossop referred to the instruction memorandum dated 24 January 2017, issued to TC Formwork by Bill Werner, Mossop’s then site manager, to “supply labour and materials as required by the concreters, to form along the angled precast at the ramp as directed on site”.351 This instruction suggests that the concreters, Contek, would be ‘directing’ where the formworks were required, not that they were responsible for the works. Mr Apostolakos’ unchallenged evidence was that he did not ever ask or instruct TC Formwork to undertake the formwork.352 Mr Werner did not give evidence. 491 On the evidence, it should be accepted that the references in Appendix C - Scope of Works to the conditions of subcontract to “edge formwork” and “edge forms” should be construed according to industry custom and practice as limited to ground floor formwork that can be pinned and braced off the ground as described by Mr Apostolakos in evidence and exclude suspended formwork for edge beams. 348 T250.25-.33. 349 Exhibit A7 page 54. 350 Ritz Hotel Ltd v Charles of the Ritz Ltd (No 7) (1987) 14 NSWLR 104. 351 Exhibit A7 page 46. Emphasis supplied. 352 T252.5-.13. -- 91 of 106 -- [2024] SADC 1 90 492 Accordingly, Mossop’s back charge for “TC formwork to beam above ramp” should be dismissed. B11 – Basement Repairs – Back Charge - $4,359.50 ex GST353 B13 – Partial Rectification of Basement Works – Back Charge - $12,000.00 ex GST354 The Issues 493 Mossop claims a set off (back charge) for two items concerning the basement concrete works carried out by Contek referred to as items B11 and B13. 494 B11 concerns repairs carried out to the basement concrete to grind and patch around lids, inspection points, spoon drains, precast columns, fill and patch holes in concrete and clean concrete slurry of precast walls. These remedial works were carried out by another contractor, High Gloss Solid Plastering, at a cost of $4,359.50 plus GST.355 The reasonableness of the repair costs is not disputed. 495 B13 concerns repairs carried out to sections of the basement concrete floor by Arrunga Surface Solutions (Arrunga) invoiced at a cost of $12,000.00 plus GST.356 The remedial works involved the grinding, hardening and sealing of areas of poorly finished concrete. 496 Mossop’s counterclaim pleads its entitlement to claim a set off by reference to the relevant back charge items that it alleges were for remedial works carried out by other contractors that Contek refused to carry out.357 497 Contek’s defence for both claims alleges that on the day of the pour, there was an approximate average rainfall of 7mm, that against the advice of Contek, Mr Stringer of Mossop directed the pour proceed.358 As regards B11, if Contek’s works are defective, then Mossop is liable for any rectification works as a result of an error in the design and instruction.359 As regards B13, Contek further alleges that Mossop would have borne the cost of the hardener and sealer in any event360 and Mossop cannot claim for betterment.361 498 Contek submits both claims arise out of the same facts, that is the alleged direction to pour during rainfall. Mossop does not suggest otherwise, and it is convenient to address both claims together. 353 $4,795.45 inc GST. 354 $13,200.00 inc GST. 355 Exhibit A7 page 72. 356 Exhibit A7 page 177. 357 Counterclaim [20.8] and [20.10]. 358 Defence to Counterclaim [15.7.2] and [15.7.3]. 359 Defence to Counterclaim [15.7.5]. 360 Defence to Counterclaim [15.9.3]. 361 Defence to Counterclaim [15.9.4]. -- 92 of 106 -- [2024] SADC 1 91 499 Despite Contek’s pleaded denial, at trial there was no real issue that Contek’s concrete works were defective. The photographic evidence shows defective finishes around fittings and spoon drains not draining to sumps (B11) and the defective finished surface of some of the concrete (B13). In cross-examination, Mr Apostolakos “absolutely” agreed the concrete surface was not satisfactorily finished because Contek “couldn’t finish it”.362 As regards B11, he said earlier, when shown photographs of Contek’s works that were not nicely cleaned and finished around the fittings, that it should have been clean and neat and not as it was.363 Inadequate Fall on Spoon Drains 500 As regards B11 and the spoon drains not draining to the sumps, Mr Apostolakos gave evidence to the effect it was not an issue arising from the wet weather but that the falls were miscalculated by Mossop’s site supervisor, Mr Stringer, who gave him a hand-drawn sketch resetting the drainage for the spoon drains.364 Mr Stringer did not recall any of this and did not accept that there were difficulties with the drainage because of any alleged sketch.365 Mr Stringer’s evidence on this topic should be preferred. It is not credible that a competent site supervisor would redesign the level for a drainage system with a hand-drawn sketch and a competent concreter would accept a direction give in such a manner if it was. 501 It should be accepted that Contek is responsible for not adequately grading the fall on the spoon drains. Direction to Pour in Wet Weather 502 It was Contek’s case that its works were not properly finished because there was excessive water inhibiting a proper finish due to Contek pouring during rain at Mossop’s direction. This involved factual disputes about whether it was raining and the ingress of rain into the basement caused the defective surface and whether Mossop directed Contek to proceed to pour in wet conditions against Mr Apostolakos’ advice to defer the pour. 503 Only two witnesses gave evidence on the relevant topics: Mr Apostolakos and Mr Stringer. Their evidence was consistent in material respects: first, that it was raining during the relevant pour;366 secondly, the ingress of water into the basement adversely affected Contek’s ability to properly finish the surface of its concrete works.367 It is not necessary to resolve differences between their evidence concerning the extent of the ingress of water into the basement or establish the 362 T474.31-.34. 363 T259.23-.30. 364 T257.37-258.4. 365 T607.6-.34. 366 T255.21-.22; T579.20-.32. 367 T256.12.19-257.8; T580.1-.9;T581.15-.38. -- 93 of 106 -- [2024] SADC 1 92 amount of rain that fell, although much was made of these differences in an attempt to discredit the other’s witness. 504 Their evidence conflicted on the issue of the alleged direction. Both parties challenged the credit of the other party’s witness, submitting that their evidence should not be accepted about the alleged direction. 505 As regards the alleged direction, in closing Contek submits that the matter of legal principle involved is one of causation368 and the rectification works are Mossop’s responsibility as a direct consequence of Mossop’s demands that the pour continue in unsuitable conditions.369 Its case as pleaded or agitated at trial did not otherwise address why a direction by Mossop to proceed with the pour during rain would absolve Contek contractually from its obligation to properly finish the basement concrete. 506 Mossop submits that the issue is whether the alleged direction constituted a waiver or an estoppel or a concluded and binding agreement to absolve Contek from responsibility for defective work in the circumstances.370 Mossop’s submissions should be accepted as correctly identifying a fundamental legal issue. It is not simply a question of causation as Contek submits. If a verbal direction was given against Mr Apostolakos’ advice as alleged, it would not alone absolve Contek from the responsibility to complete its works properly. Contek’s alleged defence is misconceived and fails regardless. 507 In any event, the evidence overall does not establish that the pour of the basement floor proceeded on Mossop’s insistence against Mr Apostolakos’ advice as plainly as alleged by Mr Apostolakos. The facts established by the evidence are as follows. 508 The documentary evidence shows that by Thursday, 22 June 2017 the basement concrete was half-poured and the second half was due to be poured the following week.371 Contek had set the initial dates. 509 On Friday, 23 June 2017, Mr Stringer sent Mr Apostolakos an email confirming that Mr Kemp had told him that the pours organised for Monday and Tuesday had been moved to Thursday and Friday and they needed to keep them as scheduled because other trades were booked and lift crates and generators were being delivered.372 Later that morning Mr Orlovic sent Mr Stringer, Mr Apostolakos and Mr Kemp an email373 saying he had spoken to Mr Apostolakos and they proposed to meet on Monday to discuss why the pours were delayed. He then said: 368 Written Submissions of the Applicant [199]. 369 Written Submissions of the Applicant [186]-[187]. 370 Written Submissions of the Respondent pages 74 and 75. 371 Exhibit A7 page 129. 372 Exhibit A7 page 140. 373 Exhibit A7 page 141. -- 94 of 106 -- [2024] SADC 1 93 Paul, James, as you know the basement concrete is past being critical and is very important we pour as soon as possible, it was planned for Monday/Tuesday. The lift contractor as well as others (generator install etc.) are waiting and are threatening costs for storage of equipment. Site meeting on Monday at 10am please. 510 Contek’s counsel took Mr Apostolakos to the first email and then led evidence about an issue with the spoon drains affecting the pour dates.374 Whether that was correct or not is beside the point. What is important is that it shows Contek shifted its previously planned pour dates despite Mossop’s resistance to the adverse impact on other trades. Mossop’s objections were reasonable given the late change of plan, yet Contek determined when it would pour despite Mossop’s objections. 511 Further, whilst both Mossop and Contek were under pressure to complete the works, there was no contractual reason for the fourth pour to occur on the day rescheduled by Contek if it was unsuitable due to wet weather. Mr Stringer confirmed that there was flexibility if necessary, but it was his job to maintain pressure to meet program.375 512 It was Mr Apostolakos’ evidence-in-chief that he told Mr Stringer that the pour should not proceed, and Mr Stringer told him: “Absolutely not, we are going ahead with the pour. We’ve got to get this thing open.”376 In cross-examination, Mr Apostolakos’ evidence shifted. He confirmed he said ‘(w)e shouldn’t be pouring, look at the water coming in’ and raised it with someone in charge at Mossop377 but could not say who was in charge that day to whom he spoke.378 He then could not say whether it was Mr Stringer, but admitted he was under constant pressure from Mossop to push the schedule and on the day the instructions were to pour regardless of the water coming in.379 Whilst the conversation occurred a long time ago and he could not recall who it was with, overall his evidence was not persuasive. 513 It was also unsatisfactory that Mr Kemp was not called by Contek given his alleged role in the deferral of the pour and his absence as a witness was unexplained. 514 Mr Stringer first gave evidence that he did not recall insisting when Contek should pour or there being any controversy about the pour going ahead. He explained quite plausibly a number of times that Mossop would have preferred when it was done and would sometimes push around critical tasks if things came 374 T254.2-.37. Given Contek put this email to Mr Apostolakos, its objection about the unfairness of Mossop relying on this email to advance a new case should be rejected. Skeleton Reply Submissions [53]. 375 T611.19-.23. 376 T256.2-.8. 377 T473.23-.38. 378 T473.34-.35. 379 T475.17-.20. -- 95 of 106 -- [2024] SADC 1 94 up,380 but he did not insist on when Contek would pour. Despite being thoroughly cross-examined on the point, he maintained the position that Mossop always like the pours to go as they suggest but “if other things come up [such as] weather etc., we don’t pour. Especially on a finished concrete.”381 It is obvious why that would be the case. 515 Mr Stringer finally conceded that he did not know if he insisted Contek proceed to best meet program on the third and fourth pours, but was emphatic in his denial that he would ever insist anybody pour concrete whilst raining.382 516 Contek’s criticism of Mr Stringer’s evidence about the change in the design of the basement drainage as selective and unreliable generally is overstated. The design change occurred before he started on site. Neither Mr Apostolakos nor Mr Stringer can be criticised strongly about their poor recall of events that occurred many years ago. As the 23 June 2017 email exchange shows, there were ongoing discussions between Mr Apostolakos, Mr Kemp, Mr Orlovic and Mr Stringer about best meeting program, the change made by Contek to the dates of the scheduled pours and the impact on other contractors. However, overall, Mr Stringer’s recollection was better and more reliable than Mr Apostolakos’ account of what happened on this topic. It should be inferred that Mr Apostolakos misconstrued the ongoing discussions about meeting program and whatever Mr Stringer said to him about meeting program for the third and fourth pours as a direction to proceed with the pour in the rain. Betterment 517 The Court will reduce an award of damages for the costs of remediating defective building works to the extent of any betterment. 518 Betterment occurs when rectification works carried out lead to an unearned or excess increase in value when compared to what is contemplated by the contract.383 519 Contrary to Contek’s submissions, it should be accepted that it was necessary to grind the rough finish to sections of the basement concrete and seal it because once ground, the concrete was porous and susceptible to abrasion and dust. There was no evidence indicating that re-trowelling an already hardened surface was a viable alternative to sealing and common sense suggests otherwise. 520 However, introducing a hardener into the sealant was a betterment as was explained by the polished concrete specialist contractor in the covering email to its quotation.384 380 T578.14-.30. 381 T608.2-.8. 382 T611.10-30. 383 Bellgrove v Eldridge (1954) 90 CLR 613. 384 Exhibit A7 page 151. Emphasis supplied. -- 96 of 106 -- [2024] SADC 1 95 Once the concrete has been resurfaced and [sic] the concrete’s surface porosity will be increased and become much easier to deteriorate. It is recommended that surface hardening be undertaken in this case. I have allowed for application of Miraharden Plus which will extend the life of the prepared surface, The Aardcure WBS sealer will then be applied to this to seal and provide further dust proofing. The Miraharden Plus will last within the surface longer that the sealer, so if the sealer does require re-application in the future, the surface will be protected from dusting. This provides a surface that is more abrasion resistant compared to that of an untreated trowel finished floor. 521 Contek’s assertion that the application of a sealer was always contemplated works outside of Contek’s scope of works, and the issues with the defective concrete surface were conveniently used by Mossop as a back charge for a betterment, should be rejected.385 Only the defective sections of the basement were ground, hardened and sealed,386 as Arrunga’s invoice clearly shows.387 522 There is no evidence as to the extra cost involved for just applying the surface hardener. The $12,000.00 ex GST pricing quoted by Arrunga was for grinding 400m2 of textured concrete and the supply and application of one coat of hardener and two coats of sealer. Taking a broad brush approach and bearing in mind Arrunga’s quoted price for the grind works carried out by High Gloss Solid Plastering, the betterment should be quantified at $2,000.00 ex GST, being one third of half of the remediation costs. Conclusion 523 For the reasons set out above, Mossop has succeeded on it counterclaims for the basement concrete remediation works B11 and B13 in the amounts of $4,359.50 ex GST388 and $10,000.00 ex GST389 respectively. PART G: ALDI PROJECT – TOPIC 10 – CAST IN ANGLES Disputed Value - $5,760.00 ex GST390 524 Contek was contracted to supply materials and labour for the concrete slabs and footings for the main building, the in-situ retaining wall footings and walls and the external concrete pavement for the Aldi supermarket in Berri. 525 The parties agree their dispute over this variation claim is confined to the question of what is a fair and reasonable value for Contek’s variation claim. 385 Written Submissions of the Applicant [194]-[196]. 386 T744.24-.30. 387 Exhibit A7 page 176. 388 $4,795.45 inc GST. 389 $11,000.00 inc GST. 390 $6,336.00 inc GST. -- 97 of 106 -- [2024] SADC 1 96 526 Contek submitted a variation claim dated 10 March 2016391 for the additional labour for its works following the redesign of the concrete jointing system in the back-of-house and loading dock areas. Seven cast-in dowelled constructions joints were required in lieu of saw cut joints. The total amount claimed was $14,890.00 ex GST.392 527 Mossop assessed Contek’s variation claim393 by disallowing $5,200.00 ex GST394 claimed for an additional day of pouring for a concrete crew’s labour plus a pump and deducting $3,264.80 ex GST395 for costs of installing the saw cut joints.396 Mossop paid $6,425.20 ex GST397 leaving $8,464.60 ex GST398 in dispute. At trial, Mossop conceded $2,704.80 ex GST399 of its calculation of the costs it deducted for installing the saw joints as excessive, leaving only $560 ex GST400 of that component in dispute. 528 The Court is therefore required to determine the remaining dispute over $5,760.00 ex GST.401 529 It is uncontroversial that the methodology for installing the dowelled construction joints was complicated, time-consuming and involved pouring the concrete slab each side of the joint separately. By comparison, a saw cut joint was made relatively quickly and simply after the concrete slab was poured by chalking the line of the joint and then a worker walking a soft cut machine along the line to cut a 30mm x 3mm joint. 530 Mossop does not dispute Contek’s claim for additional labour to form up and install the cast in angles or Contek’s hourly rates. After hearing Mr Apostolakos’ evidence, Mossop conceded that its deduction for the work involved in making the saw cut joints was excessive, narrowing the dispute to the two components of Mossop’s assessment of Contek’s claim referred to above. 531 The first component concerns Contek’s claim for $5,200.00 ex GST402 for an extra day to pour the concrete slabs. It was Mr Apostolakos’ evidence that the joint redesign required the resequencing of the planned concrete pours into five pours, each requiring a full concreting crew and pump. By reference to the original403 and varied404 pour sequences marked up on slab plans, Mr Apostolakos explained that 391 Exhibit A10 page 43. 392 $16,379.00 inc GST. 393 Exhibit A10 page 53. 394 $5,720.00 inc GST. 395 $3,591.28 inc GST. 396 Exhibit A10 page 53. 397 $7,067.72 inc GST. 398 $9,311.28 inc GST. 399 $2,975.28 inc GST. 400 $616.00 inc GST. 401 $6,336.00 inc GST. 402 $5,7200.00 inc GST. 403 Exhibit A10 page 31. 404 Exhibit A10 page 38. -- 98 of 106 -- [2024] SADC 1 97 the most efficient sequence was to pour the back-of-house and loading dock areas in alternate sections because only one half of the doweled construction joint and corresponding slab could be poured at a time. This changed the size of the pours in those two areas in layman’s terms from one small and one really big pour to two good size pours.405 This required an extra day for a concrete crew and pump as opposed to two men wheelbarrowing in concrete into the smaller areas at opposite ends of the back-of-house area (denoted in yellow on the slab plan). 532 Mossop challenges Contek’s claim as excessive, not making sense and the wheel barrowing not being possible.406 This submission should be rejected for two reasons. First, there is no evidentiary foundation for Mossop’s analysis of the alleged volumes and work required in contradiction to Mr Apostolakos’ evidence. Secondly, while Mr Apostolakos was cross-examined on this variation he was not asked any questions challenging the feasibility of the planned pour sequence. 533 There is therefore no good reason not to accept Mr Apostolakos’ evidence as to why an extra day to pour the concrete slabs was required. Accordingly, Contek’s claim for $5,200.00 ex GST is fair and reasonable. 534 As to the second component of Contek’s claim, a deduction should be made for the labour for the saw cut joints that were not required and omitted from Contek’s scope of works but not to the extent Mossop claims. Accepting that 48m of saw cut joints were no longer required407 and Mr Apostolakos’ evidence as to the nature of the work involved,408 one hour’s work valued at $70.00 ex GST409 would be a fair and reasonable deduction. 535 It follows that Contek claim for the value in dispute succeeds to the extent of $5,690.00 ex GST410 and a fair and reasonable value for Contek’s variation claim is as follows. Ex GST Inc GST Total Claimed $14,890.00 $16,379.00 Less costs of saw joint (I hour @ $70) $70.00 $77.00 Revised Claim $14,820.00 $16,302.00 Less paid by Mossop $6,425.20 $7,067.72 Total Outstanding $8,394.80 $9,234.28 405 T301.1-.11. 406 Balance of Written Submissions of the Respondent [172]. 407 T460.28-.29. 408 T309.8; T459.25-.30. 409 $77.00 inc GST. 410 $6,259.00 inc GST. -- 99 of 106 -- [2024] SADC 1 98 PART H: ALDI PROJECT – TOPIC 11 – ABSENCE FROM SITE Disputed Back Charge - $9,626.36 ex GST411 536 Mossop claims a set off for a back charge for a variation order412 referred to by the parties as B1 for the costs of works it instructed other contractors to carry out for works that were indisputably within Contek’s scope of works. The pleaded basis of the claim is that Contek did not return to site to meet its contractual commitment in line with the construction program.413 Contek denies it refused to return to site.414 537 At trial, it was uncontentious that Contek was not on site when other contractors undertook the works on Mossop’s instruction. 538 Contek submits that no requirement to return to site early had been communicated to it before the Christmas closure. Mossop complains variously that Contek should have been on site to do the relevant works, the relevant works had barely started before the Christmas closure, Mossop and the other contractor were back at work, Mr Apostolakos should have told Mossop he was going away, that he would be uncontactable and when he would be back and had someone in his office to respond to communications in the meantime.415 Further, after he had returned to work in January 2016, Mr Apostolakos was grateful Mossop had a replacement contractor do the pour showing he knew it was a proper back charge.416 539 Mossop’s complaints are a distraction and not relevant contractually. The issue is whether Contek was obliged to be on site and complete its works as scheduled. This depends on the works scheduled in the relevant program and when the Christmas closure occurred. The Christmas Closure 540 The Aldi subcontract provides that Contek must carry out its works within the “Site Hours” unless otherwise scheduled.417 The specified site working hours were Monday to Saturday 7am to 4pm.418 Both the subcontract and second programs showed a Christmas closure that is referred to in the definition of “Business Day” in the subcontract as the dates scheduled by the Master Builders Association of South Australia Inc.419 The dateline in both programs in evidence in hard copy is contracted so that only every alternate day is shown. It is therefore unclear when the Christmas closure was scheduled to start and finish from the programs in evidence. 411 $10,589.00 inc GST. 412 Exhibit A11 page 17. 413 Defence [21.1]. 414 Reply and Defence to Counterclaim [16.1]. 415 Written Submissions of the Respondent Topic 11 [6]-[11]. 416 Ibid [2]-[3]. 417 Exhibit 8 page 13, clause 7 Conditions of Subcontract. 418 Appendix E Exhibit A8 page 46. 419 Exhibit A8 page 9. -- 100 of 106 -- [2024] SADC 1 99 541 However, the dates of the Christmas closure are clearly shown in the “4 Week Program” dated 14 December 2015.420 542 The dateline in the “4 Week Program” is fully expanded so every day is evident showing the Christmas closure is from Wednesday, 23 December 2015 to Sunday, 3 January 2016 inclusive. The start of the Christmas closure is confirmed by task 4, “Close up & pour” finishing on Tuesday, 22 December 2023. 543 In the absence of any contradictory evidence, it is reasonable to infer that the expanded subcontract and second programs scheduled the same Christmas closure as the “4 Week Program”. The Relevant Program 544 The subcontract program dated 11 September 2015 relevantly provided that Contek’s works (task 50) “Excavate, Rod and Pour Strip Footings” would be undertaken between 10 and 18 December 2015.421 This task was the preceding critical task before (task 53) “Precast Concrete Erection”, a task that was not within Contek’s scope of works.422 545 The project was behind schedule by mid-December 2015. The slippage was not of Contek’s making. The second construction program issued by Mossop and dated 21 December 2015 relevantly provided that Contek’s works (task 47) “Excavate, Rod and Pour Strip Footings” was now scheduled to be undertaken between 14 December 2015 and 15 January 2016 and (task 50) “Precast Concrete Erection” was scheduled for 16 to 21 January 2016.423 546 That was the position on 22 December 2015, the last day of works before the Christmas closure according to the then current subcontract program. 547 On the first day of the Christmas closure, Wednesday 23 December 2015, Mossop’s Project Manager, Mr Talbot, issued Contek with the “4 Week Program” by email sent at 1:49pm to Mr Apostolakos stating that “Contek are required back on site on Friday 8th January 2016.” 424 The “4 Week Program” shows as tasks 8 and 9 Contek’s works “Excavate the remaining footings” for 8 January 2016 and “Reo and pour” for Monday 11 to Tuesday 12 January 2016. 548 At 2:00pm that same day, Mr Talbot of Mossop sent Mr Apostolakos of Contek a further email, again attaching the “4 Week Program” and noting that Mossop required propping pads prior to 13 January 2016. 549 He did not receive any reply. 420 Exhibit A11 page 6-7. 421 Exhibit A11 page 2. 422 Ibid. 423 Exhibit A11 page 4. 424 Exhibit 8 page 6-7. -- 101 of 106 -- [2024] SADC 1 100 550 On Monday, 4 January 2016, Mossop’s Subcontract Superintendent, Mr Main, sent Mr Apostolakos and Mr Kemp (cc to Mr Talbot) an email seeking urgent confirmation that Contek would have plant and labour on site to recommence its works on 6 January 2016.425 This was now two days earlier than the “4 Week Program” scheduled date of 8 January 2016 as per the 23 December 2015 emails. 551 On Thursday, 14 January 2016, Mossop’s Project Manager Mr Talbot emailed Mr Apostolakos and informed him that he had been unable to get hold of him in the week beginning 4 January 2016, had organised plant and was about to pour the footings in time for the precast erection.426 552 Mr Apostolakos was the only witness who gave evidence on this topic. His uncontradicted evidence was that he went on holidays before the Christmas closure and was uncontactable until his return on about 14 January 2016. He did not read the 23 December or 4 January emails until his return. He was therefore unaware of the “4 Week Program” and Mossop’s requirement for Contek to return to work earlier than previously scheduled on first 8, then 6 January 2016. Further, if he had known he would have done what was required to meet program. Conclusion 553 In the circumstances found, Contek was entitled to rely on the second program that scheduled completion of the relevant footing works on 15 January 2016. Accordingly, Mossop has not shown any basis under the subcontract for removing the relevant works from Contek’s scope of works and setting off the costs of another contractor undertaking the works. Accordingly, Mossop’s set off claim should be dismissed. PART I: SETTLEMENT DISPUTE Issues in Dispute – Aldi Project Variation Claims B1.0 and B3.1 554 During the course of the trial the parties compromised a number of the claims in dispute. By the end of the trial, the parties were in dispute about the terms of resolution reached as concerns Contek’s variation claims for the cancelled concrete pour (referred to as variation 1.0 or B1.0) and the pylon sign pad footing (referred to as variation 3.1 or B3.1) for the Aldi Project. 555 In essence, Mossop alleges agreement was reached for Contek to forego all its claims for B1.0 ($7,304.00 inc GST) and B3.1 ($6,233.15 inc GST), not just the amounts Contek claimed were in dispute ($2,335.80 inc GST for B1.0 and $958.86 inc GST for B3.1) in successive versions of aide memoires MFI A12 and MFI A19. Contek alleges that the agreement reached did not compromise the amounts it asserted were not disputed by Mossop by reason of admissions in 425 Exhibit A11 page 8. 426 Exhibit A11 pages 9 and 10. -- 102 of 106 -- [2024] SADC 1 101 Mossop’s defence, that is, the difference between its claim and the disputed amount. 556 Mossop relies on an affidavit filed by its solicitor, Mr Anderson, exhibiting the relevant settlement correspondence that passed between the parties’ legal representatives and his version of events.427 Contek relies on an affidavit filed by its solicitor.428 557 The affidavit material discloses that following discussions between counsel on the evening of the second day of trial, an offer of compromise was put in an email sent by Contek’s counsel to Mossop’s counsel and copied to the instructing solicitors. It was proposed that Contek would forego certain claims in each project in exchange for Mossop foregoing its back charges. Relevantly, the offer for the Aldi Project was put in the following terms:429 On Aldi Berri, our client will forego all its claims for items B1, B2, B3.1, B3.2, B3.3 and B3.4 totalling $16,006.35 in exchange for your client foregoing its back charges claims for B1, B2 and B3 totalling $16,657.68. Again, the parties respective claims approximately equal/cancel out one another. 558 The offer for the Aldi Project mirrored a similar offer for the Lifecare Project. The commercial sense of the offer put was clear. Each party would be compromising about the same value so as to limit the issues in the trial given the disproportionate cost of litigating nine claims worth collectively about $33,000.00 that might well cancel one another out. The item numbers and issues were well understood by the parties given the years of dispute. 559 The totals referred to were readily identifiable as the totals of the allegedly disputed GST inclusive amounts for the Aldi Project claims set out in the spreadsheets prepared by Contek and tendered as aide memoires MFI A12 and MFI A19, that had been the subject of much discussion since Contek’s opening on the first day of trial. For three items, B1.0, B2.0 and B3.1, Contek alleged that Mossop had paid or approved certain amounts ($15,763.15 inc GST), so the amount in dispute in each case was not the full amount of Contek’s claim as presented at trial. 560 Indeed, Mossop had approved and paid into Court $4,611.75 of Contek’s claim for B3.1430 and admitted liability in that amount in its defence.431 That was not the case for Contek’s claim B1.0, a claim Mossop fully denied and disputed it had ever paid the amount of $4,968.20 inc GST432 alleged by Contek in its pleading433 and in aide memoires MFI A12 and MFI A19. 427 FDN 99. 428 FDN 100. 429 Exhibit NJA-1 to FDN 99. Emphasis supplied. 430 $4,192.50 ex GST. 431 Defence [11.3.1]. 432 $4,516.55 ex GST. 433 Claim and Defence [16]. -- 103 of 106 -- [2024] SADC 1 102 561 Despite the seemingly obvious, Mossop’s solicitor’s affidavit evidence is to the effect that neither he nor his client Mr Mossop could reconcile to Mossop’s records the total of $16,006.35 for Contek’s claims. However, they were not concerned about an “exact” reconciliation because if the offer was accepted then there would be no further dispute about the items. “Exact” is an odd description, perhaps ‘material’ would be better given the purpose and object of the settlement. 562 No-one on behalf of Mossop sought to clarify the terms of the offer put by Contek’s counsel. Instead, a counteroffer was put by Mossop that was then rejected and countered by a further offer from Contek to the effect that if Mossop wished to press back charge B1 (absence from site) then Contek would maintain its variation claim B2.0 (cast in angles). Again, the commercial sense was objectively obvious since the amounts in dispute for these claims were of approximately the same value. 563 Ultimately, it was agreed that the identified claims other than variation claim B2.0 (cast in angles) and back charge B1 (absence form site) would be settled. Contek’s counsel then reported the agreed resolution of the remaining items to the Court. 564 In resolving this final dispute, the first point to be made is that Mossop’s solicitor’s evidence as to his and his client’s subjective intentions about the terms of settlement are not relevant in determining whether a binding agreement had been reached and its terms. What is relevant is what was reasonably conveyed by what the parties’ representatives said and did, bearing in mind the surrounding circumstances as known to the parties, and the purpose and object of the transaction. 565 The parties’ purpose and object was to reduce the claims to be determined by the Court given the disproportionate cost of continuing to litigate claims of such low value by each foregoing the same approximate value. 566 It should therefore be accepted that Contek’s offer objectively construed was confined to foregoing the allegedly disputed amounts but not the entirety of its claims. Otherwise, Contek would be foregoing disproportionately more than Mossop when the purpose of the proposed settlement was for each to quit its losses to a similar value. It makes even less objective sense for Contek to be proposing to forego amounts approved and/or paid by Mossop for which Mossop had admitted liability, even if whether one of those amounts was paid was in dispute. 567 Objectively construed in the circumstances of this case, the parties’ agreement compromised only the disputed amounts of Contek’s variation claims as set out in aide memoires MFI A12 and MFI A19 save for the excluded variation claim B2.0 (cast in angles) in exchange for a compromise of the Mossop’s back charge claims save for excluded back charge B1 (absence from site). -- 104 of 106 -- [2024] SADC 1 103 568 Therefore Mossop’s contention that the parties’ settlement agreement covers the allegedly agreed amounts for variation claims B1.0 and B3.1 of $4,968.20 and $4,611.75 (both inc GST) respectively should be rejected as should Contek’s contention that it should have judgment for both amounts. 569 Contek should only have judgment in the amount of $4,611.75 inc GST434 for variation claim B3.1 for which Mossop has formally admitted liability in its defence. Contek’s claim for the balance of variation claim B1.0 in the amount of $4,968.20 inc GST435 fails because it was not admitted or paid by Mossop, was not settled and it would be inappropriate to determine a claim that was not properly agitated at trial and proven. PART J: FORM OF JUDGMENT AND JUDGMENT SUM 570 As determined, the Lifecare subcontract should be rectified to list revision 00 of the relevant structural drawings S04, S05 and S23 in Appendix D to reflect the common intention of the parties as to the scope of works allowed in the agreed lump sum price negotiated during the formal tender process and the intended basis of contract. 571 Contek should bring into Court a form of judgment reflecting this determination. 572 For neither the Lifecare nor Aldi subcontracts is the resulting judgment sum simply the product of the value of the discrete variation and back charge claims determined by the Court. There are undisputed unpaid invoiced amounts that need to be taken into account. Some are due to Mossop withholding payment of invoiced amounts due on account of its back charge claims and others are for concessions made during the course of the proceeding as to certain other amounts in dispute. To complicate matters further, amounts were paid into Court by Mossop. 573 As stated above, the parties have not reached final agreement on the impact of their differing positions as to the disputed variation and back charge claims on the adjusted subcontract sums net of payments made by Mossop (either to Contek or into Court) under either the Lifecare or Aldi subcontracts. 574 Whilst there is much common ground, the Court will hear the parties on any remaining dispute as to the net amount due under each of the Lifecare and Aldi subcontracts and interest once the parties have had a proper opportunity to consider the Court’s determination of the disputed (Contek) variation and (Mossop) back charge claims as set out in table below. 434 $4,192.50 ex GST. 435 $4,516.55 ex GST. -- 105 of 106 -- [2024] SADC 1 104 Table 12 No. Description Disputed Value ex GST Determined Value ex GST LifeCare Project V2 Extra Concrete – Ground Floor $31,240.96 $26,028.77 V6 Extra Concrete – First Floor $13,722.65 $6,377.06 V7 Extra Steel – First Floor $13,503.83 $13,503.83 V8 Extra Concrete – Second Floor $13,044.77 $8,249.35 V9 Extra Steel – Second Floor $13,503.83 $13,503.83 B5 Patch & Caulk – Balcony Works -$10,990.90 -$4,500.00 B10 TC Formwork to Beam Above Ramp -$3,837.00 Nil B11 Basement Repairs -$4,359.50 -$4,359.50 B13 Partial Rectification to Basement Works -$12,000.00 -$10,000.00 Total $53,828.64 $48,803.34 Aldi Project B1.0 Cancelled Concrete Pour $4,516.55 Nil B2.0 Extra Cast-in Angles & Slab Redesign $5,760.00 $5,690.00 B3.1 Pylon Sign Pad Footing $4,192.50 $4,192.50 B1 Absence from Site -$9,626.36 Nil Total $4,842.69 $9,882.50 PART K: COSTS 575 The parties should be heard on the question of the costs of the proceeding. -- 106 of 106 --