England and Wales High Court (Technology and Construction Court) Decisions

IN THE HIGH COURT OF JUSTICE
QUEEN'S BENCH DIVISION
TECHNOLOGY AND CONSTRUCTION COURT

		Royal Courts of Justice Strand, London, WC2A 2LL
		27 May 2016

Mrs Justice Carr:

A. Introduction

1. 22 Redington Road, Hampstead, London NW3 7RG ("the property") is a large and prestigious residential property. It is and was at all material times owned beneficially by the Second Claimant, Mrs Katie Cooper ("Mrs Cooper"). From about early 2009 on she lived there with her husband, the First Claimant, Mr Marcus Cooper ("Mr Cooper"), and their three children and staff. In the evening of Thursday, 18^th November 2010, there was a significant flood at the property which caused substantial damage to the property and its contents ("the flood"). Mr and Mrs Cooper were insured with Chubb Insurance Company of Europe SE ("Chubb") in respect of their losses. Chubb in due course settled Mr and Mrs Cooper's claim on their policy for over £10million in the sum of £6.5million.
2. Chubb now brings this subrogated claim to recover all or part of that settlement figure. It alleges that the flood was caused by breach of contract and/or negligence on the part of the Defendant, Thameside Construction Company Limited ("Thameside"), its servants or agents.
3. Thameside is a building contractor. Between 2005 and 2009 Thameside carried out substantial works to the property, converting it into a single residence, refurbishing it and building substantial extensions to the rear and basement, pursuant to a JCT Contract on Intermediate IFC 98 Form (Revision 4) dated 3^rd February 2005 between Mrs Cooper as "Employer" and Thameside as "Contractor" ("the JCT contract"). The allegations made against Thameside relate to the faulty installation of a Polyplumb straight connector ("the Polyplumb connector") onto plastic (polybutylene) piping which ran up to the tap box above the basin in an ensuite bathroom attached to a sixth bedroom on the second (top) floor of the property ("bedroom 6") ("bathroom 6"). The installation included the fitting of the piping into the Polyplumb connector. The piping was to be secured by the use of a grab ring located within the Polyplumb connector. It is said that the grab ring used within the Polyplumb connector was damaged or deformed from previous usage. Alternatively, the (lower) pipe was not inserted fully into the Polyplumb connector, such that the pipe was not secured by the grab ring. In any event, the installation of the pipework and the pipework itself was not reasonably fit for purpose. Nor was the installation carried out in a proper and workmanlike manner with reasonable skill and care. Nor was it installed with materials which were reasonably fit for purpose and of a satisfactory quality. The flood occurred when the pipe separated from the Polyplumb connector as a result of these alleged breaches. The property is not yet re-occupied and remains uninhabited.
4. The claim is that this installation work was carried out by a sub-contractor engaged by Thameside, namely Darenth (Southern) UK Limited and/or Darenth Southern (London) Limited and/or Frank Cosgrove trading as Darenth Southern (together "Darenth"). Thameside is liable to indemnify Mr and Mrs Cooper for losses arising out of Darenth's activities at the property. Alternatively, the possibility is left (even if only faintly) open that it was another sub-contractor of Thameside that carried out this installation work and for which Thameside is responsible.
5. Thameside now accepts that the Polyplumb connector was defective, alternatively that the pipe below it was not inserted properly. It also now accepts that the flood would not have occurred but for these defects. However, it denies liability. Its primary, indeed only defence now, albeit one raised for the first time by way of amendment almost a year after the commencement of proceedings, is that neither it, nor any of its servants or agents, installed the Polyplumb connector that failed. The Polyplumb connector was not installed as part of Thameside's work under the JCT contract and was not installed by anyone acting on behalf of Thameside, its servants or agents, including Darenth.
6. It is this factual dispute, namely the question of whether or not it was Darenth that installed the Polyplumb connector as part of the works under the JCT contract, that lies at the heart of this litigation. It is a "who dunnit": was the Polyplumb connector installed by Thameside, its servants or agents as part of the works under the JCT contract or was it installed by other contractors or sub-contractors outwith the contract and responsibility of Thameside?
7. Thameside has variously advanced other defences, including that the cause of the flood was wholly independent of the works undertaken by Thameside, its servants or agents. It was suggested that the pipework failed because of modifications to the domestic hot water system in about April/May 2009 and October 2010 undertaken on the instruction of Mr and Mrs Cooper and by third parties outside the JCT contract, namely the installation of a heat exchanger and/or the incorporation of a double check valve by Darenth. These were said to have caused pressure surges. It was also suggested that a plastic pipe was not suitable for use in a continuously operated re-circulating system. However, all these contentions have fallen away in the light of the defence experts' final conclusions.
8. On 6^th March 2015 Edwards-Stuart J, on the application of Mr and Mrs Cooper, directed that there should be a split trial on liability and quantum. This is the judgment on liability following a 5 day trial at which the following witnesses of fact gave oral evidence:

a) For Mr and Mrs Cooper: Mr and Mrs Cooper; Peter Beer of Ottima (Specialist Joinery and Furniture) Limited ("Ottima") ("Mr Beer"); Jonathan Evans of Metropolitan Development Consultancy Limited ("MDC") ("Mr Evans"). A written statement from Mr Bachelard of Dr JH Burgoyne and Partners LLP ("Burgoynes"), was agreed;

b) For Thameside: Frank Cosgrove of Darenth ("Mr Cosgrove"); Paul Johnson, a self-employed plumber contracted to Darenth ("Mr Johnson"); Paul McBryde, a carpenter who worked on the property for Thameside ("Mr McBryde"); Glenn Gradwell, contracts manager and a former director of Thameside ("Mr Gradwell"); Michael Lynch, construction site manger for Thameside at the property ("Mr Lynch").

9. Expert evidence was adduced as follows:

a) For Mr and Mrs Cooper: Dr Simon Jones of Burgoynes. Dr Jones is a chartered mechanical engineer specialising in the investigation of incidents of mechanical failures;

b) For Thameside:

i) Mrs Daphne Wasserman of Cadogan International Limited ("Cadogans"). Mrs Wasserman is a chartered engineer;

ii) Mr Gerry Brannigan also of Cadogans. Mr Brannigan is a building services consulting engineer.

10. In the event, none of the experts were required to give oral evidence. Their joint agreed statement dated 25^th February 2016 ultimately sufficed for resolution of the issues as they narrowed.
11. Following this introduction, this judgment is set out in the following parts:

a) Section B: The JCT contract and duties owed by Thameside;

b) Section C: The Polyplumb connector and the cause of the flood;

c) Section D: A general chronological overview of events;

d) Section E: The documentary evidence relating specifically to bathroom 6;

e) Section F: The burden of proof and the fact-finding exercise;

f) Section G: The witnesses;

g) Section H: The access hatch and panel;

h) Section I: Did Mr Johnson (or another Darenth plumber) install the Polyplumb connector?

i) Section J: Possible alternative explanations for the installation of the Polyplumb connector;

j) Section K: Possible adverse inferences;

k) Section L: The position of Ludek;

l) Section M: Conclusion.

B. The JCT contract and duties owed by Thameside

12. The works under the JCT contract were specified by reference to incorporated "Contract Drawings" and "Schedules of Work". They were to be carried out under the direction of "the Architect/the Contract Administrator". MDC was the "Contract Administrator". MDC was also named as the "Quantity Surveyor". The "Contract Sum" in the JCT contract was £2.4million and the Completion Date 25^th June 2006.
13. The JCT contract included the following express terms:

"Intentions of the Parties

Contractor's obligations

1.1 The Contractor shall carry out and complete the Works in a proper and workmanlike manner and in accordance with the Contract Documents identified in the Second recital and with the Health and Safety Plan…

3. Control of the Works

…

Sub-contracting

3.2 The Contractor shall not sub-contract any part of the Works other than in accordance with clause 3.3 without the written consent of the Architect/the Contract Administrator whose consent shall not be unreasonably delayed or withheld. The Contractor shall remain wholly responsible for carrying out and completing the Works in all respects in accordance with clause 1.1 notwithstanding the sub-contracting of any part of the Works.

Named Persons as sub-contractors

…

3.3.1 Where it is stated in the Specification/Schedules of Work/Contract Bills that work described therein for pricing by the Contractor is to be executed by a named person who is to be employed by the Contractor as a sub-contractor the Contractor shall not later than 21 days after entering into this Contract enter into a sub-contract with the named person using Section III of the Form of Tender and Agreement NAM/T referred to in the First recital…

3.3.7 Whether or not a person who has been named as a sub-contractor under any of clauses 3.3.1 to 3.3.5 is responsible to the Employer for exercising reasonable care and skill in:

- the design of the sub-contract works insofar as the sub-contract works have been or will be designed by the named person;

- the selection of the kinds of materials and goods for the sub-contract works insofar as such materials and goods have been or will be selected by the named person; or

- the satisfaction of any performance specification or requirement relating to the sub-contract works,

the Contractor shall not be responsible to the Employer under this Contract for anything to which the above terms relate, nor through the Contractor, shall the person so named or any other sub-contractor be so responsible; provided that this shall not be construed so as to affect the obligations of the Contractor or any sub-contractor in regard to the supply of goods and materials and workmanship.

The provision of this clause 3.3.7 shall apply notwithstanding that the Sub-Contract Sum stated in article 2 of Section III of the Tender and Agreement NAM/T referred to in clause 3.3.1 or 3.3.2 included for the supply of any design, selection or satisfaction as referred to herein, and that such Sub-Contract Sum is included for within the Contract Sum or the Contract Sum as finally adjusted.

…

3.3.9 Save as otherwise expressed in the Conditions the Contractor shall remain wholly responsible for carrying out and completing the Works in all respects in accordance with clause 1.1 notwithstanding the naming of a sub-contractor for the execution of work described in the Specification/Schedules of Work/Contract Bills.

…

Work not forming part of the Contract

3.11 Where the Contract Documents provide for work not forming part of this Contract to be carried out by the Employer or by persons employed or engaged by the Employer, the Contractor shall permit the execution of such work on the site of the Works concurrent with his execution of the Contract Works. Where the Contract Documents do not so provide the Employer may nevertheless with the consent of the Contractor (which consent shall not be unreasonably delayed or withheld) arrange for the execution of such work.

Every person so employed or engaged shall for the purposes of clauses 6.1 [injury and damage] and 6.3 [insurance of the Works] be deemed to be a person for whom the Employer is responsible and not a sub-contractor.

6. Injury, damage and insurance

Injury to persons and property and indemnity to Employer

…

6.1.2 The Contractor shall be liable for, and shall indemnify the Employer against, any expense, liability, loss, claim or proceedings in respect of any loss, injury or damage whatsoever to any property real or personal in so far as such loss, injury or damage arises out of or in the course of or by reason of the carrying out of the Works and to the extent that the same is due to any negligence, breach of statutory duty, omission or default of the Contractor, his servants or agents or of any person employed or engaged upon or in connection with the Works or any part thereof, his servants or agents or of any person who may properly be on the site upon or in connection with the Works or any part thereof, his servants or agents…"

14. It is common ground that the following terms were also implied into the JCT contract:

a) That the materials used in the Works would be reasonably fit for the purpose for which they were required in the works (section 4 (5) of the Supply of Goods and Services Act 1982 ("the Act"));

b) That the materials used would be of satisfactory quality (section 4(2) of the Act); and

c) That the works would be carried out with reasonable care and skill (section 13 of the Act).

15. It is also common ground that Thameside owed a duty of care in tort to both Mr and Mrs Cooper in carrying out the Works to like effect.
16. For the sake of completeness only, I record the additional allegation that Thameside owed a statutory duty to Mrs Cooper, pursuant to section 1 of the Defective Premises Act 1972, to see that the works it undertook were done in a workmanlike and professional manner with proper materials. The existence of any duty under this Act is not admitted by Thameside, but if there was such a duty, Thameside contends that it was limited to an obligation to ensure that the work was undertaken in a workmanlike and professional manner and with proper materials for the purpose of ensuring that the property was fit for occupation when completed. In the event, the allegation adds nothing to the outcome on the merits, and I do not address it further.

C. The Polyplumb connector and the cause of the flood

17. At the time of the flood, in bathroom 6 two vertical plastic pipes ran up from T-connectors to the tap box above the basin. Both pipes had straight connectors on them below the basin, some two-thirds along their length from the T-connectors to the tap box. Facing the basin, the hot water pipe was on the left and the cold on the right. The straight connector on the cold water pipe was a HEP₂0 straight connector. The straight connector on the hot water pipe, as indicated, was a Polyplumb connector, manufactured by Polypipe Building Products Limited.
18. Such connectors are used with flexible plastic piping. They include a capnut, "O" ring and a "grab ring". In use, the pipe is cut to size. Once a pipe insert has been added to the end, the pipe is pushed into the fitting. The O ring creates a water-tight seal and the teeth of the grab ring ensure that the pipe is held fast. Once the pipe is pushed through the grab ring, the teeth dig into the pipe and the pipe cannot be withdrawn. The grab ring can only be removed by loosening the capnut and pushing the grab ring further down the pipe, away from the fitting. The Polyplumb connector's capnuts were dated 2006.
19. Above the connectors was a further small section of pipework which led to the tap box, which contained the workings for the tap. As finally constructed, there were two wall-mounted taps and one spout.
20. It is common ground that the hot water pipe entering the Polyplumb connector (i.e. the lower pipe) separated from the Polyplumb connector with the result that water was pumped out into the property under pressure for a substantial period. This was the cause of the flood.
21. Equally, it is common ground (and, to the extent that it is not, I find) that the most likely, and likely, cause of the separation is the use of a defective grab ring, one which was already deformed when first installed. Upon examination by the experts, four of its sixteen teeth were splayed outwards. Whoever made the joint re-used a deformed Polyplumb fitting. This is not a case of a manufacturing defect or damage from an over-pressure event. Alternatively, though less likely, the cause of the separation was an incompletely inserted pipe. Either way, there was faulty installation. The evidence of Dr Jones in particular is compelling in this regard and, as indicated, there is broad and sufficient agreement between the experts on the issue.
22. The timing of the separation, as the experts agree, is probably explained by the introduction of a check valve in October 2010, a month or so before the flood, as set out below. This created a system which increased the quantity and size of pressure fluctuations being applied to the pipework. The pressure fluctuations probably resulted in the gradual movement of the pipe through the grab ring of the Polyplumb connector.
23. As Thameside accepts, if the Polyplumb connector was installed by it, its servants or agents, Thameside is liable in law both for breach of the express and implied terms of the JCT contract and in negligence.
24. The experts are also agreed that the lower hot water pipe leading to the Polyplumb connector and the upper hot water pipe leading to the tap box were not from the same coils and had their markings running in opposite directions. The printed writing ran in opposite directions and was of a slightly different size and spacing. The Polyplumb connector could not therefore have been inserted simply by cutting a pre-existing continuous run of pipe and then installing a fitting via the narrow access panel below the hand basin. Either the upper or the lower section of pipe would have needed to have been replaced or turned upside down, which could only have been achieved by disconnecting the lower pipe from the T-fitting below or the upper pipe from the tap box above if the upper pipe was already in place.
25. Thus the Polyplumb connector can only have been placed on the hot water pipe before the stud wall with stone/tile facing was erected in front of it, or by demolition of the wall after it had been erected (and subsequent installation of the Polyplumb connector).

D A general chronological overview of events

26. The following overview is based essentially on the facts and matters that are non-controversial and/or based on the documents. Areas of contention will be highlighted as necessary.
27. The leasehold of the property had been acquired in about 2001 when it consisted of four flats held on a lease. Upon the freehold of the property being obtained, Mrs Cooper became its beneficial owner in 2003. The Coopers' intention was to convert it into a single residential family home.
28. Some initial enabling works were carried out but ceased in about July 2004. On 22^nd January 2005 Mrs Cooper and Thameside agreed a "Priced Contract Schedule of works" for the second phase of works. Then, as already indicated, Mrs Cooper entered into the JCT contract on 3^rd February 2005. Sheldon Andrews (later The Sheldon Studio Limited) (together "Sheldon") was appointed separately as interior designer.
29. It is common ground that:

a) the installation of the pipework necessary to deliver hot and cold water to the taps for the basin in bathroom 6 was included under the JCT contract;

b) Thameside sub-contracted its mechanical and electrical and plumbing obligations under the JCT contract to Darenth;

c) Darenth was not a "nominated" sub-contractor.

30. The scope of the works changed significantly during the life of the JCT contract. Thus, as at January 2009, valuation no. 53 certified £5.364 million for payment (albeit that this appears to have included monies for payment for the enabling works). The last valuation (no. 59) was dated 2^nd December 2009. In terms of the mechanical and electrical installation, the initial estimate was £219,000. At the time of practical completion the cost was in excess of £1 million.
31. The scope of the works under the JCT contract was also reduced, including as follows:

a) Specialist joinery and furniture works were made the subject of a separate direct contract between Mr and Mrs Cooper and Ottima. Mr Beer was Ottima's owner and managing director. Ottima supplied the vanity unit above the basin in bathroom 6;

b) Specialist stoneworks were taken out of the JCT contract and made the subject of a separate contract between Signature Stone Limited ("Signature") and the Coopers either direct or via Ottima. Mr Jose Nona Balola ("Mr Balola") was a director of Signature from June 2005 to December 2011. It appears that Signature entered into creditors' voluntary liquidation in June 2012 and was dissolved in December 2013. Signature supplied the basin, and the stone for the wall below and around the basin in bathroom 6.

32. Mr Beer's evidence, which I accept in this regard, is that Ottima was asked to manage Signature, because there were reliability issues with Signature. There was a significant overlap between the work of Signature and that of Ottima. So Ottima would give Signature setting out drawings, for example. And Ottima also paid Signature, with money coming from Mr Cooper through Ottima to Signature. Often therefore, entries in the site meeting minutes to Ottima were references to Ottima being required to chase Signature to action an item or items.
33. Ottima also had a connection with a Mr Ludek Tucny ("Mr Tucny") of Ludek Build Limited and/or All about the House Limited (together "Ludek"). Mr Beer's evidence was that Ottima used Ludek as its installer on site. Thus from 2006 onwards Ludek also had a presence on site at the property. There is no suggestion that Ludek was contracted to or acting for Thameside in any way when acting in this arrangement with Ottima.
34. Ludek was then also introduced independently to the project as the finishing contractor in July 2008. It appears that Ludek's quotation for finishing works was accepted by the Coopers in late July 2008 and terms of engagement agreed. There is a dispute as to whether, when acting as finishing contractor, Ludek was acting as Thameside's servant or agent, as set out and addressed in more detail in section L below. There is no suggestion that Ludek was ever engaged by Thameside to carry out plumbing works at the property. Ludek's quotation in July 2008 expressly excluded plumbing works. However, it appears that Ludek had the capacity to provide plumbing services. Thus in April 2011 Ludek was providing plumbing services (post-flood) at the property and also at the rental address where the Cooper family was then living.
35. It appears that there was no formal contract between Thameside and Darenth. Darenth was simply paid on the basis of monthly valuations.
36. There does not appear to have been a certificate of practical completion. MDC wrote to Mr Cooper in December 2010 stating that:

"Practical completion, as such, took place in January 2009. There is no certificate."

37. In his evidence, Mr Evans stated that practical completion took place on 31^st May 2009.
38. Mr and Mrs Cooper moved into the property in about early 2009. Works carried on after the Cooper family moved in. In late April 2009 a heat exchanger was installed in the plant room to address a problem with inadequate shower pressure. It was designed by Mr Gary Banger of Price Gardner Services Consultants Limited. It reconfigured the domestic hot water system so as to allow for an increase in the nominal working pressure from approximately 3.5 to 5 bar at basement level. The result of this was to increase the pressure in the main shower room and throughout the house. In respect of bathroom 6, the experts are agreed that this would have increased the pressure from approximately 2.5 to 4 bar.
39. A 32-page list of outstanding or additional or snagging items was prepared dated 22^nd June 2009. General item 7 related to water pressure: Darenth was to confirm that the water pressure had been increased to all outlets, together with a report indicating the current pressure at each outlet. On 2^nd November 2009 Darenth produced a document recording pressure test results, including for bathroom 6.
40. The redesign of the system in April 2009 to incorporate the heat exchanger had the effect of allowing hot water in the hot water pipes to escape into the cold water side of the system. To remedy this, in October 2010, a non-return (check) valve was inserted, creating a closed circuit hot water system when no water was being drawn off. This was installed by Darenth outside the scope of its works under the JCT contract.
41. As already indicated, Thameside originally contended that it was the installation of the heat exchanger and check valve that had caused the flood, because it would have led to significant pressure fluctuations in a closed system. However, Thameside's experts now agree that, given the presence of a pressure relief valve on the heat exchanger set at 7 bar, any pressure increase would have been limited to approximately 2 bar (from 5 bar to the maximum 7 bar). The effect of this is that the pressure within the system would have fluctuated between 4 and 7 bar. A properly made joint would not have failed in the event of such relatively small fluctuations in pressure. The redesign cannot therefore be said to be the cause of the flood. However, it may (and in my judgment does) explain the timing for the flood, in the sense that even small temperature related pressure increases could lead to the joint separating.
42. The flood itself occurred in the early hours of the evening when Mr and Mrs Cooper were in the master bedroom and bathroom. Water suddenly started pouring through the ceiling. Mr Cooper's recollection is that he immediately called Darenth, then Thameside and then his emergency plumber, Mr Mark Hebden. Mr Hebden was the only person he was able to speak to. Mr Cooper tried to find the cause of the leak and tried himself to stem the water with his hands. He tried to find the mains water tap. He put buckets around and took his family to safety, fearing an electrical accident.
43. There are competing recollections as to the order of people who then arrived at the property and who did what. The differences are not ultimately material, save perhaps in relation to credibility issues. Mr Cooper's recollection, in the context of what was a very traumatic event for him, is that Mr Hebden was first on site. Mr Cooper took him up to bathroom 6. Mr Hebden put the pipe back in its fitting and turned the mains water off. Others arrived later. Mr McBryde recorded events in an email of 21^st November 2010: he was called by Thameside at around 7pm and asked to attend a problem in one of the top floor bathrooms. He arrived at about 7.20pm, was met by Mr Cooper, and headed straight to the top floor. He found the failed joint, pushed the pipe back in, went downstairs and turned the water off at the pump set. He called a plumbing contractor and a cleaning company, both of which arrived at around 8pm. Mr Cooper had also called a plumber. The two plumbers who arrived made sure that a new joint was installed and turned the water back on. In his evidence, Mr McBryde confirmed that the plumber whom he called and who subsequently arrived was Mr Johnson. Mr Cooper did not remember meeting Mr McBryde. Mr Hebden was not called to give evidence. But on 7^th December 2010 he wrote a document stating that he was called at around 8.15pm on the evening of the flood, arriving at around 9pm. He found a burst pipe in bedroom 6. He temporarily rejoined the pipe and turned the hot water supply off in the basement plant room. There was no obvious damage to the fittings or pipe but as a precaution he replaced the joint. Mr Johnson's evidence is consistent with that of Mr McBryde. Mr Johnson states that he arrived at the property at around 8 to 8.30pm, at about the same time as another plumber, Mr Hebden. Mr McBryde told Mr Johnson that he had switched the water off. Mr Johnson went up to bathroom 6 with Mr Hebden (and an apprentice of Mr Hebden). When he got there, there was no water gushing out and the pipe beneath the basin was in its fitting. He turned the water back on and returned to bathroom 6 where there was no leaking. Mr Cooper wanted the fitting changed, so after switching off the water again, Mr Johnson installed a new HEP₂0 fitting in the presence of Mr Hebden who was observing. Either he or Mr Hebden provided the new fitting.
44. On 19^th November 2010 Thameside emailed Mr Cosgrove stating that Mr Johnson had repaired the failed joint and taken it away. It needed to be returned immediately. Mr Cosgrove responded on the same day to say that Mr Johnson had left the body of the fitting on site. Mr Johnson had not been able to get the clip rings off the pipe so he pushed the rings and their respective threaded nuts further up the pipe so that he could get another fitting in place. The new fitting had been supplied by Mr Cooper's plumber.
45. In so far as it matters, on the state of the evidence before me, I prefer the recollection of Mr McBryde to that of Mr Cooper and Mr Hebden, as supported by the evidence of Mr Johnson. Mr McBryde recorded the sequence of events near contemporaneously, on 21^st November 2010. Mr Cooper was understandably in a state of shock and distress at the time of the flood. Mr McBryde, not Mr Hebden, was first on site, as confirmed amongst other things by Mr Hebden's own recollection of timings and by the recollection of Mr Johnson. Mr McBryde pushed the pipe back in and turned the water off from the basement plant room. Mr Johnson and Mr Hebden then arrived. One or other of Mr Johnson and Mr Hebden then installed a new fitting. I find that it was probably Mr Johnson who did so, as he says he did, given the other inaccuracies in Mr Hebden's document of 7^th December 2010, the consistency of evidence between Mr Johnson and Mr McBryde and Mr Cosgrove's response on 19^th November 2010 (which can safely be assumed to have been based on what Mr Johnson told him at the time).
46. Neither Mr Cosgrove nor Mr Johnson informed Thameside (or anyone else) at the time or immediately after the flood that Darenth had not installed the failed joint. It is suggested that this is "nothing short of astounding", if it was true that Darenth had not installed the failed joint. I return to this below.
47. Mr Johnson accepted that on the evening of the flood it was clear that there was a major crisis not just for the Coopers but potentially for him or Darenth. His evidence however was that on the night of the flood the fact that he had not installed the failed joint was not his focus – it would have been "the very last thing on [his] mind". He stated that he did inform Mr Cosgrove that he had not installed the two connectors on Mr Cosgrove's return from holiday – they were rogue fittings. He said that matters then went "oddly quiet". Nothing much was really discussed. He never said anything directly to Thameside, although he was working on another project for Darenth with Thameside; he had been working for Darenth, not Thameside at the property.
48. Mr Cosgrove also confirmed that he understood when he returned from holiday that this was a major incident in a most expensive property. He confirmed that Mr Johnson had told him at some point that he had not installed the straight connectors. He confirmed that he never told Thameside this directly, even though Darenth was working for Thameside on another project. Burgoynes were on site investigating. He assumed that all matters had been discussed and that Thameside was fully aware of the true position. He simply informed his insurance brokers of the incident and was told not to make any statements about the incident and to forward all future correspondence to them. He could not understand how Thameside came to make the admissions that it did.
49. As to those admissions, Thameside's insurers were notified on 2^nd December 2010 of a potential claim. By 21^st December 2010 Thameside's insurers had instructed loss adjusters, Cunningham Lindsey Constructions ("Cunninghams"). As at March 2011 Cunninghams' position was that the works effected by Darenth were likely to have included installation of the failed joint. In July 2011 Cunninghams admitted that the design and installation of the failed joint was undertaken by a mechanical sub-contractor to Thameside, and "to the best of their knowledge and belief" by Darenth.
50. Proceedings having been commenced in April 2014, Thameside served a defence in September 2014. It expressly admitted that the Polyplumb connector had been installed in bathroom 6 by Darenth. However, on 6^th March 2015 Thameside successfully sought permission to amend its defence so as to withdraw that admission and to deny that Darenth had carried out the relevant work.
51. Mr Johnson's unchallenged evidence was that he was never approached by anyone from Thameside directly for an account of events. Nor was he ever approached by any loss adjuster. The first time he was approached and interviewed (and then by Thameside's solicitors) was November and December 2014. The first time that Mr Cosgrove was so interviewed was in December 2014.

E. The documentary evidence relating specifically to bathroom 6

52. It is necessary to set out, by reference to the available material documentation, some of the detail relating to works and progress in bathroom 6 so far as the basin, pipework and vanity unit are concerned. Where there are contentious material issues of fact, I address the documentary evidence alongside the evidence of the relevant witnesses later in sections I and J.
53. There were three bathrooms on the second floor of the property, an ensuite bathroom to bedroom 4 ("bathroom 4") and an ensuite bathroom to bedroom 5 ("bathroom 5") and bathroom 6. Bathrooms 5 and 6 appear to have progressed broadly in parallel; they were mirror images of each other. Bathroom 4 was very different to bathrooms 5 and 6. Bedroom 4 was on the other side of the wall behind the basin in bathroom 6 and larger than bathrooms 5 and 6.
54. No drawings for bathroom 6 (or 5) ever showed an access panel below the basin. Early sectional elevation drawings for bathroom 6 (and 5) (dated July 2005) show wall mounted taps.
55. On 11^th April 2006 MDC produced an "Ottima priced contract specification" showing works for bathroom 6 as including limestone floor slabs, limestone wall slabs to walls and window reveals, limestone worktop and basin with upstand to vanity unit, flush limestone shower tray, vanity unit carcass and casing compromising limestone covered marine ply casing and upstand, and a mirrored unit over vanity basin.
56. On 30^th August 2006 Mr Cosgrove wrote to Thameside enclosing a priced sanitary specification with added anticipated costs for installation. For bathroom 6 (and bathroom 5) the specification referred to a "wall mounted basin mixer".
57. On 1^st November 2006 Sheldon minutes record Mr Beer confirming that the vanity unit in bathroom 4 had been fitted and Ottima was ready to "do Bath 5 and 6". The unit in bathroom 6 at that stage was based on a 2006 Ottima drawing showing a unit 990mm wide and 800mm high with a hole for access. The height from the ground to the top of the basin was 850mm.
58. On 13^th November 2006 Mr Cosgrove wrote to Thameside as follows:

"...As there has been little progress on site over the past few months I am therefore detailing services information that is still outstanding and which must be confirmed before any real progress can be achieved:

1. O[t]tima are now fitting finished furniture in Bathrooms but to-date there is no sanitary/brassware schedule. Although all of our services are in position in partitions, final fix of the ply cladding cannot occur until the carcassing of the brassware is complete. In most cases this means the rear of the diverters/taps must be in position and wastes positioned exactly to accept the sanitary ware…."

59. On 8^th December 2006 Thameside wrote to MDC, following receipt of the revised sanitary schedule from Sheldon, enclosing a detailed costed supply and installation summary of items, as prepared by Darenth. In relation to bathroom 6 (and bathroom 5), reference was made for the first time to a "deck mounted monoblock mixer tap". This appears to have emanated from Sheldon's schedule, which referred to "deck mounted" as opposed to "wall mounted" tap for the first time. On the same day Mr Cosgrove wrote to Thameside enclosing a schedule based on the same revised sanitary specification.
60. On the same day Mrs Cooper emailed MDC saying, in relation to sanitary ware, that she had spoken to Mr Cosgrove who was ready to approve the order which she wanted to place as soon as possible.
61. On 15^th December 2006 Thameside wrote to MDC stating that it understood that Darenth had requested elevational drawings of each of the bathrooms to enable the correct positioning of the various appliances, and particularly the control brassware that would be hidden behind various panelling. Installation works would be unable to commence before this information was issued.
62. Mr Johnson's diary for 2006 suggests that Mr Johnson worked at the property at least on the following dates in 2006: 27^th and 28^th February, 28^th April, 2^nd May, 19^th to 22^nd June, 25^th September, 23^rd and 24^th November, 29^th and 30^th November, 1st, 4^th, 5^th, 8^th, 14^th, 15^th, and 19^th to 21^st December. The diary entry for 21^st June 2006 reads: "…Re-run services in studwork top floor bathroom". The entry for 25^th September refers to service pipes to the boiler room after the lift shaft was formed. The entries from 23^rd November 2006 onwards to the end of the year refer to the boiler house/room.
63. It would appear that by 10^th January 2007 the first vanity unit and basin had been both installed and removed from bathroom 6 (and bathroom 5). Mr Beer stated that the basin was removed, as well as the vanity unit. On 10^th January 2007 Mr Beer emailed Thameside as follows with a progress report:

"Bathrooms 5 & 6, Vanity's [sic] made fitted, removed and brought back to workshop. Now being redesigned. Waiting for sanitary ware and plumbing before stone can be fitted. Vanity being repriced along with solid stone basin. Existing ones to be save[d] to see what can be reused..."

64. On 17^th January 2007 Mr Beer emailed MDC asking Mr Shutler to look at an attachment which included the following entry :

"Bathroom 6 mark 2 Smaller unit to be drawn and costed. The unit will also need steel support arms for the sink to be made."

65. An identical entry was made for bathroom 5.
66. On 18^th January 2007 Ottima produced revision A to its drawings for bathroom 6 (and bathroom 5). The width of the vanity unit was reduced to 800 mm, and the depth of the sink also reduced. A niche above the tap box was removed.
67. On 1^st February 2007 Mr Cosgrove wrote to MDC as follows:

"Further to our telephone conversation yesterday I have now fully investigated the sanitary ware schedule ordered from Wash with the Bathroom drawings issued on 26^th January 2007 for the three second floor shower rooms …

En suite Bathroom 6

…Basin

Gessi Retangolo deck mounted monoblock mixer tap chrome 20001

The Ottima drawing details a chrome wall mounted tap discharging into the bespoke basin. Should the tap be chrome 20085? There is no waste specified and we assume this will be supplied with the bespoke basin…."

(Chrome 20085 taps were wall mounted. Chrome 20001 were deck mounted). The same comment was made for bathroom 5.

68. There is no suggestion that a deck mounted tap was ever installed in bathroom 6 (or 5), consistent with the goods being returned (unused) to the supplier, as Mr Evans confirmed in evidence. On 2^nd February 2007 Mr Cosgrove wrote to the sanitary ware supplier stating that he would make contact separately in relation to the replacement (wall mounted instead of deck mounted) taps. He enclosed that letter with a letter of the same date to MDC chasing for confirmation of the position on the taps as soon as possible. On 13^th February 2007 Mr Cosgrove wrote to arrange for collection of the deck mounted and delivery of the wall mounted taps.
69. On 12^th March 2007 revisions B and C of Ottima's drawings for bathroom 6 (and bathroom 5) were produced, reducing the height of the sink to 100mm and increasing its depth by 30mm.
70. Thameside's case is that by the end of March 2007, the first fix plumbing works were complete. Mr Johnson went on holiday for some 6 weeks or so on 2^nd April 2007, his entry abroad being recorded in his passport.
71. On 4^th April 2007 Mr Gradwell (of Thameside) wrote to MDC as follows:

"1. Set out and size of wall slot required to shower rooms 5 & 6 to receive cabinet and basins. Thameside… to remove ply fitted by Ottima and prepare opening accordingly…"

72. On 9^th April 2007 Thameside produced a revised list of tasks including:

"Showerrooms 5 & 6 units & stone 10 days start Tuesday 010507 finish mon 140507"

73. Revision D of Ottima's drawings for bathroom 6 (and bathroom 5) dated 12^th April 2007 increased the size of the sink on each side of the bowl, so as to provide wider shelves on the sides of the sink.
74. On 18^th April 2007 Thameside recorded the tiler being on site and asked who was co-ordinating the works. On the same day MDC emailed Thameside as follows:

"Ottima have programmed to be onsite on Tuesday 24^th April at which time they will be getting on with all ensuite bathrooms…

Ottima are supposed to be co-ordinating with Signature... and Darren [of Sheldon]."

75. On 23^rd April 2007 Darenth wrote to Thameside recording that the majority of the sanitary ware had now been "piped up, located and in the case of brassware the final fix removed and stored". In relation to bathrooms 5 and 6, the towel rails could not be located as positioned and had been relocated between the Ottima cabinet and the shower. This involved the re-routing of radiator feeds to new positions.
76. Ottima was due to be on site on 24^th April 2007. On 24^th April 2007 Ottima applied for payment for stonework on bathrooms 4, 5 and 6 in the sum of £11,500.
77. Minutes of a site meeting on 1^st May 2007 record Ottima as being due to start bathrooms 5 and 6 that week. On one version of the minutes, a manuscript entry appears alongside: "Outstanding. JE [Mr Evans] to chase".
78. On 8^th May 2007 site meeting minutes still record:

"1.52 Ottima and Signature Stone to start bathroom 5 and 6 this week. Outstanding."

79. On one version of the minutes, the word "outstanding" is crossed out, suggesting that Ottima and Signature had started their works around this time. Mr Beer confirmed that it was around this time that the basin and vanity unit went in again.
80. On 15^th June 2007 Darenth wrote to Thameside in relation to bathroom 6 recording that the following works had been carried out:

"… Extend cables to heated mirror pad now that Ottima basin is installed."

81. As indicated above, this basin was supported on steel brackets, according to Mr Beer, installed by Ludek. The two L-shaped brackets can be seen immediately below the basin in various photographs and drawings. They were fixed to the stud wall and held together with bolts.
82. On 19^th June 2007 Thameside emailed confirmation of "verbal" site instructions for second fix plumbing as follows:

"… To second fix bedrooms and ensuites 4, 5 & 6 electrically, with white plates to the power. Light fittings as approved. Protect the stone in 5 & 6, have the sloped soffits plastered and fit the sanitaryware, taps and shower fittings."

83. This instruction indicates that the stonework was in place by this date at the latest.
84. There is a photograph of the basin and surrounding area in bathroom 6 dated 3^rd July 2007. It confirms that the first fix plumbing works and wall lining have been completed. The photograph shows the basin and vanity unit fitted and the stonework, a limestone slab/tiling, on the enclosing wall completed. There is a piece of timber in place und erneath the basin, presumably as support. Mr Beer assumed that it was support for the basin whilst adhesive was applied.
85. It is common ground that the wall with its tiling in place prevented any access to the pipework underneath the basin, subject to the existence of an access hatch being in situ, as to which there is a dispute. For Mr and Mrs Cooper it is said that there was such a hatch; Thameside denies this. The photograph does not show a hatch. But because of the angle from which the photograph was taken, it is possible that it would not appear, even if it was there. I address this dispute in more detail in section H below.
86. On 9^th July 2007 Darenth wrote to the sanitary and brassware supplier requesting two short throw spouts for the Gessi Rettangolo wall mounted tap, spout length 120mm from back plate to end of spout. The schedule enclosed referred to a deck mounted and a wall mounted monoblock mixer tap for bathroom 6 (and bathroom 5).
87. On the same day, 9^th July 2007, Signature is recorded (in a letter from Thameside dated 9^th August 2007) as being on site.
88. On 15^th July 2007 site meeting minutes record:

"Bedroom 6 Ensuite

… 1.35 Supply and fix stone below basin. Ottima"

(with an identical entry for bathroom 5).

89. On 23rd August 2007 MDC sent out a general email requesting that the project be "speeded up". It was presently "giving the appearance of a snail". Lists of works to be completed prepared by MDC on 5th and 18th September 2007 recorded the supply and fixing of a stone access panel below the basin in bathroom 6 (and bathroom 5) as being due for completion by Ottima by 5th October 2007.
90. On 19^th September 2007 Mr Gradwell (of Thameside) emailed MDC to complain about non-attendance by Ottima or Signature – with no more than 5 days' attendance over the previous 10 weeks.
91. On 28^th November 2007 site meeting minutes record that the supply and fixing of the stone access panel in bathrooms 5 and 6 was still outstanding. Additionally, the stone around the waste in the sink was to be polished to get rid of the "excessive gap". The waste pipe was then to be installed in a central position in relation to the hole.
92. Site meeting minutes for 18^th January 2008 recorded as follows:

"Bedroom 6 ensuite

1.01 Supply stone access panel and fix on ply access board fixed on magnets and pull catches below basin and mastic in place. Outstanding Signature Stone/Ottima"

with an identical entry for bathroom 5.

93. On 2nd April 2008 MDC emailed Thameside as follows:

"Can you please organise for the following bits to be completed as soon as possible on the second and first floor so that Ottima and Jose can get the top floor finished and continue with the first:

The ply access panels under the basins in en suites to bedrooms 5 and 6 need fixing properly so Jose can fix the stone to it…"

94. On 17^th April 2008 Mr Cosgrove emailed MDC about the waste pipes in bathrooms 4, 5 and 6.

"…This has been going on from before Christmas… The holes Signature… have drilled are not only too large but slightly egg shaped. Signature… have tried to recess the outer rim of the waste to be flush with the stone which has not been sufficiently accurate as they have tried to carry out the work on site instead of drilling the stone on a jig."

95. Site meeting minutes for 10^th June 2008 recorded for both bathrooms 5 and 6:

"... Supply stone access panel and fix with a mastic joint – Signature Stone/Ottima"

96. Two progress meetings appear to have taken place on 1^st July 2008, and one site meeting. Minutes of one progress meeting record:

"2^nd Floor Bathrooms – all stonework completed except for architraves Awaiting basin waste detail. JB [Signature] agreed to remake the basins. Shower screen and mirror trim details required. Vanity units to be returned to site by 14^th July 2008."

97. This would suggest that the basin and vanity units had been removed again (a second time) and were to be reinstalled (a third time). It may be that the vanity unit in bathroom 6 was not removed, only the vanity unit in bathroom 4: Mr Beer thought that to be the case and Mr Gradwelll was not sure. But on any view the basin was removed twice and installed three times and the vanity unit removed once and installed twice.
98. Minutes of the other progress meeting on that day record:

"Access for Maintenance. [Mr Beer] and [Mr Balola] requested details of the bath access panels and [MDC/Sheldon Studios] to sort out. [Mrs Cooper] advised that all areas had to be readily accessible and she did not want to be breaking out stone etc so that ordinary maintenance could be carried out. [MDC/Sheldon Studios] to take this on board and this will require alterations to areas elsewhere where the practical side of things has been totally forsaken for design. URGENT – 7 DAYS"

99. Minutes of the site meeting on 1^st July 2008 record:

"… 1.38 JB [Signature] to either source new waste for approval by DG that fits the holes already in the basins or he is to change the basin bases and recut the holes to suit the waste on site."

100. The supply of stone access panel and fixing with a mastic joint was recorded as outstanding for both bathrooms 5 and 6.
101. What appears to be an Ottima record dated June 2008 records the stone access panel in bathroom 6 as being finished "by 4^th July 2008".
102. Minutes of progress meetings on 15^th and 22^nd July 2008 record:

"2^nd Floor Bathrooms – all stonework completed except for architraves. Awaiting basin waste detail. JB [Signature] agreed to remake the basins and will be delivered this week. Shower screen and mirror trim details required. Vanity units not yet returned to site. Will mostly be dealt with within LT [Ludek] contract period. Shower trays to be broken out and replaced with Dallmer styled outlets with removable tops so that proper access can be afforded…"

103. Minutes of a progress meeting on 28^th July 2008 repeat this entry with the additional words: "Nothing has happened in the past week".
104. Minutes of a progress meeting on 23^rd September 2008 record:

"32. The ensuites to bedrooms 4, 5 and 6 can now be completed and should be as soon as possible. Mastic contractor to be appointed by Darren – Ludek to advise when the rooms will be ready for him. OUTSTANDING Ludek/Signature.../Ottima/DG [Sheldon]"

105. On 30^th September and 7^th October 2008 programme meeting minutes recorded that Signature was to complete all bathrooms on the 1^st and 2^nd floors. The action item was urgent for Ludek, Signature and Ottima.
106. MDC's snagging list dated 22^nd June 2009 recorded as an outstanding item for Signature/Ludek the adjusting and making good the panel under the basin in bathroom 6. The same entry was made for bathroom 5, with the additional word "clean".

F. The burden of proof and the fact-finding exercise

107. The burden of proof lies throughout on Mr and Mrs Cooper to prove, on a balance of probabilities, that the failed Polyplumb connector was installed by Thameside or one of Thameside's sub-contractors carrying out works under the JCT contract. For the claim to succeed it does not have to be proved why or when the Polyplumb connector was so installed, though of course issues of rationale and timing may be relevant to the question of who it was that carried out the installation. Equally, Thameside does not have to prove that some other party installed the Polyplumb connector. But if there is no possible alternative other than that Mr Johnson or someone else at Darenth or otherwise engaged by Thameside could have installed the Polyplumb connector, then that will clearly be relevant to the question of liability.
108. The position was well settled in Rhesa Shipping Co v Edmunds ("The Popi M") [1985] AC 948. There the sole question for the appellate court was whether, on the basis of the first instance judge's primary findings of fact, the judge (and the Court of Appeal) was justified in drawing the inference that the ship was, on a balance of probabilities, lost by perils of the sea. Lord Brandon stated (at 951B-C):

"In approaching this question it is important that two matters should be borne constantly in mind. The first matter is that the burden of proving, on a balance of probabilities, that the ship was lost by perils of the sea, is and remains throughout on the shipowners. Although it is open to underwriters to suggest and seek to prove some other cause of loss, against which the ship was not insured, there is no obligation on them to do so. Moreover, if they chose to do so, there is no obligation on them to prove, even on a balance of probabilities, the truth of their alternative case."

109. Lord Brandon went on to make it clear that it is always open to a trial judge to find, on an examination of all the evidence and probabilities, that there was doubt about what had been the real cause of the loss. In these circumstances, the claimant will have failed to prove his case (at 951D-E):

"The second matter is that it is always open to a court, even after the kind of prolonged inquiry with a mass of expert evidence which took place in this case, to conclude, at the end of the day, that the proximate cause of the ship's loss, even on a balance of probabilities, remains in doubt, with the consequence that the shipowners have failed to discharge the burden of proof which lay upon them."

110. Lord Brandon disavowed the approach of Mr Sherlock Holmes as he was recorded saying to Dr Watson: "How often have I said to you that, when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" for three reasons (at 955H to 956 D):

a) A judge is not bound always to make a finding one way or the other. This is a point "of great importance". The unsatisfactory state of the evidence may make this the only just course for him to take;

b) The dictum can only apply when all relevant facts are known, so that all possible explanations, except a single extremely improbable one, can properly be eliminated;

c) The legal concept of proof of a case on a balance of probabilities must be applied with common sense. If a judge concludes on a whole series of cogent grounds that the occurrence of an event is extremely improbable, a finding by him that it is nevertheless is more likely to have occurred than not, does not accord with common sense.

111. Subsequent and more recent cases confirm the continuing soundness of this approach. For example in O'Connor v The Pennine Acute Hospitals NHS Trust [2015] EWCA Civ 1244 Jackson LJ stated:

"64. It is not an uncommon feature of litigation that several possible causes are suggested for the mishap which the court is investigating. If the court is able, for good reason, to dismiss causes A, B and C, it may be able to reach the conclusion that D was the effective cause. But the mere elimination of A, B and C is not of itself sufficient. The court must also stand back and, looking at all the evidence, consider whether on the balance of probabilities D is proved to be the case. See Nulty v Milton Keynes Borough Council [2013] EWCA Civ 15 at [34] per Toulson LJ and Graves v Brouwer [2015] EWCA Civ 595 at [24] to [30]".

112. In Nulty v Milton Keynes Borough Council (supra) Toulson LJ said this:

"34. A case based on circumstantial evidence depends for its cogency on the combination of relevant circumstances and the likelihood or unlikelihood of coincidence. A party advancing it argues that the circumstances can only or most probably be accounted for by the explanation which it suggests. Consideration of such a case necessarily involves looking at the whole picture, including what gaps there are in the evidence, whether the individual factors relied upon are in themselves properly established, what factors may point away from the suggested explanation and what other explanation might fit the circumstances. As Lord Mance observed in Datec Electronics Holdings Limited v UPS Limited [2007] UKHL 23, [2007] 1 WLR 1325, at 48 and 50, there is an inherent risk that a systematic consideration of the possibilities could become a process of elimination "leading to no more than a conclusion regarding the least unlikely cause of loss", which was the fault identified in The Popi M. So, at the end of any such systematic analysis, the court has to stand back and ask itself the ultimate question whether it is satisfied that the suggested explanation is more likely than not to be true. The elimination of other possibilities as more implausible may well lead to that conclusion, but that will be a conclusion of fact: there is no rule of law that it must do so. I do not read any of the statements in any of the other authorities to which we were referred as intending to suggest otherwise."

113. In Graves v Brouwer (supra) Tomlinson LJ (at paragraph 24) approved that statement of principle, that, provided that all possible causes are known, the ranking of those causes in terms of probability may lead to a safe conclusion that the one considered the most probable was the probable cause of the event, provided that it was not improbable.
114. It is therefore common ground between the parties in principle that in a competing theories case:

a) The court is entitled to engage in a systematic analysis of competing theories and eliminate one in favour of the other;

b) That, in itself, may lead to the conclusion that the preferred theory is more likely than not to be true; but

c) The court must always then stand back and ask itself the ultimate question as to whether or not the preferred explanation is more likely than not to be true.

115. For Mr and Mrs Cooper it is said that the burden of proving that the Polyplumb connector was installed by Thameside/Darenth has been discharged. Nothing by way of alternative competing theory or evidence is sufficiently plausible to displace that conclusion.
116. The forensic exercise in this case has been hampered significantly by the absence of material witnesses, perhaps most obviously:

a) Mr Balola of Signature;

b) Mr Tucny of Ludek.

117. The documentary position has also not assisted in resolving the issues. I have been shown little to no site records, for example, to the extent that they ever existed. Nor has it been possible, for example, to identify with any particularity the timing or nature of works being carried out from any invoicing material that I have been shown.
118. This is thus pre-eminently not a case where all the facts and possible explanations are known. There are significant gaps in the evidence, particularly as to the activities of Signature and Ludek in and around the basin in bathroom 6.
119. Thameside invites me to draw adverse inferences from the failure to call these witnesses on the part of Mr and Mrs Cooper, a submission that I address in section K below. Leaving that to one side, the position is that there are many evidential lacunae. The result has been much speculation; theories have been mooted and abandoned during the course of the trial; new theories have been advanced for the first time in the very closing stages of trial.

G. The witnesses

120. I set out below my general impressions of the witnesses who gave oral evidence.
121. Mr and Mrs Cooper were both genuine witnesses who were careful not to give substantive answers when they had no proper recollection on an issue. The impression that I gained is that they essentially let the builders and designers get on with the job. In Mrs Cooper's words, they were not "hands on", with little presence on site at least until towards the end of the project. The flood and consequent damage to the property have obviously been very traumatic for them and their family.
122. Mr Beer of Ottima was also a careful witness. He is a highly experienced manufacturer of bespoke joinery, including being a high quality cabinet maker. He was familiar with the technical aspects of Ottima's work at the property. He gave evidence as to the design and drawings of the vanity unit in bathroom 6 (which should more properly in fact be described as a medicine cabinet) as they evolved. He described the access panel, a stone niche, in the vanity unit which would allow access to the tap box, and confirmed that the second fix plumbing could not be completed until the basin and vanity unit were in place. He described the second basin, and the steel brackets holding it up. A coach screw, like a bolt head, would be used for bolting the brackets in. So far as he was concerned, the taps were always going to be wall mounted, although he did at one stage have to query the position with Thameside. He had no recollection of any access panel below the basin being made. Ludek would have installed the catches for the access panel with a cordless screwdriver. His evidence was that Ottima did not touch the plumbing at all. Darenth was the only plumber on site. He used Ludek to install Ottima's joinery at the property and confirmed that it was Ludek that installed and removed the basin as it went in and out the first time. I have addressed or will address specific further aspects of his evidence either above or below in the context of the particular issues arising.
123. Mr Evans of MDC was a somewhat edgy witness. He set out the background to the works and a broad chronology, which was incomplete in certain respects. In his witness statement he stated that the basin was installed by 15^th June 2007. After that, in or around July 2007, Signature would have installed the stonework below the basin. It would have been fitted at this stage with an aperture left open below the basin to allow access to the pipework. In cross-examination he could not say when the aperture was created. He (correctly) could not point to a document dated earlier than 21^st August 2007 indicating that such an aperture should be created. He stated that the installation of the access panel did not affect and would not have affected the pipework under the sink.
124. Mr Johnson's evidence in chief consisted of 4 witness statements. He was skilfully and fairly cross-examined. It was made clear throughout that there was no suggestion that Mr Johnson was anything other than an honest witness. Rather he was a witness who had genuinely, though erroneously, persuaded himself post-facto either that he had carried out the plumbing works to the basin in bathroom 6 when he had not at all, or, if he had, that he had not installed the Polyplumb connector. His evidence, and indeed that of Mr Cosgrove, is said to be nothing more than a "figment of retrospective historical imagination". It was suggested that whenever a document emerged, his recollection could be shown to be faulty. And indeed documents did show some parts of his first witness statement to be incorrect. As a result, it is suggested that his evidence is wholly unreliable.
125. There was ample material with which to challenge Mr Johnson's reliability: his first witness statement was materially wrong as to dates. He had also forgotten that he had been abroad on holiday for six weeks from 2^nd April 2007 onwards. He also overstated the amount of time that he spent on site at the property from about 2005 to early 2009. He gave an incorrect impression to the effect that the fixing works were carried out in a continuous manner. In these respects and others, his original evidence was unreliable. The fair point is made that his first witness statement can be taken as his first recollection of events. I have borne well in mind that the mere fact that a witness vehemently believes what he says does not guarantee (or even mean) that his evidence is accurate.
126. But in general terms, having watched and listened to Mr Johnson carefully, I found him to be an impressive and, in other material respects, reliable witness:

a) He readily accepted his original errors and explained that he identified them once he was shown the relevant documentation. I found his explanations for his errors to be genuine and that the making of the errors was not such as to undermine fundamentally his reliability for all purposes. The events in question took place a long time ago. He does not appear to have been shown much, if any, of the relevant contemporaneous documentation to assist him with dates and detail at the time of his first statement, or to have understood the importance or relevance of certain issues. Thus I accept his evidence that he did not understand the importance of sequencing at the time of his original statement;

b) It was he who, shortly before trial, found – by chance – his 2006 diary and his passport showing his movements in 2007. He quite rightly volunteered them up;

c) He made fair concessions without hesitation, for example as to the effect of the facing wall on access to the pipework; on the difficulties of using a spanner in the space available; that the facing wall with its tiling prevented any access to the pipework under the basin. He confirmed that he had never seen the facing wall demolished and had never seen any operatives of Ludek carrying out any plumbing work on site. He made fair concessions in relation to paragraph 11 of his first witness statement, conceding that Darenth had used Polyplumb fittings on some of the waste and soil pipes, which formed part of the plumbing on the project, although he was able to maintain that only HEP₂0 fittings were used by Darenth on pressurised delivery pipework.

127. Perhaps most importantly, he came across as a highly professional plumber who knew the art of his trade with some 25 years of experience at the time of the material events and nothing to hide so far as his work was concerned. He had personally built a "mock-up" to assist the court, which he was eager to use. He appeared at times to be genuinely concerned and anxious that he might be misunderstood as to what happened (on his recollection), and frustrated by the process that he had been put through, in particular at not having had the whole picture before him at the time of his first witness statement. I find that Mr Johnson was not reliable on all dates and timings, perhaps understandably given the passage of time. But he was very clear as to the essence of what he did and did not do as a plumber. A good example is his recollection of what he did on the night of the flood, which I have found to be reliable, as set out in section D above.
128. I set out below my findings on Mr Johnson's evidence on the key issues of whether or not it was he who did the first and second fix of the plumbing for the basin and whether or not, if he did so, he installed the Polyplumb connector or, as he stated, he installed two HEP₂0 T-connectors properly on 2 continuous lengths of pipe. His evidence has been consistently that he did not install the Polyplumb connector.
129. Mr Cosgrove's evidence in chief consisted of three witness statements. He is an experienced mechanical and electrical services engineer. In his first witness statement he stated that all of the piping materials used for the plumbing and underfloor heating works were manufactured by Hepworth Building Products Limited ("Hepworth"). Hepworth was his preferred product for plumbing and underfloor piping and connections, and it was essential to use the best products. In his second witness statement he corrected this unequivocal statement, given that he had by then become aware that in 2008 Polypipe materials were purchased for the soil wastes in connection with the garden room works at the property. But he maintained that he only ever used Hepworth products in the domestic pressurised hot and cold water system. He did not recall ever running out of piping materials during the project. He addressed the sequencing of works and the question of wall mounted over deck mounted taps. He stated that he was unaware until these proceedings of an access panel underneath the basin in bathroom 6 and could not see the reason for one. The reason is normally to provide access to water supply isolation valves in the stud wall. But here, so as to achieve a clean finish, there were no such isolation valve. The valves were in the plant room in the basement, clearly labelled up to allow for instant switching off of the water supply to a particular floor in the event of a leak.
130. Mr Cosgrove was cross-examined in some detail in relation to his chequered trading history. Darenth Southern Limited entered into a creditors' voluntary arrangement on 29^th November 2003 and was wound up on 8^th September 2004. Darenth Southern (UK) Limited was incorporated on 16^th December 1997 and took over the business of Darenth Southern Limited in 2004. On 9^th October 2006 Darenth Southern (London) Limited was incorporated. On 10^th January 2007 a winding-up petition was presented against Darenth Southern (UK) Limited by HMRC and a winding-up order was made on 28^th March 2007 (dating back in the normal way to the date of presentation of the petition). Between 13^th March 2007 and 29^th February 2008 a Nigel Pickett was sole director of Darenth Southern (London) Limited, a position which Mr Cosgrove then resumed until 18^th May 2009 when he resigned and his wife became sole director. Mr Cosgrove indicated that he had resigned in 2007 because he was at that stage prohibited from being a company director. Darenth Southern (London) Limited went into creditors' voluntary liquidation on 17^th August 2010. The total estimated deficiency was £321,090 including PAYE and VAT debts of over £200,000. Thereafter Mr Cosgrove traded as a sole trader (trading as Darenth Southern). He was declared bankrupt in June 2013. In cross-examination, Mr Cosgrove agreed that the early 2007 period was a difficult period for him (although not with suppliers), but said that he never had any problem with the supply of materials for the project at the property (as he had also stated in his witness statements). Mr Cosgrove was also cross-examined in relation to his original unqualified statement that Darenth had never used Polyplumb products on the project, and only purchased Hepworth products.
131. In broad terms I found Mr Cosgrove to be a reliable witness. He was understandably hazy on dates, for example, but clear on the fixing process, for example. He made fair concessions: thus he agreed that it was possible from his point of view that some Darenth plumber other than Mr Johnson did the horizontal fix in bathroom 6, since he himself had not been present at the time (although he was clear that a Darenth plumber would not have installed the straight connectors in the vertical pipes). He agreed that it was an overstatement to say (as he had in his first witness statement) that he had been present on site on an almost daily basis for most of the contract. I deal with specific aspects of his evidence as relevant further below.
132. Mr Gradwell was Thameside's contracts manager on the project at the property and one of Thameside's three directors during the project. He was hesitant at first in the witness box. He was uneasy with the question of Ludek's position as finishing contractor: having stated in bald terms in his second witness statement that Ludek as finishing contractor was never engaged by Thameside as a subcontractor, in oral evidence his position was more subtle. He believed that there was a subcontract entered into between Thameside and Ludek, but only as a mechanism to reduce VAT. Ludek was not a subcontractor in the sense of ever having been under the control or supervision of Thameside.
133. He gave evidence that he did not recall there being any access panel or hatch under the basin in bathrooms 5 or 6 following their completion by 19^th June 2007. He had no recollection of discussing access panels in July and August 2007 but had no reason to doubt that such discussion took place. He confirmed that to his knowledge, whilst there might have been the odd leak, there was no flood.
134. Mr Gradwell then went on to say:

"I cannot remember precisely when, but I do recall that on one particular day, post June 2007, during one of my walks around the site, I noticed that stone below the basin in ensuite 6, had been taken off. I also noted that the wash basin remained in place.

The reason why I noticed the hacked off stone was because I was concerned that there could be damage to other fittings and fixtures in the ensuite and that Thameside would be blamed for any such damage and have to make good the damage.

I specifically remember speaking to someone at Signature Stone informing them that if they were carrying out works and taking off the stone that they should ensure that they protected the wash basin. I was told by the Signature Stone representative that there was no need to worry about damaging the wash basin while removing the stone because the basin was going to be changed. I did not need to take this matter further as such works were not within Thameside's ambit."

135. Mr Gradwell was cross-examined on this, and a head-on challenge to this part of Mr Gradwell's evidence is mounted. I will address the question of whether I accept Mr Gradwell's evidence in this regard. For Mr and Mrs Cooper it is said that Mr Gradwell's evidence is simply wrong.
136. Mr McBryde was a straightforward witness. He was a carpenter working for Thameside. He was foreman/assistant site manager in 2007. He had no recollection of any works for an access hatch under the basin in bathroom 6. He then left the project and returned again. He was in charge of snagging. As already indicated above, he attended the property at the time of the flood. He described how he switched the water off at the pumpset, something which he as a tradesman knew would stop the water.
137. Mr Lynch was a slightly diffident witness, at least at the outset of his evidence. He was site manager for Thameside (when Mr McBryde was not there) from the beginning of 2008. He had no recollection of Thameside being involved in the decision to install an access panel below the basin in bathroom 6, or of seeing the access panel itself. He did not recall Thameside or its subcontractors being involved in its construction (or the making of an access hatch). Once a particular room was completed it was handed over by Thameside to prevent any damage during finishing and furnishing works, although he would still have had access as site manager. Thameside worked from the top of the house down. He stated that he never saw Ludek carrying out plumbing works on site, but they were quite capable of doing so, and worked different hours to Thameside – weekends and late evenings. Thameside had no control over Ludek. They worked as they wanted and independently. He had no recollection of any flood at the property prior to 18^th November 2010.

H. The access hatch and panel

138. It is convenient to deal with the discrete issue of the rectangular access panel that was undoubtedly in place underneath the basin at the time of the flood. There was a rectangular hole filled by a ply access panel which was stone tiled. It was constructed of two access panels, set either side of the waste pipe. The panels were fixed by being fitted into clips fitted into timber blocks which appear to have been screwed into the studwork in fairly rudimentary fashion. The installation of the panels was finally completed in about June/July 2008.
139. When, how and for what purpose the hatch for the panel was created and the panel fixed has become an important issue in the case. If the hatch did not exist before 19^th June/3^rd July 2007, then the stonework below the basin had to be removed at some point to create it after that, with the possibility, submits Thameside, of damage to the pipework. If the hatch did exist before then, then there was no need for any stone removal works thereafter.
140. Thus much emphasis is placed for Mr and Mrs Cooper on the access hole and the timing of its creation. The suggestion advanced for the first time in closing was that the access hole had a clear purpose – namely to give access to the straight connectors that had by then been put in place. This is said to be the obvious inference to be drawn as to the purpose of the hole and panel. Indeed, it was through the access panel that access to the connectors was gained on the night of the flood. The access panel cannot have been installed for the purpose of access to the waste pipe, since the evidence of Mr Cosgrove and Mr Johnson was to the effect that they did not need an access panel. Even if it was for the purpose of gaining access to the waste pipe the hole would have been created deliberately before 3^rd July 2007 at the latest. On this analysis, the straight connectors must have been in place by 19^th June/3^rd July 2007. Events thereafter are an irrelevance. The straight connectors could not and would not have been installed as a result of damage to the pipes after 19^th June 2007, for example.
141. I cannot accept this new theory. The suggestion that the access hatch/panel was put in specifically because the straight connectors had been put in place was not put to any of the witnesses. But ignoring that, there was no need for access to the straight connectors: they were not valves. Moreover, the logical consequence of the submission, given that an access hatch and panel was also installed in bathroom 5, is that there must have also have been straight connectors installed into the pipework for the basin there. This was never suggested to Mr Cosgrove or Mr Johnson, and would have involved Mr Johnson (or someone else at Darenth) carrying out twice what Mr Johnson saw as a wholly unnecessary exercise (or the unlikely event, on a hypothesis advanced for Mr and Mrs Cooper, of pipe being cut too short in both bathrooms).
142. In my judgment the strong likelihood is that the access hatch and panel were created after the photograph of 3^rd July 2007 (which I treat as inconclusive on the point) was taken:

a) Not a single drawing for bathroom 5 or 6 shows an access hatch or panel below the basin. An access panel was shown in the vanity units. Without an express instruction before 3rd July 2007, of which there is no evidence at all, the hatch and panel would not have been created by then;

b) The first document to mention the need to fix stone below the basin in bathroom 6 is dated 15^th July 2007 (some 6 days after Signature was on site on 9^th July 2007). Express reference to an access panel below the basin in bathroom 6 is first made on 21^st August 2007;

c) This is consistent with the question of access for maintenance generally at the property being something of an afterthought, perhaps triggered here by someone seeing the fully tiled stonework right up to the basin in bathroom 6 in early July 2007. The minutes of a site progress meeting on 1^st July 2008 record that design had been prioritised over practicality/access for maintenance;

d) Mr Cosgrove's evidence, which I accept on this issue, is that he was never aware of an access hatch or panel below the basin in bathroom 6;

e) Mr Johnson was very clear that there was no hole below the basin when he carried out the second fix. The wall was stone clad up to the basin – a finished wall. I accept his firm evidence on this issue;

f) In particular, Mr Johnson's unchallenged recollection of the second fix is important in this context. He stated that as part of the second fix he placed a chrome flange over a horizontal (first fix) pipe and placed it up against the tiling. The flange, which can be seen on photographs, allows for any discrepancy in the cutting and fixing of the tiles around the chrome pipe. He would not have been able to do this if there had been an open hatch without an access panel in place. This would be a remarkable embellishment of recollection if it were not true. I accept his evidence on this issue.

143. In summary, therefore, I find that there was no access hatch or panel below the basin at any time before 3^rd July 2007. A hatch was created after that date, and the panel not in place and completed until July 2008.
144. It follows that stonework below the basin in bathroom 6 needed to be removed after 3^rd July 2007 in order to create the access hatch and panel. As set out later below, I also accept Mr Gradwell's evidence that he saw the stone panel below the basin being hacked off by Signature's stone fixers, which supports this conclusion.

I. Did Mr Johnson (or another Darenth plumber) probably install the Polyplumb connector?

145. This question raises the following sub-issues:

a) Did Mr Johnson do the plumbing to the basin in bathroom 6?

b) If so, did he install the Polyplumb connector?

c) If not, did another Darenth plumber do the plumbing in bathroom 6?

d) If so, did that other plumber install the Polyplumb connector?

Did Mr Johnson do the plumbing to the basin in bathroom 6?

146. For Mr and Mrs Cooper it was put to Mr Johnson that either he did not, or may not have done, the first and/or second fix plumbing in bathroom 6 at all. Someone else at Darenth was, or may have been, responsible for it. Both Mr Cosgrove and Mr Johnson gave unchallenged evidence that Mr Johnson was the "foreman" plumber when he was on site. No Darenth plumbers other than Mr Johnson have been identified by name or by dates on site (save for certain periods in 2008 when records suggest that two and sometimes three Darenth plumbers were on site).
147. To resolve this issue, it is necessary to make certain findings as to the likely sequence of events. The first fix plumbing involved the installation of horizontal and vertical piping for hot and cold water. The second fix plumbing involved fitting the spout and taps once the wall had been tiled.
148. Mr Cosgrove and Mr Johnson were both clear that the vertical pipes could not be installed until the tapbox was available. The tapbox was not available as at 13^th November 2006 when Mr Cosgrove wrote his letter of 13^th November 2006 referring to "… all of our services are in position".
149. For Mr and Mrs Cooper heavy reliance is placed on this letter. It is suggested:

a) That the letter shows that both horizontal and vertical pipes had been laid by 13^th November 2006;

b) By reference to Mr Johnson's 2006 diary, that Mr Johnson could not have carried out the laying of the horizontal or vertical pipes.

150. I reject the suggestion that both horizontal and vertical pipes had been installed by 13^th November 2006. I accept Mr Cosgrove's evidence that when he referred to "all of our services" he was referring to the horizontal first fix works only. Without the sanitary ware it was impossible to progress the plumbing further. Not only was he clear on this in his evidence, it follows as a matter of logic. For Mr and Mrs Cooper the fair point is made that in his first witness statement, Mr Johnson stated that he cut both the horizontal and vertical pipes first. But this was when the installation of both horizontal and vertical pipes and the tap box was being treated as a single continuous exercise. And as already indicated, I accept Mr Johnson's explanations for the inaccuracies in his first witness statement.
151. Thameside's letter of 15^th December 2006 to MDC confirms that installation works could not commence without elevational drawings setting out the correct positioning, including control brassware. Mr Beer's letter of 10^th January 2007 also confirms that the vertical pipes were yet to be installed. The reference to "plumbing before stone can be fitted" in Mr Beer's letter of 10^th January 2007 also confirms that vertical pipes had yet to be fixed as at that date. Mr Cosgrove's letter of 23^rd April 2007 refers to the majority of the sanitary was having been "piped up" at that stage.
152. Thus the first fix was carried out in two stages. I find that as at 13^th November 2006 only the horizontal fixing of pipes had been done.
153. I find that there was every opportunity for Mr Johnson to have done this horizontal fixing and accept his evidence that it was he who did the laying of the horizontal piping under the basin in bathroom 6 by 13th November 2006. It is not clear precisely when he would have done it. In his second witness statement he referred there being "some considerable time" between horizontal and vertical fix, which in oral evidence he said meant anything up to a month or possibly slightly over. I do not consider this a firm or reliable estimate: as already indicated, Mr Johnson did not demonstrate accuracy on timings or dates. As he said, his 2006 diary was not complete in every respect – he stated that he was "not fantastic" at keeping up his diary; it was admittedly not 100% accurate. To his credit, Mr Johnson was not prepared to say with any certainty that the entry on 22^nd June 2006 was an entry relating to his works in bathroom 6. In cross-examination Mr Johnson stated that he did not know if that was the date when he did the horizontal first fix. He did not think that it was a reference to that. In re-examination Mr Johnson repeated that he could not be specific as to exactly what the entry referred to in terms of which bathroom. But running services in studwork meant running hot and cold water pipes through studwork.
154. Mr Johnson stood firm in his evidence:

"Nobody else put in the horizontal piping. I put it in."

155. Given his recollection as confirmed in the witness box, which I accept as not only genuine but accurate despite strong cross-examination on the point, I conclude that it is likely that Mr Johnson laid the horizontal first fix. Amongst other things, there would be no reason for Mr Johnson to lay claim to carrying out work personally which he did not in fact do – indeed, one would have thought quite the opposite, given subsequent events. It is clear that Mr Johnson was on site in June and on 25^th September 2006. The horizontal fixing was not a complex or time-consuming task, as Mr Johnson said (and partly demonstrated) in the witness box:

"It's not something that takes a long time, it's just a pain drilling it all, but to pull the pipe through from one end of a bathroom is…..you know, it's not a difficult job."

156. The tapbox arrived after Mr Cosgrove placed his order on 13^th February 2007. There was then ample opportunity for Mr Johnson to complete the (vertical) first fix before going on holiday on 2^nd April 2007, as he said he did. Reference was made in the course of submissions to Mr Johnson having "professional pride". Again, I can think of no reason why Mr Johnson would accept responsibility for works that he did not do. The existence of ply fitted by Ottima (referred to in Thameside's letter of 4^th April 2007) would not have posed any impediment to him doing the vertical piping before 2^nd April 2007. Mr Cosgrove's letter of 23^rd April 2007 confirmed that by that date the majority of the sanitary ware had "been piped up". It is right that other plumbing works were being done in bathroom 6 when Mr Johnson was away. But none of them appear to have related to the plumbing under the basin. Nor is there any suggestion that Mr Johnson, the foreman plumber, was told on his return from holiday that his plumbing works had been touched or altered in any way, which might have been expected, had it happened.
157. As already indicated in section H above, I also accept the evidence of Mr Johnson that he carried out second fix on his return from holiday in mid-May 2007. The instruction for second fix was confirmed on 19^th June 2007, and can be seen in place in the photograph of 3^rd July 2007.
158. I therefore conclude that, on a balance of probabilities, it was Mr Johnson, and not another plumber or plumbers from Darenth, who carried out the first and second fix plumbing for the basin in bathroom 6.

If it was Mr Johnson, did he install the Polyplumb connector?

159. On my finding that it was probably Mr Johnson who carried out the relevant plumbing works, the question then is whether or not he installed the Polyplumb connector on the hot water pipe under the basin in bathroom 6, or whether, as he says, he installed two continuous pipes without connectors.
160. Mr Johnson gave compelling evidence on this issue. From his first witness statement onwards he has said that he is certain that he did not install the Polyplumb connector and that he joined a piece of pipe long enough to reach the tap box connections. In his words (from paragraph 30 of his first witness statement):

a) He was working on a bare stud wall with no fixtures or fittings in place;

b) All he had to do was connect a length of pipe between the T-joint and join a piece of pipe long enough to reach the tap box connections. He used a single length of pipe for each of the hot and cold water supplies;

c) There was simply no reason for him to make the length of pipe shorter. Connecting two different lengths of pipe would not only result in additional work and materials but would not be good practice;

d) If for some reason he had misjudged the length of pipe needed, he would simply have discarded those lengths of pipe and cut another piece. He would not have pieced together two small pieces of pipe with a joint connection and then repeated the same for the other piece of pipe. Such small pieces of piping are not used and are always thrown in the skip. There was no shortage of pipe material on site as it was drawn from a large 50m coil.

161. His evidence on this in cross-examination did not waiver.
162. I find his evidence to be supported by the following facts and matters:

a) This was a very poor piece of plumbing work indeed on a project which Mr Johnson knew was to be of the highest quality and standard. There was no sensible plumbing reason for the use of connectors, let alone the use of a second hand fitting. In opening, it was described for Mr and Mrs Cooper as "a piece of unbelievably shoddy plumbing". Yet Mr Johnson is and was a highly competent and experienced plumber. Mr Evans was clear that there were no problems with or complaints about Darenth's work on the project. Thameside has continued to use Darenth on other projects. It is very difficult to associate Mr Johnson (or any other Darenth plumber) with such a piece of work. He is also accepted on all side as being an honest man. If he had made such a mistake, my assessment is that he would simply have admitted it;

b) No credible reason has been identified for Mr Johnson (or any other Darenth employee) to cut lengths of pipe that were too short, necessitating the use of connectors. The theory advanced has been that there was uncertainty as to whether or not the taps were to be deck mounted or wall mounted. Mr Beer recalled no discussion at any stage of deck mounted taps. From his point of view, the taps were always to be wall mounted. Mr Johnson, the relevant individual on my findings, at no time thought that the basin in bathroom 6 was to have deck mounted taps. This was clear to him from the drawings, and also from the size and configuration of the bathroom, which was small and very narrow. The designers made a mistake at one stage, but Mr Cosgrove picked that up and obtained clarification that it was indeed a mistake. Even if there was a period when Mr Cosgrove had to query the position on 1^st February 2007, there was only a short period of uncertainty. And even if he had a doubt, he never positively believed that deck mounted taps would be used. The incorrect fittings were returned not used, as Mr Evans confirmed;

c) Even if the pipes were cut too short, Mr Johnson appeared genuinely unable to understand why the solution would be to insert straight connectors. He would just have started again to cut longer lengths of pipe, cheaply and readily available. He was working on an open stud wall. I am not persuaded that anything in Darenth's financial history undermines the evidence of both Mr Johnson and Mr Cosgrove that there was never any shortage of piping materials. Mr Cosgrove was clear that was never any shortage. Nothing in his conduct on the project in early 2007 suggested that he (or Darenth) was in turmoil: rather the contrary, his correspondence at that time appears careful, detailed and prompt;

d) The fact that the faulty joint was a Polyplumb connector, not a HEP₂0 connector, suggests that the work was not that of Darenth. Whilst both Mr Cosgrove and Mr Johnson were incorrect in saying that Darenth did not use Polyplumb products anywhere on site, there is no evidence to suggest that they were wrong in maintaining that none of Darenth's work on the pressurised hot and cold water installation system involved Polyplumb products, let alone second-hand Polyplumb products.

163. As for Mr Johnson's failure to deny to Thameside on the night of the flood or in the immediate aftermath that he was responsible for installing the Polyplumb connector, Mr Johnson's evidence was that that was not his focus at the time. He did not give any thought to it. He just focused on dealing with the plumbing in what was a very stressful environment. He had been working all day and been called out at night from home in Surrey. It is not clear on the evidence whether he realised on the night that a rogue joint had been involved. In any event, Mr Johnson was clear that in the immediate aftermath he told Mr Cosgrove upon his return from holiday that the joints in the pipes were "rogue". He said then that matters went "oddly quiet". Mr Cosgrove confirmed that Mr Johnson had told him that the Polyplumb connector had not been installed by him.
164. This was a large flood, and both Mr Johnson and Mr Cosgrove realised the potential implications for Darenth. But in circumstances where:

a) they were not being approached by Thameside (or anyone else), to provide any information or answer questions in relation to the incident;

b) Mr Johnson had told Mr Cosgrove, for whom he had been working at the time, that he had not installed the Polyplumb connector;

c) Mr Cosgrove had informed his insurance brokers of the incident and was told not to make any statements in respect of the incident,

165. I do not therefore consider that the omission to do more in the immediate aftermath means that Mr Johnson and Mr Cosgrove's version of events is undermined.
166. As for the early admissions by Thameside's insurers/loss adjusters that Darenth was responsible for the installation of the Polyplumb connector, they may be seen as understandable in the sense that Darenth was the sole sub-contractor responsible for the plumbing works on the project. But they appear to have been made on the basis of assumption alone and without resort to Mr Johnson (or Mr Cosgrove).
167. Fundamentally, there is no suggestion that Mr Johnson (or Mr Cosgrove) have ever admitted installing the Polyplumb connector. Nor is there any suggestion that they were questioned in the context of this claim before November/December 2014, surprising though that may be.
168. In these circumstances, I reject the invitation for Mr and Mrs Cooper that at the time of the flood neither Mr Johnson nor Mr Cosgrove thought that it could be said that the failed joint was not Thameside's fault.
169. For all these reasons, and subject to the further considerations below, I would find on a balance of probabilities that when Mr Johnson did the plumbing to the basin in bathroom 6, he did not install the Polyplumb connector.

J. Possible alternative explanations for the installation of the Polyplumb connector

170. An intrinsic part of the forensic exercise has been a consideration of whether or not it is possible that someone other than Mr Johnson or Darenth could have installed the Polyplumb connector. If the answer is "no", then clearly a conclusion that it was not Mr Johnson or Darenth is thrown into doubt (if not made impossible).
171. I have come to the clear conclusion that on the state of the evidence before me it is at the very least possible that someone other than Darenth, such as Ludek or Signature in particular, installed the Polyplumb connector.
172. The first realistic opportunity was after 3^rd July 2007 when the photograph of the basin in bathroom 6 was taken but before 15^th July 2007 when there is reference to fixing stone below the basin in bathroom 6. During that period, the access hatch may have been created in both bathrooms 5 and 6, necessitating the taking down of the stone wall beneath each basin. Signature was on site on 9^th July 2007. Mr Johnson said that it would take 30 minutes to take the wall down if one rushed. In a non-emergency situation, one could get a grinder, cut out as necessary and chip out the middle. This would take two or three hours, according to Mr Johnson.
173. As already set out above, Mr Gradwell gave evidence that, during one of his walks around site after June 2007, he noticed that stone below the basin in bathroom 6 had been taken off. I accept Mr Gradwell's evidence in this regard as reliable. He had a very specific memory. When it was suggested to him that what he had in fact seen was Mr Balola putting the stone onto the ply access wall, he said:

"Definitely not. The debris and the way the stone was smashed with a hammer…"

174. He went on in clear terms to say that the whole wall beneath the basin came off. The stone was not expensive in the context of how much stone there was in the house. When it was put to him that he was wrong, he said that was what he saw. His responses in the witness box were both spontaneous and convincing. I can see no possible motive for fabrication, and it was not put directly to him that he was lying, and his evidence has been consistent. He has not been in touch with Thameside since he left the company.
175. Mr Gradwell's reliability is attacked by reference to the following matters:

a) The fact that he stated unequivocally in his second statement that Ludek was never engaged by Thameside as a sub-contractor. As appears in section L below, in fact, as Mr Gradwell accepted, the position is more nuanced than that. Two points can be made: i) this issue has nothing to do with seeing the demolition of the wall in bathroom 6 and ii) the statement was made the day before his oral evidence in response to the late positive case mounted for Mr and Mrs Cooper that Ludek as finishing contractor was Thameside's subcontractor. Although Mr Gradwell did of course sign and verify the statement, it smacks of being drafted over-enthusiastically by lawyers and in a rush during trial without full consideration of the relevant documents. When Mr Gradwell was taken to those documents, he readily explained the subtler position that there was a sub-contract between Thameside and Ludek in around July 2008, but it was only a mechanism;

b) The fact that he incorrectly suggested that Thameside was denied access to the property from the end of 2007 through 2008. Mr Lynch said that as site manager, he did have access if he needed it. This point again does not strike at the heart of the matter: it is clear that there was handover of rooms as they were completed by Thameside to Ludek or for snagging purposes;

c) The fact that he allegedly downplayed his position within Thameside as director. I do not consider this to be a fair criticism. It was clear from Mr Gradwell that he did not consider himself a main player in Thameside. He was a director, but his role was really that of contracts manager. He held only 5 out of 100 shares in Thameside. Nor am I impressed by the criticism of his failure to mention what he saw in bathroom 6 to Thameside's insurers. I accept that his evidence that he was not involved in the arguments being advanced on behalf of Thameside. Mr Harris was dealing with that side of things. Mr Gradwell's role was just to carry on with Thameside's projects.

176. It is very possible that, in the course of the exercise witnessed by Mr Gradwell, Signature and/or Ludek damaged the pipework underneath the basin. It is equally possible that either or both of them then attempted to repair the damage with the installation of the two straight connectors, including the Polyplumb connector. The lower part of the pipework was replaced because the upper part was more difficult to access.
177. Various additional points (beyond the challenge to Mr Gradwell's evidence) are raised against this possibility:

a) The lack of documentary record of any instruction to demolish the wall. But if it was a necessary part of creating the hatch, this absence is not so telling. And the documentation before me appears incomplete;

b) The lack of any evidence of a claim for payment for such work. As already indicated, it is not clear precisely what was charged for and when, but in any event the absence of a claim for repair works at least is consistent with damage being caused through someone's fault (and so not claimed for). And again I am not convinced that all the documentation is available;

c) The fact that no other witness than Mr Gradwell saw the wall down. This is not surprising. The bathroom was a small room at the top of the property;

d) The lack of any evidence of a flood taking place. All the witnesses have been clear that they were never aware of a flood as such. But i) the system may not have been energised ii) even if it was, the entire system could have been isolated by use of the pump set, or the second floor system could have been isolated by use of the individual clearly labelled isolation valves in the plant room described by Mr Cosgrove. This could have been done before the works were carried out, or immediately upon the damage being caused. The damage would have occurred in the presence of at least one tradesman who could also have taken steps to clear up and minimise any flooding;

e) The fact that two pipes were compromised. This merely suggests that both pipes may have been cut to move them or damaged;

f) The fact that Signature was not a plumber. This does not rule out the possibility of Signature installing the Polyplumb connector: the job was relatively simple. The fact that it was done so incompetently suggests in any event that it was not carried out by a professional plumber. Additionally, it appears that Signature and Ludek worked closely together. If there was some sort of incident, Ludek may have helped Signature out;

g) The fact that there is no evidence of anyone seeing the wall down in bathroom 5. This is correct. The focus of the trial and evidence has been very much on bathroom 6. But the wall in bathroom 5 may have been taken down after Mr Gradwell saw the wall down in bathroom 6.

178. There is also a second realistic opportunity which comes earlier in the day, when the steel brackets for the basin in bathroom 6 were being installed and the studwork was open. Mr Beer's evidence was that Ludek installed the brackets. The chronology suggests that this took place around 1^st May 2007 with completion of the task by 15^th June 2007. The brackets were substantial and required fixing with bolts. Albeit not with any particular enthusiasm, Mr Beer agreed that in the course of this installation work, although he could not see any reason why, it might have been thought necessary to move the pipes underneath the basin. It is possible that someone cut the pipes to move them, then reinstating them with straight connectors and replacement lower piping. Access to the upper piping would have been more difficult. Mr Beer also agreed that in the course of the installation process damage to the pipes might have been caused. Again, this might have resulted in a replacement exercise involving the Polyplumb connector.
179. Finally, there is a suggestion that the pipes could have been damaged when the two sections of access panel were installed in 2008, one on either side of the waste pipe, fitted on to magnetic catches themselves fitted on wooden blocks, probably with the use of a cordless screwdriver. The blocks and clips are very close to the pipes. It is posited that the pipes may have been cut deliberately to move them or damaged inadvertently. The difficulty with this theory is the fact that, as indicated above, the pipe above and below the connectors is of different coil. It is common ground that the wall was fully in place at this stage. Mr Beer thought that access might be possible via the hatch in the bottom of the vanity unit, so as to replace the top part of the pipe. Mr Johnson was clear that in his view this would have been "extremely difficult, if not impossible." Alternatively, it is suggested that there would be access if the basin had been removed at this time. But Mr Johnson was clear that, even though removal of the basin would reveal the pipework, it would not in any meaningful way allow achievement of the ultimate result. Finally, it is suggested that there could have been access from bedroom 4 if its studwall was not covered at the time. (A "pleading" point was taken against Thameside on this: but, fairly read, I do not think that paragraph 9I.5 of the Re-Amended Defence does more than deny access within bathroom 6 with the facing wall in place.) But there has been no evidence as to the state of the wall in bedroom 4. On the evidence before me, if this third scenario is a possibility at all, it is a very faint one.
180. For these reasons, on the state of the evidence before me, I find that there are at least two real possible alternative explanations for the installation of the Polyplumb connector that do not involve installation by Mr Johnson (or anyone at Darenth). I do not need to, nor do I, make a positive finding as to which of these possibilities is the most likely, or the likely, mechanism. It is sufficient for me to find that there are these real possibilities. To this extent then, the mystery remains unsolved.
181. Taking the evidence then in its totality, I find that neither Mr Johnson nor anyone at Darenth was responsible for the installation of the Polyplumb connector.

K. Possible adverse inferences

182. I have reached the above conclusions without reliance on any adverse inference being drawn against Mr and Mrs Cooper as a result of any failure to call Mr Balola or Mr Tucny.
183. The law in relation to the drawing of inferences was well-established in Wisniewski v Central Manchester Health Authority [1998] PIQR 324 at 340 (per Brooke LJ):

"(1) In certain circumstances a court may be entitled to draw adverse inferences from the absence or silence of a witness who might be expected to have material evidence to give on an issue in an action;

(2) If a Court is willing to draw such inferences, they may go to strengthen the evidence adduced on that issue by the other party or to weaken the evidence, if any, adduced by the party who might reasonably have been expected to call the witness;

(3) There must, however, have been some evidence, however weak, adduced by the former on the matter in question before the court is entitled to draw the desired inference: in other words, there must be a case to answer on that issue;

(4) If the reason for the witness' absence or silence satisfies the court, then no such adverse inference may be drawn. If, on the other hand, there is some credible explanation given, even if it is not wholly satisfactory, the potentially detrimental effect of his/her absence or silence may be reduced or nullified".

184. As for Mr Balola, Mr Cooper stated that he had engaged Signature since the flood, not only at the property, but also for example approximately one or two years ago to put a new personal bathroom in his office. Mr Cooper could not say why Mr Balola was not being called as a witness.
185. As for Mr Tucny of Ludek, Mr Cooper stated that he had been in contact with Mr Tucny as recently as some six months ago. Mr Tucny had called Mr Cooper asking what he should do about questions he was being asked by email about the property. Mr Cooper told Mr Tucny to assist where he could. He could not say why Mr Tucny was not being called as a witness.
186. Thameside invites me to draw the inference that Messrs Balola and Tucny would have given evidence adverse to the claim. There was clearly a case to be answered by reference to the works of Signature and Ludek. No evidence was adduced as to why they were not called as witnesses.
187. For Mr and Mrs Cooper it is said that Signature is now in creditors' voluntary liquidation. There was only very weak evidence implicating Signature and Ludek. There are many possibilities as to why the witnesses were not called, including non-cooperation.
188. Giving Mr and Mrs Cooper the benefit of the doubt as to the reasons why Signature and Ludek were not called to give evidence, I decline to draw the inference that Mr Balola and/or Mr Tucny have not been called as witnesses because their evidence would have been adverse to the claim. However, the lack of any evidence from them has weakened the merits of the claim, as indicated elsewhere in this judgment.

L. The position of Ludek

189. Although my conclusions above render the issue irrelevant, I address briefly the dispute between the parties as to whether or not, after being appointed finishing contractor in 2008, Ludek acted as a servant or agent of Thameside. It would only be relevant had I found that the Polyplumb connector was installed by Ludek after July 2008, which I have not. No positive case was pleaded on behalf of the Coopers to the effect that Ludek was a sub-contractor of Thameside, although it was not expressly admitted that Ludek was not a sub-contractor of Thameside. However, it became clear during the course of oral openings at least that it was being submitted for Mr and Mrs Cooper that Ludek, when appointed as finishing contractor in 2008, was a sub-contractor for Thameside.
190. I have been shown only a limited amount of documentation in relation to Ludek's engagement as finishing contractor. Mr Cooper's "best recollection" was that when Ludek came onto the scene as finishing contractor, Ludek "came under the Thameside contract". He said this because he believed that Thameside had paid Ludek. Mr Beer's evidence was that Ludek was contracted either to Thameside or Mr Cooper direct for the purpose of acting as finishing contractor. Mr Evans (of MDC) was clear that Ludek was acting as finishing contractor employed directly by Mr Cooper. However, Mr Gradwell (of Thameside) said otherwise when taken to the following documents.
191. Minutes of a progress meeting on 1st July 2008 recorded:

"2. Contract Procedure. [MDC] explained that it had been agreed that all sub-contractors would now be under the control of Thameside…and that everyone must report to [Thameside] about their programme on site, the information outstanding and any construction difficulties which they faced…

5. Ludek Build. Ludeck Tucny was introduced to the meeting as the finishing contractor for the works…..[Mr Tucny] had..to produce a price for acceptance by [Mr Cooper]. He will send this through to [Sheldon Studios] to check the content and to [MDC] for passing on to [Mr Cooper]. The intention is that [Thameside] will hand over areas of the site to [Mr Tucny] who will then see that area through to completion."

192. On 28^th July 2008 MDC forwarded to Mr and Mrs Cooper a quotation from Ludek for the first and second floors of the property in the sum of approximately £92,000 excluding VAT. It excluded works to the landing, the cost of wallpaper and carpets and supply only joinery costs (by Ottima). In relation to the ensuite bathroom to bedroom 6, a sum of £2,165 was quoted for: cutting a hole for speakers; plasterboarding/skimming/filling; fitting bathroom accessories; decorating; ironmongery; polishing; covering and cleaning and "unexpected/extras". As a general description point, Ludek stated that the completion of plumbing works would be done by "Plumber Contractor".
193. The following day, on 29^th July 2008, MDC emailed Thameside and Ludek, copied to others, to confirm that Mr and Mrs Cooper were happy to proceed with Ludek's proposed works and pricing as submitted:

"Accordingly please can you formalise Ludek's appointment and agree the programme going forward in order to get Ludek on site without delay."

194. Mr Gradwell stated that this was a request to Thameside to take Ludek on as sub-contractor, and that he believed that that is what happened. He went on to say that this was a "mechanism" to save VAT for Mr Cooper.
195. This appears to be confirmed by emails between MDC and Mr Cooper on 28^th July 2008. When presented with the quotation from Ludek, Mr Cooper asked MDC what the VAT percentage was. MDC replied by saying that if it went through the JCT contract, "the VAT (ie paid through Thameside) it would be 5%, if not it will be 17.5%."
196. Come 21^st August 2008 Mr Tucny was emailing Mr Harris of Thameside recording receipt of £20,000 and asking for £10,000. On 11^th September 2008 he was querying numbers on a payment certificate from Thameside and chasing payment on a fortnightly basis:

"Our company is not established for monthly payments and this was the reason why I agreed with Darren [of Sheldon Andrews] that only fortnight payments will allow me to step in to the Redington and work there…"

197. Later the same day he wrote to Mr Harris stating that Ludek had also agreed with Mr Harris and Mr Gradwell that all payments would be 60% labour and 40% materials. Mr Harris responded to Mr Tucny's queries on the numbers later the same day, also emailing MDC.
198. On 11^th September 2008 Mr Darren Gayer of Sheldon Andrews emailed MDC confirming that fortnightly payments had been agreed and asking what to do. MDC responded by telling Mr Gayer to speak to Mr Cooper:–

"…if Marcus wants to take it out of the responsibility of Thameside and the contract that is fine. I will do whatever instructed. The downside is that neither Thameside nor ourselves have any control over the situation but if you can deal with it then that is fine (if Marcus agrees).

199. Mr Gradwell stated that the sub-contract with Ludek was not terminated. As finishing contractor, Ludek was a sub-contractor of Thameside. However that contract was only as a mechanism for reducing VAT for the Coopers. Ludek was never a sub-contractor in the sense of Thameside exercising any control or supervision of it.
200. In July 2009 Mr Tucny emailed MDC asking for payment in stages between July and December 2009. He needed cash flow. MDC replied, confirming that Thameside would be responsible for £25,000 to be paid on 31^st July 2009. On 31^st August 2009 payment would be made for whatever was outstanding in respect of the latest set of works by either Mr Cooper or Thameside or both as directed by MDC. Providing the final account was agreed, Ludek would be paid any outstanding balances by 11^th September 2009.
201. The evidential picture is far from clear. It appears that Ludek was under some sort of contractual arrangement with Thameside by about August 2008, but the terms of that agreement are uncertain. It is not at all clear to me that, if Ludek was responsible for the installation of the Polyplumb connector in or after August 2008, it was acting under that agreement. Indeed, Ludek's quotation suggests that it would not have been, given the express exclusion of plumbing works. It seems to me more likely that Ludek would have been acting under the "old" arrangement of working for Ottima/Signature. Had I therefore made a positive finding that Ludek was responsible for the installation of the Polyplumb connector at some stage after appointment as finishing contract, I would have concluded that it had not been established, on a balance of probabilities that it was then acting as the servant or agent of Thameside under the JCT contract.

M. Conclusion

202. It is undoubtedly right that the claim against Thameside had very promising prospects at the outset of these proceedings:

a) It has always been common ground that the works under the JCT contract included the installation of the pipework beneath the basin in bathroom 6;

b) It has always been common ground that Darenth was Thameside's plumbing sub-contractor under the JCT contract and the only contracted plumber on site;

c) Thameside admitted that Darenth installed the Polyplumb connecter.

203. The defence rested essentially on causation arguments, all of which have now been abandoned.
204. Matters have, however, moved on very significantly since then. Most obviously, Mr Cosgrove and Mr Johnson have been asked on behalf of Thameside and its insurers to provide their response to the claim, and in particular their response to the allegation that Darenth was responsible for installing the Polyplumb connector.
205. For the reasons set out above, standing back, and looking at all the evidence, I do not consider that it has been proved that Darenth or any other servant or agent on behalf of Thameside installed the Polyplumb connector. In particular, I find that it is unlikely that Mr Johnson or anyone else at Darenth carried out that installation. Against an incomplete evidential picture, it is ultimately the combination of the credibility of Mr Johnson as to the essence of what he did and the real possibility that another non-Darenth tradesman on site performed the highly incompetent installation that leads me to the conclusion that the case against Thameside has not been made out on a balance of probabilities.
206. The claim will be dismissed. I invite the parties to draw up an order reflecting the above, and to agree all consequential matters so far as possible, including costs.