HT-2022-000311 & HT-2022-000254 - [2024] EWHC 3179 (TCC)

In relation to the FPA, Click St Andrews denies any breach of duty.

It is convenient to start with the issue of what protection was provided and ought to have been provided to the roof during the carrying out of these works. It might be thought that some protection to the roof would always be required given the vagaries of British weather and I did not understand Mr Emmett to suggest otherwise.

In its Defence, Click St Andrews said this:

“In preparation for the installation of the modular units and prior to the Removal of the Temporary Roof, St Andrews laid a sacrificial waterproofing layer comprising a Visqueen waterproofing membrane to provide protection from average rainfall during the period of the removal of the Temporary Roof and the installation of the modular units (“the Membrane”). The Membrane was not installed in anticipation of a one in 30-year weather event which included far in excess of above average rainfall.” (my emphasis)

Put somewhat colloquially, Click St Andrews’ position is that that membrane was proper and appropriate protection against normal rainfall. The actual rainfall on 25 July was exceptional and, as they said to the leaseholders at the time, the protection was overwhelmed by the torrential rain.

Click St Andrews further stated that, the tin hat roof had already been removed when the first yellow weather warning was given. In light of the terms of the yellow weather warnings, it was reasonable to continue with the works. The amber warning was only given on 25 July 2021. At that point installing the modules offered the best means of protection.

The claimants submit that it was negligent (and in breach of clause 5.2) to remove the tin hat roof at any time during the week commencing 19 July given the prediction of rain in the yellow weather warnings.It is, it is submitted, no answer to that to say that the rainfall on 25 July was particularly and unexpectedly severe. The yellow weather warnings were sufficient to alert a competent contractor to risks of proceeding with the works at the coming weekend. Further, in his 12^th witness statement, Mr Creasey, the claimants’ solicitor, had pointed out that, as early as 20 July 2021, the weather forecasts on the BBC and ITV lunchtime news had predicted storms across London over the weekend. In any case, although the rainfall over the course of one hour was exceptional, the volume of rainfall was not.

Further, and in any event, as I have said, the claimants submit that the protection to the roof was inadequate. If Click St Andrews was going to proceed with the works when there was a risk of rainfall and/or a risk of rainfall to the extent indicated by the yellow weather warnings, it ought to have provided protection sufficient to protect the building in those circumstances. It did not. There was no Reply to Click St Andrews’ Defence but in submissions the claimants said that, other than the tin hat roof, the extent of the weatherproofing measures implemented by Click St Andrews was tarpaulin sheets hung over parts only of the scaffolding, so not covering the whole of the roof, and a Visqueen damp proof membrane at roof level.

The claimants’ solicitors obtained an e-mail from the suppliers of the tarpaulin, Premier Tarpaulins, stating that they received two orders for tarpaulin from Click St Andrews on 26 July 2021 and a further order on 2 August 2021. In other words, these tarpaulins were not supplied until after the water ingress on 25 July 2021. I do not understand Click St Andrews whether in the Defence or in submissions to place any significant reliance on the tarpaulins as weatherproofing for the roof.

So far as the Visqueen membrane is concerned, there was a dispute of fact as to what was installed. As I have said, the defendants’ pleaded case was that Click St Andrews installed a sacrificial waterproof membrane, that is one that would remain in place and be sacrificed to the construction process. The claimants accept that a Visqueen membrane was installed on the roof but it was not a sacrificial membrane and, importantly in my view, it was to be and was removed as the modular units were craned into place.

The architects prepared a joint statement and, although no evidence was called on behalf of the defendants, I regard the agreed opinions as in evidence since Mr Ferguson, who was party to the statement, gave evidence on behalf of the claimants. It is also appropriate for me to refer to the unagreed opinions which give context although Ms Williams’ opinions on such matters were not adduced in evidence. The joint statement was produced in a slightly unusual manner. It included a background section which set out the experts’ understanding of the key events and appeared to be an agreed statement of their understanding of the facts. The experts had been asked to address a series of questions and Schedule 1 to the joint statement set out their responses to each of the questions. Where they were wholly agreed they set out a single response. Where they were not wholly agreed they set out their separate response even if those separate responses demonstrated that there was, in fact, a large measure of agreement.

In Schedule 1, these experts agreed that they had seen no evidence that a sacrificial membrane was installed. In the background section, the architects agreed that photographs taken after the storm showed that Click St Andrews had protected the property with a black plastic membrane that had been loosely laid over the open joists of the crash deck and that water could be seen on the top of the membrane where it had collected between the joists. To position the modules, Click St Andrews had to “peel back” the membrane and expose the crash deck locally and then re-protect it once the module was in place. Despite the submissions of Mr Emmett, there was no evidence that a sacrificial membrane had, in fact, been installed and, so that it is clear, I find as a fact that there was no sacrificial membrane installed and only the Visqueen or black plastic membrane to which the experts referred.

In Schedule 1, they said they had not seen any evidence as to when the Visqueen membrane was purchased or installed. They then addressed two questions on which their answers were not wholly in agreement: (i) If the First Defendant did lay a waterproof membrane, was it installed correctly, and did it cover the entirety of the roof? and (ii) Did the First Defendant properly plan for and provide adequate temporary waterproof protection to the Property during the works? Neither expert expressed an opinion on the factual premise of the questions but both proceeded on the basis that Click St Andrews had laid a Visqueen EcoMembrane.

Ms Williams expressed the opinion (with which Mr Ferguson did not agree) that as an impervious plastic sheet this had the potential to be used as a temporary waterproofing membrane. However, she said that there was no standard guidance for its use in this manner. That was unsurprising since they were agreed that the manufacturer only provides guidance for using this membrane at ground level. The manufacturer’s guidance states that it should be installed on a smooth continuous surface, such as a grouted beam and block floor, or a compacted blinding layer or a smooth concrete blinding, and then covered immediately to prevent damage from following trades. Visqueen also provided a letter dated 30 September 2022 to the claimants which stated:

“Visqueen EcoMembrane DPM is suitable for use in ground floor constructions only, positioned above or below the structural floor, to protect the building against moisture from the ground. The product is not intended for use where there is a risk of hydrostatic pressure or is not covered by a protective screed or layer to prevent damage.”

From the photographs they had seen, the experts agreed that the membrane sagged between the joists; the joints were not taped; and it was not protected from foot traffic. Further, they could not tell if it covered the whole roof. They did not agree as to whether it would be subjected to hydrostatic pressure or needed to be protected from sunlight.

As to the second question, the experts further agreed that the works appeared to have been planned so that the modules would be craned into position in summer on a single day to reduce the risk from adverse weather. Ms Williams considered that, although the membrane would have to be peeled back when the modules were craned into position, the risk to the Property was mitigated by planning for this to happen in a single day and that there was thus adequate protection. She added the following “provision” to this opinion:

“The evidence is that the Visqueen damp proof membrane was adequate for the weather conditions, including light rain on 24 July, during the period from its installation until the exceptional rain event rain event of 25 July when craning was in progress, and it is likely that it had been peeled back in part to allow this to happen. …” (my emphasis).

The experts then agreed that, given the yellow weather warning on 23 July, and the possibility of using a back up date, Click St Andrews ought to have delayed the crane lift planned for 25 July.

Mr Ferguson did not agree that the protection was adequate in any event. He made the points that when the membrane was displaced any water that had gathered was likely to be displaced into the flats below and that, when installing the modules, workmen would have had to walk on the membrane which was likely to displace it. The need to displace the membrane to fit the modules meant that, in the event of even light rain, water ingress would have been inevitable during installation. In his opinion, a sacrificial waterproofing layer below the transfer structure, that is the steel sub-frame, would have avoided any displacement.

Mr Ferguson was cross-examined on the opinions expressed in the joint statement. He was asked if it was possible to put the tin hat roof back on after the weather warnings. Mr Ferguson’s response was that it would have been possible after the first yellow weather warning (but not after the crane lift had begun) but he emphasised that it should not have been necessary as there needed to be a secondary measure to protect the roof whether there was rain or not. He agreed that the rain on 25 July was exceptional but he did not agree that the membrane would have been adequate protection if there had not been exceptional rainfall because any rainwater that had collected on the membrane had nowhere to go.

Mr Ferguson was also asked about the use of a so-called water vacuum cleaner to meet this point about water collecting on the membrane – he was aware of them, he had not seen them in operation, there was no mention of the use of one in any risk assessment for these works and he had not seen any evidence that one was used. I observe that this was the first mention of such a water vacuum cleaner and that Mr Ferguson was right to say that there was no evidence of one being used. If this was being put forward as a means of rendering the membrane adequate protection, it was irrelevant because it was not what happened which was in the control of Click St Andrews.