Grenfell cladding manufacturer calls failure to release devastating fire tests on material used on tower a ‘non-issue’ 

But today Stephen Hockman KC, appearing for Arconic, claimed that the firm was the victim of “an agenda” to condemn it “even before the case has been fully heard”. 

He said that at the “material time” the sale of ACM in the UK was “entirely lawful”, demonstrated by almost 500 tall buildings around the country clad in the material. 

He described the UK government’s attempt to claim in the immediate aftermath of the fire that combustible cladding was “banned” by its guidance as “a political lie”. 

The cladding was sold with a certificate from the British Board of Agrement (BBA) – a respected third-party certification firm – which said it “may be regarded” as having a Class 0 surface and a European fire rating of ‘B’.

Either standard would have been acceptable under official government guidance for the cladding to be used on a high-rise building.  

But while Arconic had obtained the European ‘B’ rating when the panel was fixed to a wall with rivets, it had a best rating of ‘E’ when it was bent into cassettes, with testing showing that it burned far faster and released much more heat and smoke in this form. It was ultimately used in cassette form on Grenfell Tower.  

However, Mr Hockman said that UK clients would have been content to use the product even if they knew it did not have a ‘B’ rating, so long as it obtained the alternative grade of Class 0. 

“If this is right, it would follow that the fundamental line of attack against AAP [Arconic Architectural Products] said to arise from the non-disclosure of the cassette testing in 2005 can be seen as a non-issue,” he said. 

The BBA certificate contained diagrams showing both cassette and riveted fixings with no reference to the drastic reduction in fire performance relating to the cassette form.

But Mr Hockman rejected any suggestion that the certificate was “misleading” in this regard, saying that Arconic sold its ACM as a flat panel, which was then fabricated into either cassette or riveted form by others. 

He said that if the certificate was “read as a whole”, it became clear that further testing was required to guarantee its safety in any particular system. 

“Therefore the primary responsibility for any alleged misuse of the product must lie with those actually responsible for the design and construction of the architectural project in which the product is used,” he said.

Mr Hockman was followed by Geriant Webb KC (pictured above), representing insulation manufacturer Kingspan, which produced a small amount of the combustible insulation used behind the ACM cladding. 

Mr Webb referred to testing by inquiry expert Professor Luke Bisby which appeared to show that the ACM was the cause of the rapid fire spread, and that the combustibility of the insulation was not a relevant factor. 

“The expert evidence demonstrated in our submission that the presence of the [polyethylene-cored] ACM effectively eclipsed everything else,” he said.

“All of the expert evidence is consistent: the type of insulation made no material difference to the speed and spread of the fire.” 

Lawyers for bereaved and survivors yesterday urged the inquiry to “sup with a very long spoon” when considering these arguments, pointing out that Professor Bisby’s tests were relatively small scale and previously untested, and that their experts had not had the opportunity to challenge his conclusions. 

Mr Webb also stressed that Kingspan has passed 15 large-scale fire tests since the blaze, which he said demonstrated that the product can be used as part of a safe system. 

He added that the firm has “accepted and apologised for the fact that there were shortcomings in relation to the testing and certification” of its K15 product, the material ultimately used on Grenfell Tower.

He added: “Mistakes were made which should not have been made. However, none of those shortcomings were causative of the fire or the nature or speed of the spread of the fire in any way.”

The inquiry has previously seen messages between Kingspan staff members saying “all we do is lie in here” in reference to its fire safety claims about its insulation. 

Another staff member said a consultant raising concerns about safety could “go fuck themselves” or Kingspan would “sue the arse off them”. 

Mr Webb said the inquiry’s disclosure process had “unearthed a handful of emails and chats involving a small number of former employees which have revealed conduct which was unacceptable and totally inappropriate”. 

He said the firm had apologised for this behaviour and added: “These isolated communications, however, are the exception… fire safety is at the very heart of Kingspan Insulation’s business and it could not be taken more seriously.”

He also addressed a test in December 2007, when a cladding system containing Kingspan’s insulation was involved in a serious failure. 

An internal document said the test was a “raging inferno” and the Kingspan insulation “burned very ferociously” and was “very different in a fire situation to the previous technology” – a reference to an earlier version of its insulation that had been part of a system that passed a test in 2005. 

Today Mr Webb said the test failure was not a result of the combustibility of Kingspan’s insulation, noting that the system also failed when tested with non-combustible insulation in January 2008. He said the failure was a result of the system, not Kingspan’s insulation. 

“It was put to several witnesses that this 2007 test somehow demonstrated that new technology K15 failed, even that it failed spectacularly when tested,” he said. “Such assertions are plainly and obviously wrong.”