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Grenfell Tower Inquiry recap: module two – the cladding products

Insight01.11.227.00 AM by Peter Apps

As the Grenfell Tower Inquiry prepares to return for closing statements, Peter Apps recaps some of the evidence relating to the testing, sale and certification of materials used in the building’s cladding system

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As the Grenfell Tower Inquiry prepares to return for closing statements, here is a recap of evidence relating to the materials used in the cladding system #UKhousing

Evidence covering the refurbishment of Grenfell Tower ran from October 2020 to March 2021, much of it conducted over Zoom because of the coronavirus lockdown.

As the various participants prepare to return to give overarching closing statements, here is a recap of the evidence.

Arconic

Its role: Arconic manufactured and sold the Reynobond PE 55 cladding panels used on Grenfell Tower.

What we learned: In 2004, Arconic’s French arm ran fire tests on its products to assess their performance against new European standards. The results were startling. When its aluminium composite material (ACM) was bent into a ‘cassette’ shape (so it could be hung on rails instead of being riveted to a building), its fire performance deteriorated sharply.

The results showed it burned 10 times as quickly and released seven times as much heat and three times as much smoke when shaped in this way, making it effectively unclassifiable under the new standards.

But Arconic neither commissioned further testing nor removed the product from the market. Instead, the test was internally branded a “rogue result” and the product remained on the market.

Arconic went on to obtain a certificate from the British Board of Agrement (BBA), a respected third-party certifying body, which suggested the ACM had a Class 0 fire performance and Euroclass B fire rating.

Either was acceptable as the minimum standard for high-rise buildings, but only the riveted panel had obtained Euroclass B. Arconic provided a test on a fire-retardant version of the panel to support its claim that it was Class 0.

The certificate, however, appeared to apply to the product in all its forms. The BBA was not told about Test 5B.

Inside Arconic, warnings about the dangers of ACM mounted in the years before Grenfell, as other fires occurred globally. In one 2007 document, a senior member of the company speculated about a fire killing “60/70” people in a tower clad with its material.

When a salesperson based in Spain queried the fire rating of the product, Claude Wehrle, a technical manager, replied, explaining that the material could not achieve Class B in cassette form. But he added: “This shortfall in relation to this standard is something we have to keep VERY CONFIDENTIAL!!!!”

Further testing in 2011 duplicated the results from 2004, showing the stark difference between the riveted and cassette panel.

While the product remained on the market, Mr Wehrle did eventually email salespeople in February 2014, advising that the product had only achieved Euroclass E – based on the cassette testing – and saying the B-classification “can no more be used from now”.

This email went to its UK salesperson, Debbie French, who was finalising a sale of the panels for use on Grenfell Tower. Despite receiving this email, she sent the BBA certificate which contained the B-grading to the team refurbishing the tower.

She said she believed Class 0 was all that was relevant in the UK, and she did not think the Euroclass B grading mattered.

Challenged on whether she had decided to keep the new information to herself, knowing it could hurt sales, she said: “Absolutely not.”

In its statements, Arconic emphasised that its cladding could be used safely, that the BBA certificate only applied to its product in sheet form and that it had no involvement in the design process for Grenfell Tower.

One key exchange: “Do you accept that if the Grenfell Tower fire had never happened, no one would have known about the failed Test 5B?” asked Richard Millett (QC at the time, now KC), lead counsel to the inquiry.

“Yes,” replied Claude Schmidt, the company president, pictured above, speaking through a translator.

“Do you accept that Test 5B was Arconic’s deadly secret?” asked Mr Millett.

Mr Schmidt said he did not.

“The product that was sold was not dangerous in itself, it did have some risks which were dealt with differently in different countries… there are many things we use every day that give rise to some risk,” he said.

Key week: Week 24. Read our summary here.

Celotex

Its role: Celotex manufactured and sold RS5000, the insulation material used behind the cladding panels on Grenfell Tower.

What we learned: Celotex, a medium-sized British insulation manufacturer, was purchased by global firm Saint-Gobain in 2012. Seeking to boost its profits, the parent company instructed Celotex to find new product lines.

One area where Celotex lagged behind its competitors was high-rise buildings. Statutory guidance required insulation to be of limited combustibility, which meant mineral and glass wool products, not the plastic foam Celotex produced.

But Celotex’s competitor Kingspan was selling its K15 product for use on high-rise buildings and a young recruit, Jonathan Roper, pictured above, aged just 22, was asked to find out how.

He discovered that Kingspan had passed a large-scale test which should have permitted the use of K15 only as part of the system tested, but Kingspan was marketing it more widely.

“An architect will be told that K15 is applicable for above 18m… and that suffices from their perspective,” he wrote in an email in November 2013.

Mr Roper suggested Celotex could try to repeat Kingspan’s method – passing their own test and then marketing the product for use on high rises more widely – but he sounded a note of caution.

“Do we take the view that our product realistically shouldn’t be used behind most cladding panels because in the event of a fire it would burn?” he wrote.

The company elected to go ahead with a test, the first of which was carried out at a facility owned by the Building Research Establishment (BRE) in February 2014.

This was a failure. The company had tested its insulation behind a non-combustible cladding board, but it cracked and let flames through to the combustible insulation.

It tried again. This time, it reinforced the external cladding with additional fire-resisting boards to help prevent it cracking. The test was a success.

But the fire-resisting boards were not mentioned in the BRE’s test report. Nor were they mentioned in the marketing literature Celotex produced to describe the test, which said the product was “suitable for use on buildings above 18m”.

Asked why he went along with this, one witness, Celotex employee Jamie Hayes, said: “I didn’t know who I should speak to or could speak to. I lacked the life experience to find the right way forward and it was a failure of courage, and a failure of character and a failure of moral fibre on my part not to do so.”

The firm then secured a certificate from Local Authority Building Control (LABC), a membership body for town hall building control officers. This said the product “can be termed a material of limited combustibility” and was “suitable for use within the wall construction even at heights above 18m”.

This was simply not true, but Celotex did not seek a correction. In fact, they specifically targeted high-rise jobs – including Grenfell Tower – which they intended to use as a “case study” for their insulation.

Celotex has emphasised that all staff involved in this testing process have left the company and that a repeat of the March 2014 test without the additional boards was passed after the fire.

One key exchange: “Is it right that… by failing to ensure that [the LABC certificate] reflected the fact that [a large-scale test] is only for the system tested, Celotex ran the risk of misleading customers?” asked Mr Millett.

“Yes,” replied Mr Roper.

“And misleading building control officers?” asked Mr Millett.

“Yes,” replied Mr Roper.

“And that was intentional, deliberate and dishonest?” asked Mr Millett.

“I believe so, yes,” replied Mr Roper.

Key week: Week 19. Read our summary here.

Kingspan

Its role: Kingspan manufactured K15, a small quantity of which was used on Grenfell without the company’s knowledge.

What we learned: After regulations changed in the early 2000s to allow the use of combustible insulation products within a system that had passed a large-scale test, Kingspan was the first manufacturer to secure a pass in one of these tests.

However, it did so using a system which placed its insulation behind cement fibre cladding, a non-combustible material and not a common choice for real-world buildings.

It hoped the BRE, which carried out the test, would issue a certificate that allowed the result to be extrapolated to other buildings. But when this was not forthcoming, it nonetheless marketed K15 for use on high-rise buildings for a wide variety of cladding systems.

It emerged at the inquiry that, after the 2005 test, Kingspan altered the way it made its insulation product. A new test on a different system featuring the new product burned fiercely: internal company documents described a “raging inferno” and said the insulation “burnt very ferociously”. But the 2005 test was still used to support the claim that K15 could be used on high rises.

Like Arconic, Kingspan secured a certificate from the BBA. Issued in 2008, this certificate said the product “will not contribute to the development stages of a fire or present a smoke or toxic hazard”. A later version of the certificate said the material could be used “in accordance with” paragraph 12.7 of Approved Document B, the section of the statutory guidance that relates to insulation on high-rise buildings.

Under questioning, BBA witnesses would accept that this certificate was “misleading” and produced by reliance on tests on other Kingspan products.

The firm also secured an LABC certificate, which said the material “can be considered a material of limited combustibility”. This was plainly untrue, but was celebrated by Kingspan staff as “fanbloodytastic” in internal emails.

Asked how it was secured, one Kingspan staff member said in an email: “We can be very convincing when we need to be, we threw every bit of fire test data we could at him [the surveyor who produced the certificate], we probably blocked his server… We didn’t even have to get any real ale down him!”

Repeatedly challenged over the suitability of their product by the National House Building Council (NHBC), the county’s largest private building control inspector, Kingspan sought further testing in 2014. It did pass one test, but it has emerged that this was carried out using a trial product that never made it to market.

When the NHBC threatened to stop accepting K15 on high-rise buildings, Kingspan threatened it with legal action for defamation.

The inquiry also heard about Kingspan’s post-fire lobbying, and its attempts to convince a parliamentary select committee that a ban on combustible insulation was undesirable. Under questioning, its witnesses denied the firm had done “its best to ensure that science was secretly perverted for financial gain”.

Kingspan has said its insulation was “misused” on Grenfell Tower, and has pointed to expert evidence which shows the fire would still have spread rapidly with non-combustible insulation because of the fiercely combustible nature of the cladding panels.

It says new testing supports previous claims about its product and says it has “sincerely apologised for these actions by a small group of employees at our Kingspan Insulation UK business”, which it claims “in no way reflects Kingspan’s culture or values”.

One key exchange: Towards the end of the evidence given by witness Phil Heath (a Kingspan employee, pictured above), Kate Grange QC (now KC) asked him why there was so little concern for life safety in the documents they had reviewed.

“It’s there in black and white, isn’t it?” she said. “We see a complete absence of any consideration of life safety; that’s right, isn’t it?”

“I don’t believe that was the mindset of Kingspan at that time, but on reflection I can see why you think that, yes,” replied Mr Heath.

Key week: Week 21. Read our summary here.

Building Research Establishment (BRE)

Its role: The BRE ran several large-scale tests on systems containing K15 and RS5000.

What we learned: In Module Two, the BRE’s role in running tests on the Celotex and Kingspan insulation products was placed under the microscope.

A crucial question was whether their scientist, Phil Clark, knew that Celotex was using fire-resisting boards to strengthen the cladding panels in its test in March 2014. The evidence of Celotex witnesses was that he did, but this is something he flatly denied.

The boards were visible in several photos of the rig, but a delivery slip recording their arrival at the test facility was mysteriously missing.

Several normal steps were also not taken in this test, including photographing the components before the test rig was assembled. Mr Clark said he thought he was off work on the day in question.

Helmet-camera footage of the test then showed him saying “see how that flame seems to have ceased now that the board is there” as he observed the test play out.

He said that the word “boards” was merely a reference to the external cladding panels and his use of the word “now” was no more than “misuse of a word” in “general conversation”.

It emerged during his evidence that he had had three days of unsupervised access to the BRE’s files to prepare his witness statement, something he initially claimed had not happened, before being corrected by the BRE’s lawyers.

Months later, a more-senior member of the BRE, Debbie Smith, was asked what systems had been put in place to prevent him removing or destroying evidence as he did this. She said she could not comment.

A further issue surrounded a Kingspan test in 2014. This test failed when flames breached the top of the test rig and should, under the rules, have been stopped.

But Mr Clark allowed it to run on. Helmet-camera footage showed him discussing his notes with Kingspan employees.

As he noted that flames passed the top of the rig, a Kingspan employee said: “Can’t you just delete the whole sentence?”

Mr Clark replied: “I will put…” before trailing off.

He denied that this showed “collaboration” with Kingspan. After the test concluded, the firm challenged its categorisation as a failure – which the BRE resisted.

The BRE did, however, provide Kingspan with a report which did not spell out that the test had failed. It emerged that this report has been used to support the use of K15 on high-rise buildings, despite the failed test.

Mr Clark went on to work for Kingspan after the Grenfell Tower fire, to help establish their own testing facility, before being made redundant and joining the BBA.

One key exchange: “This is quite an incredible list of omissions and missed instances, isn’t it?” Mr Millett asked, running through the irregularities surrounding the March 2014 Celotex test.

“Yes, I probably agree with you, yes,” Mr Clark replied.

“I mean, Mr Clark, isn’t the reality that you knew very well that there was a 6mm magnesium-oxide layer behind it? You were in charge of this test, the photographs showed it was there, the deputy knew it was there… and it was covered over by a perfectly obvious ruby-coloured band in two places of a material of a different thickness. Surely you must have realised what was behind it?” Mr Millett said.

“No, I would have reported it. And had I known it, I would have stopped the test,” Mr Clark stated.

Key week: Week 25. Read our report here.

Grenfell Tower Inquiry phase two: weekly diaries

Module one: the refurbishment

Week one: A vivid picture of a broken industry

After a week of damning revelations at the opening of phase two of the Grenfell Tower Inquiry, Peter Apps recaps the key points