Firm worked hard to get unsuitable flammable insulation approved for high-rise use, backed with ‘untrue and misleading’ certification


Former staff of insulation company Celotex continued giving evidence to the Grenfell Tower Inquiry this week, providing a detailed picture of the extreme lengths to which the firm went to get a combustible product portrayed as safe for use on high-rise buildings.

On Monday ex-product manager Jonathan Roper said the firm had exploited “ignorance” about fire-testing regimes within the construction industry to sell its flammable RS5000 polyisocyanurate (PIR) product as suitable for use on structures above 18m in height.

Celotex Jonathan Roper 2

Jonathan Roper

Roper told the inquiry into 2017’s fire disaster – which claimed 72 lives – that Celotex had behaved in a “completely unethical” way to ensure it had a product that could be pushed as suitable for use as part of cladding systems on tall buildings.

He said that when the firm’s FR5000 PIR insulation had failed a Building Research Establishment fire test in April 2014, the product had been rebranded as RS5000. The product went on to pass a BS8414 test the following month, but the result had been rigged through the inclusion of a non-combustible magnesium oxide board to improve the chances that the combination of materials would fare better.

Neither the presence of the magnesium oxide board nor the fact that gaps within the test structure were reduced to improve its fire performance in comparison with the official measurements were ever disclosed to customers.

Celotex FR5000 was originally specified for Grenell Tower in 2012 and made it onto the NBS specification for Kensington and Chelsea Tenant Management Organisation’s procurement exercise to find a main contractor for the block’s refurbishment, which concluded in 2014. However, “new” product RS5000 was the main insulation used on the exterior of the building for its ill-fated upgrade.

Inquiry lead counsel Richard Millett QC asked Roper whether Celotex’s behaviour in seeking to manipulate the BRE test had struck him as dishonest. “Yes, it did,” he replied.

Asked by Millett why he had gone along with the deception, Roper replied: “I went along with a lot of actions at Celotex that, looking back on reflection, were completely unethical and one that I probably potentially didn’t consider the impact of at the time.”

He added: “I was 22-23, first job, I thought this was standard practice although it did sit very uncomfortably with me.”

Roper said Celotex had keen to exploit market-ignorance and had its eyes on revenue worth £10m to rival insulation firm Kingspan.

On Tuesday Roper told the inquiry Celotex had seized on inspection body Local Authority Building Control’s seeming confusion about the meaning of the “class 0” fire rating to secure a certificate declaring RS5000 safe to use on buildings above 18m in height.

As was common in the construction industry at the time, the class 0 rating was wrongly believed to mean the product was of limited combustibility. However class 0 in fact only refers to a product’s ability to adequately resist the surface spread of fire.

Some of the wording for the LABC certificate granted to RS5000 was essentially Celotex’s own marketing material for the product which had been e-mailed over to the organisation. The certificate was later sent to Grenfell refurbishment facades subcontractor Harley.

Roper admitted that the certificate was “untrue and misleading” and agreed with Millett’s suggestion that Celotex had “intended that to be the case as a way of avoiding being challenged by building control officers down the track”.

Also on Tuesday, Roper told the inquiry how he had helped Celotex manipulate technical drawings representing the cladding system in which RS5000 passed the BRE test to make it appear that the cavity between the insulation and external panels had been larger than had been the case.

He admitted he had asked for the test rig to be constructed with very small ventilation gaps because it was Celotex’s intention to “overengineer the rig so that it passed”.

On Wednesday the inquiry looked at the marketing material that Celotex put out for RS5000, which expert architecture witness Paul Hyett, a former RIBA president, said earlier in the month “sets out to mislead”.

Former head of marketing Paul Evans accepted Millett’s suggestion that documents repeatedly stating RS5000 was “acceptable for use in buildings above 18 metres in height” were “thoroughly misleading”.

Celotex Paul Evans 1

Paul Evans

Millett asked how the material could have been released to the market on his watch, Evans replied: “Only by relying on other people to give information, and decisions have been made and things have been moved on which has led to us promoting the system this way.”

The session heard that both contractor Durkan – which was shortlisted for the Grenfell refurbishment but beaten on price by eventual main contractor Rydon – and developer Ardmore had raised concerns that the National House Building Council had about RS5000 with Celotex.

The organisation, which conducts independent building inspections and provides warranties for new homes said it would not accept the certification provided by Celotex.

In a January 2015 email chain that Evans was copied in to, Nigel Shields of Durkan reported to Celotex that NHBC would not accept the fire-test certification that the firm had provided for RS5000 because it “does not represent [a] true test of the product in all of its applications”.

The marketing claims made by Celotex for RS5000’s suitability for use on high-rise buildings only covered systems that were the same as the one that passed BRE’s BS8414 test. Even then – as the inquiry heard – the actual configuration of materials used in the test was not accurately detailed to customers.

In March 2015, Celotex received an official complaint from Ardmore, which had been asked to remove RS5000 from a 121-home high-rise project after the NHBC said the insulation was an unacceptable product for the structure.

Ardmore’s technical director Richard Hunt said the firm was “amazed” that an international supplier and manufacturer of Celotex’s reputation would “send products to market that are not suitable for their intended use”.

In July 2016, NHBC published a guide stating that both RS5000 and rival product Kingspan Kooltherm K15 were acceptable for use with cladding systems provided that the design specification met minimum requirements.

On Thursday, the inquiry questioned former Celotex technical services team leader Jamie Hayes about his involvement with the successful May 2014 BS8414 test that RS5000 passed.

He said he had been aware that the Celotex team had been considering the use of a thicker 12mm version of the Marley Eternit cement rainscreen panels compared with the 8mm panels used on the earlier failed test to improve the test systems resistance to fire.

Hayes said it had been his idea to introduce a non-combustible magnesium-oxide board to the test system as a way to improve the cladding panels’ fire resistance.

But he told the inquiry that it had not been his decision to conceal details of the actual cladding system that had passed the BS8414 test and produce a compliance guide for RS5000 that did not properly reflect the rig that had been used.

“I didn’t have any control over how Celotex had chosen to go down that route, although I absolutely accept that I knew about it and didn’t do what was right in raising it,” he said.

“What was under my control was […] was to at least diligently ensure that people did receive the compliance guide.”

However Hayes accepted that when customers were directed to the compliance guide for RS5000 he was “referring people to a document which was fundamentally incorrect”.

The inquiry heard that both Ardmore and Harley had struggled to get full details of the set-up Celotex had used to obtain the BS8414 test pass for RS5000 because the manufacturer had refused designers access to the actual BRE test report.

Millett asked Hayes how he thought designers would be able to comply with guidance in Approved Document B of the Building Regulations without it.

Forrmer Celotex technical services team leader Jamie Hayes

Jamie Hayes

“I don’t think they would be able to,” he replied. “I did realise that it was ridiculous, really, that they would not have that access to that document.”

Hayes said there was a “deliberate misleading” on the part of Celotex in terms of the tested system and the company “did not want to encourage people to ask questions about the specific details of the test”.

He earlier confirmed to the inquiry he had joined Celotex in 2004 as a temporary administrative worker before moving to the company’s technical services team three years later. He said the team sat “squarely” in the marketing department and that he had no technical training. He said his technical knowledge was “entirely picked up on the job”.

The inquiry continues next week.