Manufacturers knowingly misled the market over combustible construction materials, Grenfell Inquiry concludes

Major construction product manufacturers intentionally manipulated and misrepresented fire safety tests in order to mislead the market over combustible materials, the Grenfell Inquiry has concluded.

According to the Phase 2 report, published this morning, the “systematic dishonesty” of those who made and sold rainscreen cladding panels and insulation products was “one very significant reason” that Grenfell ended up with combustible cladding.

Arconic, Celotex and Kingspan were all slammed by the inquiry for their actions, while certification and test bodies such as the British Board of Agrement (BBA), Local Authority Building Control (LABC) and the Building Research Establishment (BRE) were also criticised for their roles in allowing dangerous products on the market.

In the case of Arconic, the inquiry found that from early 2005, the firm possessed test data showing that its ACM cladding, Reynobond 55 PE rainscreen panel product, reacted to fire in a very dangerous way when used in cassette form, as it was on the external wall of Grenfell Tower.

Nonetheless, it persisted in telling the market that the panels had been classed B-s2, d0 under the European classification system, even though this was only true for the product used in its riveted form.

It continued to do this despite mounting evidence of the product’s potential danger in the years that followed. Despite knowledge gained from cladding fires in Dubai in 2012 and 2013, Arconic did not consider withdrawing the product in favour of its fire-resistant version. 

After further testing in 2013, Arconic decided that Reynobond 55 PE would be certified as Class E only, whether used in riveted or cassette form. But it did not tell its UK customers or the BBA this, which the inquiry held to have been “a deliberate strategy”.

When a French testing house classified the panels in riveted form as Class C and in cassette form as Class E in December 2014, the manufacturer once again failed to inform the BBA.

Meanwhile, Celotex was found to have “embarked on a dishonest scheme to mislead its customers and the wider market” in order to break into the market for high-rise insulation with its RS5000 product, a combustible polyisocyanurate foam insulation.

In May 2014 Celotex tested in accordance with BS 8414, a system incorporating RS5000 that contained two sets of fire-resistant magnesium oxide boards placed in critical positions to ensure that it passed. It then obtained from BRE a test report that omitted any reference to magnesium oxide boards, thereby rendering it “materially incomplete and misleading”.

The inquiry said that in this instance, the BRE was “complicit” in Celotex’s deception.

It found that the BRE’s systems were “not robust enough to ensure complete independence and the necessary degree of technical rigour at all times”, as a result of which it “sacrificed rigorous application of principle to its commercial interests”.

Celotex marketed RS5000 as having successfully tested to BS 8414 and therefore acceptable for use in buildings above 18m. 

However, it only mentioned in the small print of its marketing literature that this was a system test and did not involve the testing or classification of individual products.

Kingspan was also found to have spread falsehoods in marketing of its K15 product.

While K15 was not used on Grenfell in a particularly large quantity compared with the other two products, the inquiry found that the way in which it was tested and marketed “created conditions that encouraged unethical practices in the supply of insulation for use on high-rise buildings”.

The Irish firm claimed that its K15 product had been part of a system successfully tested under BS 8414 and could therefore be used in the external wall of any building over 18m in height “regardless of its design or other components”.

“This was a false claim as it well knew”, the report said, because BS 8414 is a method for testing complete wall systems and its results apply only to the particular system tested.

“As Kingspan knew, K15 could not honestly be sold as suitable for use in the external walls of buildings over 18m in height generally, but that is what it had succeeded in doing for many years,” it said.

Furthermore, the BS 8414-1 test that K15 had passed was based on a system whose components were “not representative of a typical external wall” and it continued to rely on that test “without disclosing that it had changed the composition of the product in 2006”.

Systems including the altered product failed tests in 2007 and 2008, tests which the report described as “disastrous”, but Kingspan did not withdraw the product.

It “concealed” from the BBA the fact that the product it was selling, to which a certificate was issued in 2008, was different from the one that was tested in 2005. In 2009, Kingspan also succeeded in getting a certificate from LABC which contained “false statements” about K15 and supported its use generally on buildings over 18m.

“Kingspan cynically exploited the industry’s lack of detailed knowledge about BS 8414 and BR 135 and relied on the fact that an unsuspecting market was very likely to rely on its own claims about the product,” the report said.

The inquiry said that the “dishonest strategies” of Arconic and Kingspan succeeded “in large measure due to the incompetence of the BBA”, including its failure to adhere robustly to the system of checks it had put in place and an “ingrained willingness” to accommodate customers rather than insistent on high standards.

“Its scrutiny of the fire performance of K15 and Reynobond 55 PE was seriously deficient and the certificates it produced for those products were misleading,” the report found.

The body “failed to manage the conflict” between commercial impulses and the need for a high degree of rigour and independence, accepting wording in certificates that was proposed by manufacturers and which was wrong and misleading.

The LABC was also found to have a “share of the blame” for the acceptance of Celotex RS5000 and Kingspan K15 by the market.

According to the inquiry, there was a “complete failure” over a number of years to take basic steps to ensure that certificates issued in respect of them were technically accurate and it fond hat the LABC was “vulnerable to manipulation because its processes were not implemented rigorously enough.”

Initial assessments and second stage reviews were often carried out by professionals who were not always competent to do so. 

LABC’s certificates relating to the two products “contained misleading statements about their fire performance and about the suitability of both products for use in the external walls of buildings over 18 metres in height”.

Meanwhile, the NHBC was found to have failed to ensure that its building control function was “essentially regulatory and free of commercial pressures” and was “unwilling to upset its own customers” by revealing the scale of the use of combustible insulation in the external walls of high-rises.

“We have concluded that the conflict between the regulatory function of building control and the pressures of commercial interests prevents a system of that kind from effectively serving the public interest,” the inquiry conclude