“What was the point of having a detailed standard operating procedure such as this… which you didn’t use?” asked inquiry counsel Richard Millett.
Mr Clark answered that the sheets were “more of an aide memoir” as to what steps to go through.
The BRE also didn’t receive drawings of the planned test rig, with Mr Clark saying this wasn’t unusual and happened because the test in May 2014 was similar to a previous one which Celotex had failed, only with a thicker cladding board used.
“Wasn’t it essential for the BRE to know the composition of the system being tested?” asked inquiry chair Sir Martin Moore-Bick.
“I understand your question and the answer is from checking the delivery notes and checking and measuring on site. It wasn’t common practice to insist on having them [drawings] before the test, maybe it should have been, but it wasn’t,” he said.
He said that he was away on a first aid course when the test was constructed and could not explain why his deputy did not notice the additional fire boards being installed, other than to say the rig was only checked at certain specific times by the BRE.
The boards were covered over with panels of a different thickness – which were different in colour to the rest of the rig – and were visible behind them in photographs of the build up taken by the BRE.
Mr Clark said that these photographs were taken from height and that the boards – potentially 8m above the ground – would not have been visible from where he was standing at ground level.
“This is quite an incredible list of omissions and missed instances isn’t it?” asked Mr Millett.
“Yes, I probably agree with you,” said Mr Clark.
“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 as it must have taken time to put up and it was covered over by a perfectly obvious ruby coloured band in two different places by a material of different thicknesses,” said Mr Millett. “Surely you should have known what was behind it?”
“No I would have reported it and had I known about it I would have stopped the test,” said Mr Clark.
Jamie Hayes, a witness for Celotex, previously told the inquiry he had “no doubt at all” that Mr Clark knew about the boards.
Earlier the inquiry was shown video footage of Mr Clark telling Celotex employees that their first test, carried out in February 2014, had likely failed due to the cladding distorting and pulling away, rendering the cavity barriers ineffective. He was recorded saying he had “seen worse failures”.
But he denied under questioning that this constituted offering advice to Celotex and accused a Celotex witness, Jonathan Roper, who testified that he had advised thickening the panels to give a better chance of passing on a second attempt of lying.
At the start of his evidence he was asked whether the BRE influenced the government into adopting the testing methodology as a route to getting cladding system to comply with guidance for commercial reasons.
The BRE proposed the new testing methodology in 1999, two years after it was privatised in 1997 and was the only organisation with the facility to carry the tests out when it was first introduced into guidance.
Mr Clark agreed that the BRE had influenced the process of this system being adopted but said this was because it was “the right thing to do” as opposed to a commercial motivation.
He accepted that Brian Martin – now a top civil servant at the Ministry for Housing, Communities and Local Government – had been seconded from his role at the BRE to work part time within government on the new testing methodology.
“Would it be fair from your knowledge to desribe BS8414… as a joint project between government and BRE with Brian Martin on both sides?” he said. Mr Clark replied that this was a “a fair assumption”.
Earlier, the inquiry heard that Mr Clark left his job at the BRE in December 2017 after the Grenfell Tower fire, having been made a lucrative offer by competitor Exova Warringtonfire.
A year later, he was employed by insulation manufacturer Kingspan, to take over a new in-house fire testing programme they had begun to develop.
But he was made redundant with “10 minutes” notice this June, shortly before details of Kingspan’s testing at the BRE was made public by the inquiry. Mr Clark said he believed his departure was linked.
“It’s not long after that happened that the information came out about what Kingspan were doing with regard to the falsification of tests, but I have got no substantive evidence, it’s just a feeling I had at the time,” he said.
The inquiry has previously heard Kingspan hid devastating test failures from the market and did not declare a change to its product following a successful test in 2005 which appears to have reduced its fire performance.
The inquiry continues with further evidence from Mr Clark tomorrow.