Grenfell insulation was ‘horsemeat masquerading as beef’, says designer

Grenfell Tower’s Celotex RS5000 insulation “more likely than not” contributed to the spread of fire up the building on 14 June 2017, inquiry chair Sir Martin Moore-Bick concluded in his phase one report.

It remained described as suitable for high rises on websites including that of Celotex’s owner Saint Gobain a year after the fire.

At the time of the refurbishment, official guidance required insulation to be of ‘limited combustibility’ or part of a system that had passed a large-scale test to be permitted on high rises.

It had passed a large-scale test, but in combination with non-combustible cement fibre cladding – meaning it was allowed only if used with similarly fire-proof cladding.

In addition, this test pass was withdrawn after an expert report previously submitted to the inquiry claimed that fire-resisting boards were placed between temperature monitors in the now-withdrawn safety test carried out on the RS5000 product.

Celotex RS5000 was also advertised as having a Class 0 rating – irrelevant for its compliance but often misunderstood as permitting it. But in September 2017, post-Grenfell testing saw it achieve the lower rating of Class 1.

Monday’s hearing also saw Mr Crawford admit that he had never heard of other major tower block fires involving external fire spread – including at Lakanal House, Garnock Court, Knowsley Heights and in Dubai.

He said he had no memory of seeing a British Board of Agrément certificate for the aluminium composite material (ACM) cladding product used on Grenfell before the fire.

Despite writing in a March 2015 email that “metal cladding always burns and falls off”, Mr Crawford told the inquiry he did not believe that would mean it does not adequately resist the spread of fire across the external wall as required by building regulations.

Asked by Sir Martin if he had any sense of the difference between ACM with a polyethylene core and solid aluminium cladding regarding fire safety, Mr Crawford replied: “I just viewed it as a laminated aluminium panel, I didn’t have any perception that it was, well, the monster that it’s become.”

Mr Crawford also faced a series of questions about why he believed that fire safety consultants Exova Warringtonfire considered that the cladding proposals for Grenfell Tower complied with building regulations.

As revealed last year by Inside Housing, an October 2013 report by Exova said that outline plans would have “no adverse effect on the building in relation to external fire spread”, but added that this view was to be “confirmed by an analysis in a future version of this report” – which it was never commissioned to do.

“My understanding from discussions with Bruce [Sounes, the previous architect who had worked on the job] is that Exova were fully aware of how the scheme had developed, including the external wall build-up,” he said.

That was despite Terry Ashton of Exova stating in a 2014 email that he had “never seen details of what you’re doing to the external walls”.

In 2012, Colin Chiles, an executive at contractor Leadbitter, told Studio E that he regarded Exova’s approach as “casual” and said it had not addressed fire safety concerns raised by the Grenfell Action Group of residents.

Leadbitter later dropped out of the project over budget concerns and was replaced by Rydon.

The inquiry continues.