Installed barriers had not been tested prior to use on tower鈥檚 refurbishment

The cavity barriers used on the refurbishment of Grenfell Tower were only formally approved as safe by the supplier nine days after the disastrous 2017 fire, the inquiry has heard.

Cavity barrier supplier Siderise had sold the barriers for use on Grenfell Tower for gaps ranging between 326mm and 425mm 鈥 despite the product only being tested to a maximum cavity of 300mm.

Mort Siderise 1

Christopher Mort giving evidence to Monday鈥檚 hearing

But Monday鈥檚 hearing was told how, in the immediate aftermath of the fire which claimed 72 lives, the firm had ordered a report which extended the application of the barriers to gaps of up to 425mm.

Asked what had prompted Siderise to order the report at this stage, the firm鈥檚 technical officer for fire Christopher Mort said that 鈥渋t was just requested from the business鈥.

Counsel to the inquiry Kate Grange QC asked: 鈥淲as that in response to the Grenfell Tower fire that it was requested?鈥 Mort replied that he 鈥渃ouldn鈥檛 say鈥, adding that he was never told.

Asked what the extension field of application reports (EXAPs) were based on, Mort said that the report had 鈥渇ormalised鈥 historic data already in the possession of Siderise. No record of this data has been supplied to the inquiry.

Grange asked: 鈥 Can you explain how Siderise were able to supply cavity barriers for voids between 326 and 425 millimetres at Grenfell Tower when it appears that no testing to those void widths or any extended application assessments had been undertaken at that time?

Mort replied that the EXAPs had been 鈥渦ndertaken but not in that formal form鈥.

Asked if the data which the EXAPs was based on existed, Mort answered: 鈥淲ithout looking into鈥 I wouldn鈥檛 say there was actual formal documentation. It鈥檚 within an electronic system鈥︹

Expert witness Barbara Lane has previously told the inquiry the construction of the cavity barriers used on Grenfell were 鈥渟ubstantially not representative鈥 of existing test reports for the product and 鈥渃annot be relied upon as evidence of their suitable fire performance in that context鈥.

Asked if he agreed with Lane鈥檚 assessment, Mort replied that the premise of testing cavity barriers is to ascertain their performance in isolation, adding: 鈥淚t鈥檚 the responsibility of the fire engineer on the project or consultants on the project to take all the fire resistance and/or reaction tests for all the elements to come to that conclusion.鈥

The inquiry then heard how Siderise had been marketing a cavity barrier product as suitable for use in rainscreen cladding systems since 2002 based solely on a letter from testing body the Loss Prevention Council which said the barriers would restrict the movement of smoke and hot gases 鈥渁s much as is practical鈥. Siderise did not carry out tests on the product until 2006.

Mort was then shown marketing literature provided to Grenfell cladding subcontractor Harley Facades which claimed that the cavity barriers installed on the tower represented a 鈥減ractical鈥 solution to the 鈥減articularly demanding condition鈥 of rainscreen cladding systems.

The claim was based on assessment reports by testing house Warringtonfire 鈥 but the hearing was told that the phrase had not been used in the reports.

In fact, the reports repeatedly warned of 鈥渟ignificant limitations of use鈥 and made clear that the assessments that had been carried out were 鈥渙nly applicable to the construction that was being dealt with in those tests鈥, Grange said.

Asked if he agreed that the marketing material for the barriers were 鈥渘ot an accurate statement of the opinion that Warringtonfire expressed in any of those test or assessment reports,鈥 Mort replied: 鈥淭hat opinion could have been expressed verbally, I can鈥檛 confirm that.鈥

He added: 鈥淚 work on the technical aspect and the testing aspect of the business, I do not work on marketing. I鈥檓 not a marketeer.鈥

Grange then asked: 鈥淏ut in those circumstances, isn鈥檛 there a risk that what鈥檚 being said in the marketing literature is technically inaccurate or misleading?鈥

Mort replied: 鈥淚 don鈥檛 believe it is misleading. I believe it was a genuine understanding at the time. I don鈥檛 see that as misleading.鈥

The inquiry continues.