Fire experts have slammed the “utter inadequacy” of laboratory tests in a report examining safety standards in the aftermath of the Grenfell Tower tragedy.
Cladding was sometimes tested in a sealed unit but fitted on a building it would often include gaps, the research by the Fire Protection Association into British Standard test BS8414 for the approval of cladding systems found.
“In voids that can exist behind some cladding systems, the speed of the fire spread can be increased by a chimney effect.
“Any tests which restrict the availability of oxygen in a way that doesn’t happen on a full-scale building will not be able to correctly assess how the materials will behave in practice,” the report, published today, said.
Some test fires are only made up of wood, whereas modern fires involve 20% of plastic materials, according to the report commissioned by the Association of British Insurers (ABI), and materials tested will be in manufacturer condition but in their actual use will be pierced by vents or ducts.
Fire Protection Association managing director Jonathan O’Neill said: “The results of this important research confirm long-held concerns by many in the fire sector that the current cladding test standard requires urgent review to ensure that systems that pass are reflective of the systems that are installed and of the risks to which they are exposed.
“We urge the British Standards Institution to urgently reconvene the group responsible for this standard to consider the results of this research and to make changes to the standard as required.”
The British Standards Institution said: “We were notified that the FPA intended to undertake this research work on behalf of the ABI and agreed from the outset that we would share any findings with our standards committee – FSH/21 - for their review.
“If the committee view is that the changes are supported by the evidence and are technically feasible, they will work together to amend the standard. In this case, the process from review to publication will take up to 18 months including a period of time for public consultation.”
The Royal Institute of British Architects (RIBA) called for a ban on flammable cladding on high rise buildings, which it said had been overlooked in the Hackitt Review into building regulations following the fire that killed 71 people in June last year.
A BRE Global report, leaked to the Evening Standard last week, concluded that the fire would have had “little opportunity” to spread from the flat it started in, had it not been for the recladding and other works carried out between 2014 and 2016.