A further 22 UK buildings have “failed” the latest round of large-scale combustibility tests, undertaken following the Grenfell Tower fire.
After the Grenfell Tower fire on 14 June, the government began a fire safety testing programme led by materials testing organisation BRE. It has tested hundreds of aluminium composite material (ACM) cladding samples and six large-scale cladding combinations for compliance with fire safety guidance set out in the Building Regulations 2010.
Since the testing programme started, more than 269 cladding samples have now failed, along with four of six large-scale test combinations. An independent review of current building regulations and fire safety in tall buildings is to be carried out as a result, led by manufacturing trade body EEF’s chair Dame Judith Hackitt.
Initially six large-scale tests were announced, before the Independent Expert Advisory Panel recommended a seventh test combining ACM cladding containing fire retardant polyethylene filler (category 2 in screening tests) with phenolic foam insulation.
These results are from the seventh test: for practical reasons results for the seventh test have been published before the sixth. Twenty two buildings over 18m tall are known to have this cladding combination.
Large-scale cladding combinations are being tested for compliance with building regulations under the second route for compliance. This test follows criteria set out in British Standard 8414-1, and the results are checked for compliance with BR135. During the test, a 9m high cladding system is built and then burnt to test how fire spreads across the surface.
To comply with BR135, a test must last for at least 40 minutes. However, the latest test had to be terminated after 28 minutes and 14 seconds because flames had spreading above the testing apparatus. If a test has to be terminated early, the results cannot be assessed against BR135, and therefore the cladding system is deemed to have failed.
Results for the final large-scale test will be published shortly.