A material used in Grenfell Tower’s cladding system known as polyethelene (PE) is so combustible it should not even be put on a bungalow, according to one fire expert looking to ban PE on buildings.
Speaking at the Tall Buildings Fire Safety Network conference in London, Institution of Fire Engineers fellow Merlyn Forrer said he would ban PE in cladding systems.
“I personally would ban PE on buildings,” said Forrer. “I would not even put it on a bungalow”.
Grenfell Tower had Reynobond 55 PE aluminium composite material (ACM) rainscreen cladding, which contributed to the rapid spread of fire across the 67m high tower’s external walls.
The rainscreen cladding used PE, a combustible plastic, between two sheets of aluminium. Manufacturer Arconic has admitted to the Grenfell Tower public inqury that its product “was not of limited combustibility for the purposes of the building regulations”.
Speaking at the same conference, insulation firm Kingspan head of fire engineering services Tony Ryan said it is “very obvious that polyethelene core ACM is a problematic material”. Kingspan insulation was used in some parts of the cladding at Grenfell Tower.
Fire Protection Association director Jim Glockling said the British Standard BS 8414 test, which is used to assess fire resistance of large-scale cladding systems, needs to be more realistic and better reflect real-life scenarios such as vents and openings interrupting firestopping in the cladding.
“Is it worth looking at in terms of improving the way we test things? Yes, almost certainly,” he said.
“At the end of the day we need to accurately replicate the option provision that can occur in practice.”
Currently the government is consulting on a new British Standard, BS 9414, which would be an extension of the current BS 8414 and would contain more detailed information.
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