A combination of polyisocyanurate (PIR) insulation with an unmodified polyethylene-filled ACM cladding panel has failed the first large-scale fire resistance test of insulation following the Grenfell Tower Fire in late June.
The British Rigid Urethane Foam Manufacturers Association (BRUFMA) has responded to the test carried out by the UK BRE organisation saying that the result is ‘as expected.’
BRUFMA said ‘this combination of materials does not meet building regulations and would never be recommended or approved for use by the members of BRUFMA in a real building.’ BRUFMA added that it is ‘advisable to wait until all six tests are complete before any meaningful conclusions can be drawn and solutions proposed.’
The organization said that a full analysis of all the results should be conducted together and ‘from this, clear guidance will be issued as to which combinations of insulation and cladding are acceptable in relation to the current regulations. Only in this way, will the government be able to demonstrate the safety of buildings and provide an accurate picture to the owners and residents across the country.’
Simon Storer, BRUFMA chairman, said "the result is as expected and therefore it is worrying that a number of buildings have been identified with this combination, indicating a lack of compliance to existing rules and regulations."
The United Kingdom Department for Communities and Local Government (DCLG) said that currently 82 buildings in the U.K. are known to have the combination of PIR board and non-fire retardant polyurethane/metal cladding combination of materials in their wall cladding systems and 47 of which are local authority or housing association owned or managed.
According to the DCLG, which is responsible for the tests, each test involves building a nine-meter-high demonstration wall with a complete cladding system including panels, insulation and cavity barriers. This is then subjected to a replica of a severe fire inside a flat as it spreads out of the window to see whether it meets the requirements to resist vertical fire spread. The tests, are being carried out at BRE, formerly the Building Research Establishment and are looking at the flame retardancy of systems which include:
• ACM with unmodified polyethylene filler with PIR.
• ACM with a fire-retardant polyethylene filler with PIR; and finally.
• ACM with limited combustibility filler with PIR.
The tests are being repeated with mineral wool in place of PIR insulation.
DCLG said that the tests will result in a series of data that will determine whether the wall systems pass requirements of building requirement regulation BR135. If the combination fails the test then then that specific combination of materials would not meet current building regulations guidance and is unlikely to be safe for use on high-rise buildings.
DLCG hopes to have all of the six tests completed in the week of 14 Aug.
The Grenfell Tower, is located in the Royal Borough of Kensington and Chelsea, a local authority to the west of London. It was the site of a fatal fire in late June. Investigations are underway into the 79 deaths which have so far been attributed to it. London’s Metropolitan Police said that the investigation could last for years and that it is the largest ever carried out outside of terrorism.