The recladding of Grenfell Tower failed to meet safety standards set out in Approved Document B – the building regulation covering fire safety – and helped spread the fire, according to a report commissioned by Metropolitan Police investigators
A copy of the 210-page draft document, which was leaked to the Evening Standard, outlines a number of deficiencies in the installation of windows, cavity barriers and the cladding system between 2014 and 2016.
These failures on the job fuelled the spread of the fire that resulted in 71 deaths in June last year, the report concluded.
According to the Standard, the report said: ‘Grenfell Tower, as originally built, appears to have been designed on the premise of providing very high levels of passive fire protection.
’The original façade of Grenfell Tower, comprising exposed concrete and, given its age, likely timber or metal frame windows, would not have provided a medium for fire spread up the external surface. In BRE’s opinion … there would have been little opportunity for a fire in a flat of Grenfell Tower to spread to any neighbouring flats.’
According to the newspaper, the report said that the aluminium composite material used for the cladding had a polyethylene (plastic) core that ‘appears to be highly combustible’.
The report also found that cavity barriers designed to expand and seal the gap between the cladding and the building were of ‘insufficient size specification’ to work properly.
Crucially, the dossier reveals there was a 150mm gap between window frames and the concrete columns holding them, which had been filled with a rubberised membrane, rigid foam insulation and uPVC lightweight plastic panels, none of which would have provided 30 minutes fire resistance.
In addition, many flat doors lacked closers, contrary to Building Regulations, meaning that large quantities of smoke entered the stairwell and lifts.
The Evening Standard reports an unnamed ‘specialist architect’ shown the draft report as saying: ‘The question is: could this fire have been avoided? This damning report is saying it absolutely could have been and that the refurb was to blame … But the report has left open the vital question as to whether the design or the installation was at fault, whether the works were approved and/or inspected, or whether it was a combination of all of these.
‘The buck stops with the owner of the building Kensington and Chelsea Council, and its management organisation, which have ultimate duty of care.’
The report was carried out by the Buildings Research Establishment (BRE) on behalf of the police investigation into the fire.