Leaked Grenfell report reveals ‘calamitous deficiencies’
THE REPORT, produced by the Building Research Establishment (BRE) and leaked to a newspaper, accounts the fire in ‘forensic detail’.
Evening Standard was leaked the 210 page document, noting that the report has ‘uncovered calamitous deficiencies’ in installation of windows, cavity barriers and cladding systems throughout Grenfell Tower, as well as ‘their failure to meet building regulations’. It found adds, is ‘set to dramatically assist the Metropolitan police’ in their investigations, and accounts in ‘forensic detail’ the issues with the tower after its refurbishment.
It revealed that the fire started in a fridge freezer in a single flat on the fourth floor, ‘travelled through an open window within a metre of the fridge; took hold in the cladding’ and spread from there. Grenfell’s refurbishment ‘failed, in several fundamental areas’ to meet fire safety standards, with the report stating that ‘Grenfell Tower, as originally built, appears to have been designed on the premise of providing very high levels of passive fire protection.
‘The original facade 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’.
‘Deficiencies’ in the cladding façade’s construction ‘provided fuel for the fire to spread’, and the spread happened ‘with such ferocity’ that if the building had been built to ‘less stringent modern standards’ of fire resistance, ‘it is likely the Tower would have collapsed, whether fully or partially’. Five ‘significant’ breaches of building regulations were ‘directly implicated’ in the loss of life.
The first was the cavity barriers, which were of ‘insufficient size specification’ to expand and seal the gaps, with some installed ‘upside down’ or ‘back to front’, and while designed to close a 25mm gap, the actual gap ‘measured up to 50mm’. This resulted in a ‘catastrophic chimney-like effect’ in the gap, which ‘provided a route for fire spread’, while the window frames were ‘significantly narrower’ than the gap between concrete column surfaces, with large gaps at either end.
Gaps were filled by a rubberised membrane, rigid foam insulation and uPVC lightweight plastic panels, but ‘none of the materials used would be capable of providing 30 minutes fire resistance’, allowing for a ‘direct route for fire spread around the window frame into the cavity of the façade […] and from the façade back into flats’. The window frame, the ‘first obstacle’ the fire encountered, instead provided ‘fuel’ rather than a barrier.
Adding to this, the report stated that the ‘construction of the window did not provide any substantial barrier to fire taking hold on the façade outside’, while the ‘combustible’ insulation provided a ‘medium for fire spread up, across and within sections of the façade’. The 75mm insulation foam used on most of the building’s spandrel beams had ‘no markings to identify the manufacturer’, in contrast to the 100m Celotex foam insulation used, with the report not further distinguishing between the types as they were both ‘combustible’.
The aluminium composite material used had a polyethylene core that ‘appears to be highly combustible’ and ‘to have provided a medium for fire spread up and across the façade’, while the ‘absence of door closers’ on many flat front doors resulted in many being ‘inadvertently left open when residents fled’.
In the report, it noted that ‘where this occurred, the fire in each flat appears to have emitted large quantities of smoke and later fire directly into the immediate lobby, and these have gone on to affect the lifts and single stairwell’ – a ‘major failing’ as it created ‘shortcomings in compartmentation’, and would have ‘affected residents’ life chances as they sought to escape down the single stairwell’.
Individual breaches in relation to the cladding ‘assume far greater importance’, the news outlet points out, when the report states that these are ‘considered in combination as opposed to when they occur in isolation’. Added to this, firefighting facilities were ‘deficient’ and ‘hampered’ by poor access, as well as the lack of a wet rising main. There was only room for one appliance on the hard standing at the base of the east side, with other sides inaccessible due to landscaping.
This solitary appliance would therefore be ‘unlikely to provide sufficient pressure and flow of water for firefighting at the top of the tower’ using the dry rising main. The report commented: ‘A building of Grenfell’s height ought to have been fitted with a wet rising main [which contains water at all times] as part of the refurbishment; instead the existing dry rising main [which has to be supplied from a fire engine] was extended and modified.’
There were two other breaches of building regulations identified, including the ‘absence of a sprinkler system’ and the single stairwell being ‘8cm too narrow’, but Evening Standard relates that the report ‘does not necessarily regard these weaknesses as directly responsible for loss of life’, with the report stating that the stairwell would have been ‘difficult and expensive to change as part of any refurbishment’.