Grenfell Tower’s cladding did not comply with building regulations, was badly installed and created routes for a fire to spread, a damning report into the blaze has concluded.
Five fire safety experts have been examining the fire in which 82 people died and today gave their views on how the fire started, how it spread and why so many people were killed.
Dr Barbara Lane, an expert commissioned by the Grenfell Tower inquiry, delivered an excoriating assessment of the refurbishment which finished a year before the fire.
The rainscreen cladding put on the building used material that did not meet fire safety standards, while the system as a whole was not capable of effectively preventing the inferno spreading, she found.
The cladding on the outside of Grenfell Tower was to blame for the fire spreading
Another expert, Professor Luke Bisby, found a series of problems with refurbishment work carried out on Grenfell before the fire.
Prof Bisby said the main reason the fire spread was the polyethylene-filled ACM rainscreen in the cladding.
He also said combustible insulation, the presence of cavities and the use of combustible window frames added to the spread of the blaze.
Prof Bishby also identified the lack of cavity barriers between sections of the cladding, a ‘crown detail’ which helped the fire spread sideways and exposed parts of the combustible core added to the fire.
In her report meanwhile, Dr Lane found there was also no evidence they had ever been tested for performance in the cladding system.
She wrote: ‘There were multiple catastrophic fire-spread routes created by the construction form and construction detailing.’
A photo shows the softened uPVC finish revealing the cavity and combustible insulation board within in living room in flat 16
Shocking footage shows how a fire which started in a kitchen of a Grenfell Tower flat leapt up the side of the building .An image taken from footage filmed around 1.28am (right) shows how, aided by what a report called ‘multiple catastrophic fire-spread routes’, the fire reached the top
Windows in individual flats had no fire barriers encasing them and these openings were surrounded by combustible material, the expert found.
Such a shortcoming ‘increased the likelihood of that fire breaking into the large cavities contained within the cladding system’ and provided ‘no means to control the spread of fire and smoke’.
The gap beyond the window, in turn, was supposed to have fire-stops at intervals which would halt the advance of flames – but these were installed incorrectly.
Any fire which started near a window therefore had a ‘disproportionately high probability’ of spreading into the rainscreen cladding, Dr Lane concluded.
The link between the kitchen window and the rainscreen cladding system on both the column and above the windows was the ‘primary cause of the early stage of the fire spread’, she said.
The cladding itself – Reynobond 55PE – contributed to the ‘most rapid’ of the fire spread, the report said.
Dr Lane said: ‘The assembly – taken together with the insulation material on the existing external wall, the missing and defective cavity barriers – became part of a successful combustion process.’
Five pathways were created through which a fire could spread, meaning each flat was ‘no longer’ a fire-safe box, instead the whole building was at risk.
When a blaze took hold on June 14, it caused multiple internal fires, multiple fires on entrance fire doors and large quantities of polymeric-based smoke which crept into flats and lobbies.
A detail from a report shows the cladding on the building which helped the fire spread
Fire safety experts Dr Barbara Lane and Professor Luke Bisby both blamed the cladding
This required smoke-control in multiple lobbies, firefighting efforts on multiple floors and on the exterior of the building, the need for a change of the evacuation strategy and the need for disabled residents to self-evacuate ‘for which no facilities were provided within the building’.
The scale of the cladding’s shortcomings never appears to have been grasped by any of the key bodies linked to the refurbishment.
Dr Lane wrote: ‘I have found no evidence yet that any member of the design team or the construction ascertained the fire performance of the rainscreen cladding system materials, nor understood how the assembly performed in fire.
‘I have found no evidence that Building Control were either informed or understood how the assembly would perform in a fire.
‘Further I have found no evidence that the (Tenant Management Organisation) risk assessment recorded the fire performance of the rainscreen cladding system, nor have I found evidence that the LFB risk assessment recorded the fire performance of the rainscreen cladding.’