Grenfell Tower had “multiple catastrophic fire-spread routes” which were created during cladding construction, a report has concluded.
A series of damning reports on the fire safety of Grenfell Tower have just been published as part of the ongoing inquiry into the tragedy.
Arup’s leader of fire safety engineering, Dr Barbara Lane, one of the expert witnesses in the Grenfell Tower Inquiry, has released her findings. Alongside the cladding, there are a number of failures raised, including internal doors and flat front doors, a dry fire main and the lift switch to firefighter mode not working. Lane’s findings include:
- “There were multiple catastrophic fire-spread routes created by the construction form and construction detailing,” regarding the rainscreen cladding system.
- Consequence of cladding type and assembly meant that “any individual flat of fire origin was no longer in a separate fire rated box” and therefore a stay put strategy for residents in the event of a fire was “not a realistic basis for fire safety design in this building, as a result of the rainscreen cladding system.”
- “I have found no evidence yet that any member of the design team or the construction team 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.” She said she is awaiting further evidence on this issue.
- The cavities which should have prevented flames spreading between floors were installed incorrectly on both horizontal and vertical levels.
- The Stay Put stratergy failed one hour before the building was evacuated. There was an “early need for total evacuation of Grenfell Tower […] I am unclear about the basis for delaying the formal end of the Stay Put strategy between 01:40 and 02:47. I am particularly concerned by the delay from 02:06 when a major incident was declared, to 02:47.”
- The fire originated in Flat 16, however it “could not maintain the required high degree of compartmentation due to the failure of the building envelope to adequately resist the spread of fire.”
- “The single stair and lobbies, and the fire provisions therein, were not designed to create a safe escape route or safe working environment, for a multi-storey fire. The design approach for high rise residential buildings is based on inhibiting that scenario from occuring.”
- “All the flat entrance fire doors (from Level 4 - 23) were non-compliant with the fire test evience relied upon at the time of the installation. […] these doors do not appear to have been upgraded since the original installation in 1972.”
The inquiry into the fire at the 24-storey Grenfell Tower in North Kensington, London, in the early hours of 14 June 2017, is split into two phases, which will run in parallel.
The first examines what actually happened in the early hours of the morning when the fire broke out. The second phase looks at the refurbishment and how the building was exposed to such a fire risk.
Like what you’ve read? To receive New Civil Engineer’s daily and weekly newsletters click here.