What we learned

‘Stay put’ policy



The ‘stay put’ policy failed by 1.26am, according to Dr Barbara Lane, the leader of fire safety engineering at Arup in her evidence, but it was only changed to evacuate by the London Fire Brigade at 2.47am, by which time dozens of the flats were on fire. One hundred and seven people were still inside and only 36 of them ever got out.

Grenfell inquiry: fire service advice to 'stay put' failed residents – as it happened Read more

Lane said “there was a total failing of the principles of stay put”. She said some lobbies had become clogged with black smoke by 1.20am and the stairway was smoke-filled by 1.40am. Yet the policy remained in place for another hour and seven minutes, during which conditions in the lower part of the tower were deteriorating fast. The stairways around level 10 were described as “boiling hot” around that time.

“Why was the formal stay put policy maintained until 2.47am and not revoked earlier?” asked Richard Millett QC, counsel to the inquiry. “How did the change of strategy get communicated to residents?”

Lane said changing stay put policies in the UK is not easy because there is no statutory obligation to provide an automatic detection and alarm system in all high-rise buildings for the purposes of warning occupants that an immediate evacuation is required. At Grenfell, there was no fire control panel through which the London Fire Brigade could have communicated to the people inside that they had to get out, she said.

Millett said there were fire notices in lift lobbies urging residents to stay put, which raised the question of why 144 people evacuated before 1.38am.

Cladding

At 1.14am on 14 June firefighters in breathing equipment got into flat 16 and tried to extinguish the fire where it started in Behailu Kebede’s kitchen. It was 20 minutes after he had dialled 999, but the cladding was already alight and within a quarter of an hour, all 23 storeys were on fire. Experts told the inquiry, the uPVC window frames appeared to have melted, exposing combustible materials within them before catching the flammable core of the rainscreen cladding outside the window. This system of combustible cladding panels and insulation was “substantially to blame for the tragedy” and was “non-compliant with the functional requirement of the building regulations”, Lane found.

Play Video 2:33 Video timeline shows how the Grenfell Tower fire unfolded

Grenfell inquiry video shows speed at which fire spread to cladding Read more

As well as the combustible aluminium composite material panels and the combustible insulation, Prof Luke Bisby of the University of Edinburgh’s school of engineering identified a large number of other materials that burn. He found a polyurethane polymer foam insulation board that predated the refurbishment that may have had a role in spreading the fire. It was observed alight by a firefighter. There was polymeric spray foam used during the refurbishment. Combustible synthetic rubber was also used to join the new uPVC window frames to the original concrete structure and the melting of those window frames and polymer infill panels between windows do not appear to have been fire tested and are likely to have been combustible, he said.

Lane found the cladding produced toxic smoke that slowed down the firefighters because they had to wear breathing apparatus and “the ultimate consequence was a disproportionately high loss of life”.

She said: “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.”

Neither did she find evidence that building control at the Royal Borough of Kensington and Chelsea was 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.”

Fire doors

One hundred and six of the 120 apartment front doors were replaced in 2011. They were fitted with all sorts of different locks, hinges, letter plates and self-closers that can significantly reduce the amount of time the door can resist fire. Forty-eight of them included glazing that wasn’t accounted for by the fire test data and this glass failed prematurely allowing flames and smoke to vent directly through. Fourteen of the doors to flats owned by leaseholders were of unknown origin and were completely destroyed in the fire and none of the front doors from floors four to 23 met building regulations, Lane concluded.

Smoke and flames were able to spread between the doors and the door frames and an unknown number of self-closers failed, preventing the compartmentalisation of the fire. Some of the fire doors to the single stairway that should have withstood the fire for 60 minutes failed within 20 minutes and were sometimes propped open by firefighting hoses and, in one case, a dead body.

Fire lift

Grenfell Tower’s lift was designed to have a feature that allowed it to be used as a fire rescue lift, but it did not work. The “failure of the lift to perform as intended is a matter of very serious concern”, said Millett.

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It delayed firefighters getting to the flat where the fire started and “might have increased the chances of extinguishing the fire before it spread externally”, said Lane. Its failure also prevented the firefighters getting equipment higher up the building.

“All operations by the fire service within the 23 storeys were therefore required to be by means of walking up and down the stair only,” she said.

Smoke ventilation

The building had a system for removing smoke from the lobbies, but this was a “bespoke” design and was not compliant with building regulations, said Lane. It did not operate as intended, and attempts by firefighters to take control of it failed. If it had have worked, firefighter might have been able to use it to clear smoke from the lobbies floor by floor. The inquiry heard that the heat in the lobbies would have caused “immediate pain” to exposed skin and that was putting residents off from trying to leave their flats, the “thick black smoke” prevented firefighters from being able to use lobbies as a bridgehead or search base. There was a “hot spot zone” between levels 13 and 16, and smoke entered the stairway from open doors to the lobby. Firefighters could have contributed to this by leaving doors open in firefighting efforts.

Water supply

Water supplies to firefighters in Grenfell Tower failed during the blaze because the main riser pipe system was out of date, Lane said. The building was equipped with a dry main riser in the lobby rather than a more effective wet main riser which later guidance said should have been in the stairwell. There were no problems initially for firefighters seeking water to extinguish the blaze in flat 16 on the fourth floor of the building but later on problems became apparent.

“In a wet riser, the system is already charged with a pump connected when the fire service arrives. A wet fire main could have enabled a faster initial response time to the fire in Flat 16 which might have increased, the chances of extinguishing the fire before it spread externally.”

However, that statement was at odds with evidence given on Monday, which said that flames had already ignited the external cladding before firefighters entered the kitchen of flat 16.

Lane’s report also found that a wet main riser would have provided greater water pressure for firefighting in the upper floors of the tower. It would have “allowed the fire service to use water to cool the lobbies and stairs and therefore provide more assistance to people trying to escape”, she said.

“While the dry main riser failed for the fire service in controlling fire and smoke spread in the lobbies and stairs, and particularly on the upper levels, the wet fire main could also have failed to provide sufficient water and pressure to control smoke and fire spread once more than two hoses were in operation.”