Grenfell fire inquiry told of safety flaws introduced over more than decade

A litany of fire safety flaws introduced at Grenfell Tower over more than a decade have been set out at the inquiry into the disaster.

Dr Barbara Lane, an expert witness who analysed the fire for Sir Martin Moore-Bick's investigation, said fire lifts and fire mains within the building were not suitable.

She is one of four specialists due to give evidence about the inferno this week.

Work done on the lifts in 2005 and 2012-16 left them unfit for evacuating the building of vulnerable residents and aiding the emergency response, Dr Lane said on Monday.

They lacked features including an escape hatch, a secondary power supply or doors that can resist a fire for 60 minutes, as outlined in Approved Document B of the building regulations, it was heard.

The block's dry rise system - pipes through which the fire service pump their own water into the building - was also said to go against statutory guidance.

Dry rises rely on good water pressure to work against gravity, unlike wet mains, which summon water from a pressurised tank already within in the building.

Dr Lane, a chartered fire safety engineer and director at specialist design group Arup, said: "Eventually a height is reached where the water pressure that can be delivered by a dry main cannot effectively operate a fire hose.

"For this reason, the statutory design guidance limits use of dry mains to buildings less than 50 metres in height.

"For a building that is 50 metres or more in height, there is a requirement to provide a wet fire main."

Grenfell Tower was 67.3 metres in height, Dr Lane's report said.

Putting the failures in context, the expert said an effective firefighting lift counts as an "active" safety measure, while a fire main is a "defence in place" measure.

Fire doors and fire-resistant walls - both replaced in some form at Grenfell Tower in 2011 and 2016 respectively - count as "passive" safety measures.

The "very basis" of a stay-put policy requiring residents to remain inside during a fire, like that in place at Grenfell Tower, was these three measures working successfully, she continued.

They ensure the fire does not spread beyond the flat of origin, therefore not requiring an evacuation and making it easier for firefighters to tackle the blaze.

Dr Lane's report, published a fortnight ago, said all of the flat entrance fire doors did not meet building regulation standards.

In 2011, 106 out of 120 fire doors at flat entrances were replaced with a model known as Suredor GRP, designed by Manse Mastedor.

The expert told the hearing at Holborn Bars: "Fire doors are a crucial element of the stay-put strategy, as they represent an opportunity for weak spots to form in the fire-resistant partitions that separate a flat fire from occupants either on that floor where the fire has started or occupants in the flat above the floor the fire has started.

"Fire doors are, therefore, a building regulations requirement as a passive fire protection measure. Faulty fire doors mean faulty compartmentation and compartmentation is the primary basis of the stay-put strategy."

Residents in the west London block were told to remain in their flats for almost two hours after the fire broke out, a decision which it is feared led to the disaster being so costly.

"The statutory guidance makes no provision within the building for anything other than a stay put strategy," Dr Lane said.

During a detailed presentation, the original construction of Grenfell Tower was also outlined.

The 24-storey structure was built with walls that were "entirely non-combustible", meaning a "single system with no void or a space within the exterior wall".

The replacement of the building's cladding system, completed in 2016, saw flammable material installed on the exterior, with a cavity between the wall and the insulation.

The building regulations require that exterior walls prevent the spread of flames, the inquiry was told.

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