How to Spread Fire on the Exterior of a Building

The Greenfell Tower was a 24-story building in London, designed and built in what is called the Brutalist Style. This architectural style flourished from the early 1950’s until the mid 70’s and is comprised of raw concrete or brick in a blunt layout and lacking ornate features.

It doesn’t sound like the sort of building whose exterior could be completely engulfed in flames in 30 minutes but that’s exactly what happened on June 14, 2017. The blazed burned for 60 hours and required the efforts of 250 firefighters to bring it under control. It was the worst United Kingdom residential fire since the Second World War and resulted in 72 deaths, 70 others injured, with an additional 223 escaping the conflagration.

Starting two years before the fire, a major renovation was started, part of which was the addition of a new composite cladding to the building’s exterior. The cladding’s purpose was to help heating and energy efficiency and to soften the look of the tower’s rough exterior. This material was composed of two aluminum sheets bonded to a flammable polyethylene core, chosen because it saved approximately $385,000 on the $12 million renovation.

A fire in 2009 which spread unexpectedly quickly due to exterior cladding and caused 6 deaths prompted fears about the potential for other fires, however no urgent actions were taken by the government. Another fire, also spreading quickly due to external cladding, took place in 2016.

The Greenfell Tower suffered from other concerns. Residents attempted to bring to the attention of the building’s management company as well as local government details such as firefighting equipment at the tower that had not been checked for up to four years, including on-site extinguishers which had expired. They never received a reply. In addition, the building had only one stairwell and one exit, as United Kingdom regulations do not require a second. Also, building corridors had been allowed to fill with a variety of obstructions and debris, such as old mattresses.

One year before the fire, an independent assessor highlighted 40 serious issues concerning fire safety that were deemed to require immediate action, however by October the assessor contacted the management company to inquire why over 20 of the issues hadn’t been tackled. Then in November, the London Fire and Emergency Planning Authority served the management group with a “fire deficiency notice” which required action by May 2017.

Very early in the morning of June 14, 2017, fire from a refrigerator broke out on the 4th floor.

Timeline of Greenfell Tower fire12:50 BST (British Summer Time) – fire breaks out shortly after midnight

12:54 BST – fire department called, first crews arrived six minutes after alarm

1:07 BST – responders enter the apartment

1:09 BST – fire had reached external cladding by erupting out of apartment window

1:14 BST – fire fighters start attacking the initial fire. A fire fighter outside tried to prevent the spread but the spray of water couldn’t reach higher than the 4th floor. The cladding’s manufacturer recommended not using the material on a building taller than 3 stories – the Greenfell Tower was 24 stories tall.

By the time fire fighters had the initial fire under control, flames were advancing quickly up the building.

1:29 BST – a rising column of flames had reached the roof and the fire was out of control. Other residents who had called the fire department were told to stay in their rooms, which is standard policy for a fire in a high-rise building relying on the assumption the fire can be contained in one area. Also, as part of this policy, the building had no central fire alarm system which could warn all residents to evacuate.

The fire burning on the cladding spread horizontally and re-entered the building through other windows

1:30 BST – the single stairwell became filled with smoke, making it difficult for residents to escape without help from fire fighters

5:00 BST – the building was still burning. All residents up to 10th floor had been rescued, but firefighters had not been able to get any higher than the 20th floor. Only 2 people escaped from the two highest floors

13:14 BST – fire brought under control

The fire prompted massive investigations into other potential fire risks of buildings covered with cladding, as well as criminal investigations against the building’s management company. Plans are to demolish the building by the end of 2018.

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