June 15, 2017 — With 72 confirmed dead but dozens of people still missing in London’s 120-apartment Grenfell Tower

Around 500 people were in the building when the blazes started on the fourth floor – as many as 200 people are missing.

Design specifications seen by the Press Association suggest the renovation work carried out at Grenfell Tower included plans for aluminum cladding with a 50mm “ventilated cavity” to vent moisture next to 150mm of Celotex FR5000 insulation, which has a Class 0 rating — the highest rating for preventing the spread of flames.

Grenfell Tower, London
Grenfell Tower, London

Fire investigators are focusing on the cladding. Experts believe this may have failed with the void between the aluminum panels and building ACP acting as a chimney and fuel to spread the fire.

The aluminum composite panel cladding (ACP) is basically made of three layers, out of which two layers in front and back is aluminum sheet and the middle layer is polyethylene. Polyethylene is a high flammable petroleum product

Under severe fire conditions, timber chars, concrete spalls, steel melts, glass breaks.

But Polyethylene, is a plastic, a petrochemical product. It behaves differently than most building materials.

It is fuel !! ….and it burns !!!

Tall building façades clad with ACP panels which have polyethylene core can potentially transfer a fire, very quickly from one floor to the next, with terrible consequences.

Equipped with this basic understanding of envelope science, you’ll be able to take your knowledge into the field and prevent possible failures.

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