A type of lightweight aluminum cladding made by Arconic (formerly known as Alcoa) has been discontinued after being linked to the deadly fire that claimed at least 79 lives at the 24-story Grenfell Tower in London.
The fire began as a refrigerator fire in an apartment on the fourth floor of the building. The fire from this low-situated apartment spread to the exterior, which had recently been clad in Arconic’s Reynobond PE panels. This product sandwiches flammable polyethylene between two thin sheets of aluminum.
As the NY Times reports, while the panels flamed, a two-inch air gap between the cladding and the insulation attached to the old wall created a chimney effect, causing the heat, flames, and smoke to rise rapidly and engulf the building, which already lacked smoke alarms, sprinklers, and fire escapes. As the fire rose, it punched its way into the tower’s interior.
The BBC reports that Aronic has confirmed it has stopped sale of Reynobond PE for high-rises, citing concerns about the “inconsistency of building codes across the world.”
Cladding, both from Arconic and others, has been widely used on low-income housing in the UK in recent years, in an apparent attempt to beautify older structures as London and other cities become more gentrified. The UK government has identified around 600 housing towers that have questionable cladding. It has already performed safety test on at least 75 properties, with all of them failing. This has resulted in multiple buildings being evacuated for residents’ safety.
In the U.S. the Reynobond PE cladding is not authorized for use on buildings more than 40 feet tall, but it has been used on taller buildings in London and elsewhere around the world. Whether it meets UK safety standards has been a matter for debate, notes the Wall Street Journal, with some officials saying its use should have been limited to buildings below 60 feet while some contractors argued that it was fine for taller structures.
What’s more, the UK does not require real-world fire safety testing of cladding products for high-rise buildings. Contrast that to the U.S., where the product must be tested as it would actually be installed on a building. Such testing in the UK could have shown that even if the aluminum prevents the fire from penetrating to the polyethylene core, the flames could spread along the surface of the aluminum.
“If the cladding cannot resist the spread of flame across the surface, then it will vertically envelop the building,” a fire safety adviser to the firefighters’ union told Parliament before the Grenfel Tower fire. “In other words, the fire will spread to the outside of the building, and it will go vertically.”
The Times points out that lawmakers in the UK have, for years, pressed safety regulators to officially bar the use of flammable cladding at heights beyond the reach of a firefighter’s ladder, but officials instead chose to listen to developers who said that requiring only non-flammable materials on high-rises “limits your choice of materials quite significantly.”
In 2005, Parliament passed the Regulatory Reform (Fire Safety) Order, which shifted the burden for fire safety inspection from the government to business and property owners.