Chopping down tall timber

UK implements a flammable cladding ban, but hits timber too

Architecture International News
The UK implemented a flammable cladding ban following last year's Grenfell Tower disaster, but the ban hits timber, too. (Natalie Oxford/Wikimedia Commons)
The UK implemented a flammable cladding ban following last year's Grenfell Tower disaster, but the ban hits timber, too. (Natalie Oxford/Wikimedia Commons)

After a fire ravaged the Grenfell tower block in Western London last June, killing 72 and leaving hundreds homeless, an in-depth investigation was launched into the cause of the fire and why it spread so rapidly. After fire specialists BRE Global pointed the finger at the combustible cladding used in the tower’s most recent renovation, England acted to implement a ban on combustible cladding in new structures—a ban that includes timber.

The original Clifford Wearden and Associates–designed tower was built in 1974 with passive fire prevention in mind. However, a 2016 renovation (reportedly to beautify the housing block to improve the views from the wealthier neighborhoods to the south and east) clad the concrete building in combustible polyethylene-cored aluminum panels. Alleged incompetence on the part of the contractors also created a “chimney effect” wherein flames were able to travel upwards through the gap between the structure and flammable panels.

These revelations led the UK’s Ministry of Housing, Communities and Local Government to declare a ban on combustible external cladding for new buildings over 59 feet tall and those that contain housing. Hospitals, dorms, schools, and residential towers would all be affected.

The ban goes into effect on December 21, a full 17 months after the fire. The ban, which would also affect retrofits, effectively limits the materials that can be used as exterior cladding to steel, stone, glass, and others with a European fire rating of Class A1 or A2.

After the final terms of the ban were revealed, the Architects’ Journal reported that London’s Waugh Thistleton Architects, of cross-laminated timber (CLT) proponents, spoke out against the restriction of timber in high rises. Other than slowing the research and development of engineered timber, the ban would disallow the use of a low-carbon cladding alternative.

On the other hand, the Royal Institute of British Architects (RIBA), has seemingly embraced the ban. Adrian Dobson, RIBA director of professional services, released the following statement shortly after the ban was first announced:

“It is good news that the Government has acted on the RIBA’s recommendations to ban combustible cladding on high-rise residential buildings over 18m. The ban needs to be accompanied by clear guidance and effective enforcement to promote fire safety and leave no room for cutting corners.

“However, toxic smoke inhalation from the burning cladding very likely contributed to the disproportionately high loss of life at the Grenfell Tower disaster. Permitting all products classified as A2 does not place any limits on toxic smoke production and flaming particles/droplets. In our view, this is not an adequate response to the tragic loss of life and might still put the public and the Fire and Rescue authorities at unnecessary risk.”

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