Expert rejects government position on flammable cladding in Grenfell Inquiry evidence

News04.06.182.30 PM by Peter Apps

An expert fire engineer has called for urgent changes to official guidance on fire safety, as she disputed the government’s claim that flammable cladding is banned.

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Grenfell Inquiry hears from expert fire engineer who rejects the government’s claim that flammable cladding is banned. #grenfellinquiry #ukhousing

A report by Dr Barbara Lane, a chartered fire engineer, and UK leader for the Applied Innovation and Technology Group at Arup, was released by the Grenfell Inquiry today.

It dismisses the argument put forward by ministers since the fire that building regulations guidance required cladding panels to be of ‘limited combustibility’ and calls for the guidance to be urgently amended.

The ‘Class 0’ debate explained

Since the Grenfell Tower fire, the government has insisted that its official guidance, Approved Document B, required cladding panels to be of ‘limited combustibility’. But many industry figures disagree, saying that the standard the guidance set was ‘Class 0’ or ‘Euroclass B’.
Approved Document B sets limited combustibility as the standard for ‘insulation materials/products’ in paragraph 12.7. It sets Class 0 or Euroclass B as the standard for ‘external surfaces’ in paragraph 12.6.
Paragraph 12.7 says that “insulation product, filler material etc” must be of limited combustibility. In a letter to social landlords on 22 June, the government said that the word ‘filler’ in this context covered the plastic in between the aluminium sheets in the cladding.
But experts have disputed this view, pointing out that the cladding itself does not have an insulation function.
The cladding used on Grenfell was certified to Class 0 and so would apparently have met the official standard for external walls.
This debate remains crucial in assessing the liability for the removal of cladding, much of which is also rated Class 0, from hundreds of tower blocks nationwide.

She wrote: “I am aware that there is a range of opinion on this issue and others consider that the core in an [ACM] is now filler and therefore dealt with under the provisions made for insulation.

“For the reasons I have set out above, I disagree with this view.”

She added that Diagram 40 in Approved Document B should be amended to remove reference to allowing materials lower than limited combustibility to be used on the external surfaces of high rises.

“I would go so far as to suggest this should extend to any building containing a sleeping risk, such as hospitals,” she adds.

The government has repeatedly denied this interpretation of building regulations, dating back to an interview by Philip Hammond with the BBC just days after the fire.

However, she says that testing reports provided to her by Arconic, the manufacturer of the cladding, show the material on Grenfell – Reynobond 55 PE – did not even meet the lower standard of Class 0, and was in fact Class E.

Despite this, the product was certified to Class 0 by a British Board of Agrement licence, valid at the time of the fire.

Dr Lane’s report was contradicted by another expert witness, Colin Todd, managing director of CS Todd Associates, also released today.

He wrote: “The inquiry may be aware that since the Grenfell Tower fire, there has been contention as to whether this term [filler material] applies to the core of [ACM], though, in my opinion, it would be somewhat illogical for it not to do so.”

The Ministry for Housing, Communities and Local Government (MHCLG) has been contacted for comment.

The Inquiry, which heard opening statements today in central London, continues.