Month: April 2018

Grenfell Tower: Why, in 1995, did the BBA see no additional hazard in using combustible render rather than non-combustible?

In my last post, I introduced an Agrément Certificate issued by the British Board of Agrément (BBA) to Sto in 1995 for an External Wall Insulation System. Examining the version of the system with combustible Expanded Polystyrene (EPS) insulation, I first questioned the basis on which it had been granted a Class 0 Reaction to Fire rating (Detail Sheet 2):

Then I expressed alarm that the BBA granted approval for the system to be used at any height:

in apparent direct contravention of the restriction, introduced into Approved Document B in 1992, of the use of combustible insulation to buildings of 20 metres or lower:

I sent an email to the BBA on 15 April to ask whether they now believed the Certificate was issued in error, but have not so far received a reply.

Continue reading Grenfell Tower: Why, in 1995, did the BBA see no additional hazard in using combustible render rather than non-combustible?

Grenfell Tower: Why, in 1995, did the BBA approve combustible insulation for use on high rise residential buildings?

The British Board of Agrément is the leading British certifier of construction products and systems. It was originally named the Agrément Board, after a similar system pioneered in France by the CSTB (Centre Scientifique et Technique du Bātiment). The Director of the CSTB was invited (p. 62) to speak about that organisation at a special meeting of the Royal Institute of British Architects in 1963, and Geoffrey Rippon, the Construction Minister accepted a recommendation to establish a similar system in Britain.  It was established in 1966 as a limited company controlled by the government, and was accordingly long referred to as a non-departmental public body. Its first two objects, as laid out in its Memorandum of Assocation, were to assess materials, products, systems and techniques for use in the building industry, and to grant certificates for them:

Continue reading Grenfell Tower: Why, in 1995, did the BBA approve combustible insulation for use on high rise residential buildings?

Grenfell Tower: Exova’s approval in 2012 of the use of combustible ACM for high rise cladding

In my last post I introduced a Certificate of Approval, issued in 2012 by Exova, trading as Warrington Certification, for a combustible FR grade ACM panel. According to the government’s post-Grenfell interpretation of Approved Document B2, 12.7, this certificate should not have been issued, since the panels fail to meet the limited combustibility requirement of that paragraph.

The certificate bore on every page the signature of Sir Ken Knight, who is Chair of the Grenfell Tower Expert Panel. This body claimed on 30 June 2017 that the Buildings Regulation guidance requires the ACM core to be of limited combustibility. The text of the Approved Document guidance on cladding has remained unchanged since 2007. It follows that the Expert Panel must be of the view that the certificate was issued in error.

Continue reading Grenfell Tower: Exova’s approval in 2012 of the use of combustible ACM for high rise cladding