The latest guidance on fire safety from The Centre for Window & Cladding Technology (CWCT), has addressed critical fire protection measures, such as compartmentation and curtain wall firestopping. Within the guidance, CWCT’s David Metcalfe also provided further information on changes made to Regulation 7 of the Building Regulations, in November 2018, which introduced a ban on combustible materials in England.
CWCT’s Guidance On Compartmentation & Curtain Wall Firestopping
Within CWCT’s proposals, David Metcalfe states there has been a lack of specific test methods in curtain wall guidance which has resulted in firestops being tested between rigid materials with little consideration of the effect of the curtain wall on the performance of the firestop.
The guidance Metcalfe refers to is Approved Document B (ADB) of the Building Regulations in England which was published in June 2022. He also proposes that references to testing in accordance with BS 476 be dropped from ADB to remove the option for ad hoc testing.
Metcalfe holds the view that the reference to testing in accordance with BS 476 should be dropped because he doesn’t believe it’s likely to involve a scenario which includes a curtain wall, stating: “Such tests generally involve testing the firestop between rigid fire-resisting materials, so are unlikely to represent the performance in conjunction with a curtain wall.”
The issue of testing firestops was discussed by a representative group from the façade industry and fire experts at a meeting in 2022. At the meeting, the CWCT put forward three potential approaches to curtain wall firesopping:
- Test in accordance with EN 1364-4 and use the firestop within the field of application of the test.
- Test in accordance with EN 1364-4 and use the firestop within an extended field of application; can use guidance given in EN 15254-6.
- Detail the firestop based on a fire engineering assessment; this would take account of other mitigating measures – for example, the use of sprinklers in the building and the evacuation strategy.
Updated CWCT Guidance On Combustible Materials Ban
Following the changes made to Regulation 7 of the Building Regulations in November 2018, which implemented a so-called ban on combustible materials, further guidance was released by the CWCT and the Society of Façade Engineering (SFE) after consulting with a wide range of industry professionals in 2020.
It was always the intention to update the document, with feedback from readers encouraged from the start. The revisions began in 2022 and up to this point only minor tweaks have been required, with the CWCT providing its own guidance on the combustible materials ban:
“While the exemptions acknowledge the vital role that certain combustible materials currently play in the performance of modern façades, it is important to recognise that the industry has responded to the ‘ban’ and developed new materials that meet the regulation. Where such materials exist without compromising other aspects of performance, it will almost always be appropriate to use them in preference to a more combustible alternative.”
Birwin Architectural Undertaking CPD Fire Safety Training
In addition to our commitment to adhering to all regulations and guidance from the Building Regulations and CWCT, we are currently in the process of fire-safety-related CPD training. We’ll keep you posted with this and more in our news section and across our social media channels.