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Closing the Compliance Gap: Fire Regulations for EPDM Roofing

By Holrow Limited in Industry News

Guidance from Holrow

At Holrow, we believe it is essential that specifiers, contractors, and building owners fully understand the latest fire safety regulations. Only with clear knowledge can they make informed decisions about which flat roofing products offer the highest levels of safety and compliance.

In the wake of the Grenfell Tower fire in 2017, the importance of specifying fire-safe building products has never been greater. Flat roof waterproofing systems must comply not only with the Building Regulations, but also with European fire testing standards. These requirements can appear complex, so this guidance provides clarity on the regulations and explains why EPDM flat roofing systems are a safe and reliable choice.

Understanding Fire Ratings

BS 476: Part 3: 2012 & BS EN 13501-5 For many years, the UK used BS 476: Part 3: 2012, which assessed a flat roof’s resistance to external fire exposure — specifically “spread of flame” and “penetration of flame.” The highest classification achievable was EXT.F.AA.

Since 2018, the UK has transitioned to the harmonised European standard EN 13501-5:2016. This introduces four possible classifications for roof systems exposed to fire: Broof(t1), Broof(t2), Broof(t3), and Broof(t4).

Why Broof (t4) Matters

Of these classifications, Broof (t4) is the most demanding, and it is considered the closest equivalent to the old UK EXT.F.AA rating.

The Broof (t4) test measures:

  • How far flame spreads across the roof surface
  • Whether fire penetrates through the roofing system

A roof system that achieves Broof (t4) provides reassurance that it offers the highest level of resistance to external fire exposure.

EPDM Fire Performance

EPDM (Ethylene Propylene Diene Monomer) membranes have an excellent track record in fire safety:

Why Work With Holrow?

At Holrow, our focus is on helping the modular and construction industry achieve genuine compliance with fire regulations. While manufacturers may provide Broof (t4) certification for their membranes, we recognise that many modular roof build-ups differ from the tested specification — leaving buildings at risk of non-compliance.

✅ Key Takeaway: An EPDM membrane may carry a Broof (t4) certificate, but compliance depends on the entire roof build-up being tested and approved. Holrow ensures this gap is addressed, protecting both specifiers and building owners.