BROOF(t4) Roofing – Fire Safety

by Dina Vaisman | Sep 17, 2024 | Roofing Questions

Fire Safety Ratings

Fire safety is an important factor to consider when choosing the correct roofing membranes for any project. In this article, we will discuss fire risk assessments and BROOF(t4), which is a fire safety classification in the UK.

Since the Grenfell disaster occurred back in 2017, fire safety is being taken more seriously by the government and the construction industry. This is also especially a focus now that the inquiry report from the Grenfell disaster has been published.

In 2019, ‘Fire Safety-Approved Document B’ (AD B) was created by trade associations and the government outlining what is required for roofs to resist spread of flame. The document also outlines how to prevent spread of flame from one building to another.

Important updates were made in 2020 and again in 2022, so that the European Classification system in BS EN 13501-5 would become the go-to reference in the United Kingdom for external fire performance of roofs.

This classification has five different ratings, BROOF(t4), CROOF (t4), DROOF(t4), EROOF(t4), and FROOF(t4). These ratings indicate how resistant a roof is to fire. The (t4) represents that the ratings are for the UK. BROOF(t4) is the highest rating, whilst FROOF(t4) is the lowest. The highest rating means that the roofing membrane can be used anywhere on the roof. Roofing membranes are tested to see how they would resist fire and prevent it from spreading if something is burning, for example, if a burning tree branch was to fall onto the roof. Various scenarios and insulation thickness ranges are used for the tests.

Type 4 fire risk assessment is the most thorough. It is the main certification that is looked at for fire safety. First, one sample of the roofing system will be assessed. After that, a penetration test will take place using three samples. Joint details from every single layer of the roofing system will also be assessed in the penetration test. The rating will then be given according to the results.

BROOF(t4) rating means that fire penetration will be prevented for 60 minutes. Also, flame spread would be less than 0.38 metres across the area of burning.

The entire roofing system of a building needs to have a classification certificate in order to meet the Building Regulations for fire. This means that roofing materials within a system must not be swapped at a later stage with another material that has different properties, and a different fire safety rating. For example, sometimes a PIR board is swapped with another that has a lower rating. This could mean that the roof might not be able to perform as well as what it states on the roofing system fire certificate.

To conclude, it is important to consider the fire safety rating of roofing materials for any roofing project, to ensure that fire penetration and fire spreading is kept to a minimum.