CLASSIFIED EXTERNAL FIRE PERFORMANCE
Building Regulation Approved Document B (Fire Safety) roof classifications are to a European test system whereby whole roof constructions are measured for penetration and surface spread of flame. BROOF[t4] is the highest classification, FROOF[t4] is the lowest.
Transposition between the European test system and older national classifications can be seen in Table B2 in Approved Document B – Volumes 1 and 2. Regarding the highest classifications;
Where AC was previously the minimum level of external fire performance deemed acceptable, there were always specifiers who required improved fire performance and it should be appreciated that UK Building Regulations now seek this too, by means of:
