- Design guides
- Flat roof design considerations
The design and construction of flat roofs needs to take into consideration resistance against fire outbreak on both the inside and the outside of the building.
Building Regulations set requirements that have to be met in order to provide a level of safety in fire for persons in and around buildings and also give guidance on how to achieve the required standard of safety. Guidance can also be sought from the Loss Prevention Council ‘Design Guide for the Fire Protection of Buildings’.
Resistance against fire on the outside of the roof is largely provided by the roofing system specified. Current UK Building Regulation Part B refers to a minimum designation of AC for a roof covering when tested in accordance with BS476 Part 3 (ENV 1187 test 4), if any part of the roof is within 6 metres of a relevant boundary.
The British Standard test classifies a roof covering in terms of its ability to resist penetration from an external fire and its ability to control flame spread over the surface. An explanation of the designation given above is as follows:
|A||Specimens not penetrated within 1 hour||Specimens with no spread of flame|
|B||Specimens penetrated in not less than half hour||Specimens with not more than 533mm spread of flame|
|C||Specimens penetrated in less than half hour||Specimens with more than 533mm spread of flame|
|D||Specimens penetrated in the preliminary flame test||Specimens which continue to burn for 5 minutes after the withdrawal of the test flame or spread more than 381mm in the preliminary test.|
All Bauder bituminous systems (except BauderTHERM Stripes) and synthetic Single Ply Systems have been tested to BS476 Part 3 and have achieved fire ratings that either meet or exceed Building Regulation requirements, please contact us for further information, call 0845 271 8800