The LWF Blog
Fire Safety for Facilities Management Personnel – Structural Fire Protection – Part 161August 1, 2022 11:25 am
Lawrence Webster Forrest (LWF) is a specialist fire engineering and fire risk management consultancy whose aim is to give information on best practice in fire safety for facilities management personnel through this blog series. In part 160, LWF discussed fire doors and considered what checks should be undertaken on a regular basis. In part 161, we look at protection against flame spread over linings.
Linings are those coverings which may be used to line walls and ceilings in a building. When such materials are present in an escape route, they should be chosen to ensure fire is unable to spread rapidly across the surface and that they will not release significant amounts of heat in a fire. Within a room not forming a part of the escape route, there are less stringent requirements in place.
In England and Wales, B2 of Schedule 1 of the Building Regulations states the following performance requirement:
(1) To inhibit the spread of fire within the building, the internal linings shall:
(a) Adequately resist the spread of flame over their surfaces;
(b) Have, if ignited, a rate of heat release which is reasonable in the circumstances.
(2) In this paragraph, ‘internal linings’ mean the materials lining any partition, wall, ceiling or other internal structure.
The performance of linings is tested in accordance with BS 476-7, in which materials are grouped into one of four classes indicating the rate at which flame travels over the surface of the material in a test.
A Class 1 lining will indicate it has the best performance (lowest flammability) whereas Class 4 will show the worst performance. Approved Document B permits Class 3 linings in very small rooms only, and specifies Class 1 linings are appropriate for use in other rooms (with very small areas of Class 3 in certain circumstances).
Approved Document B also states alternative European standards, as described in BS EN 13501 and which are based on a combination of European test standards.
In the case of circulation spaces, however, Approved Document B sets out an even higher provision for linings named Class 0. This class is a composite class existing only within the building regulations. A class 0 material is one which achieves class 1 when tested as per BS 46-7, but which will not release heat at a significant rate when the material is burning. The use of this material would help to ensure in that the contribution of linings to fire growth is minimal.
In part 162 of this series, LWF will discuss the protection against fire spread beyond the building. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact LWF on freephone 0800 410 1130.
Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 25 years’ experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.
While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.