APPENDIX A
CURRENT LEGISLATION ON FIRE PERFORMANCE (PART B) The movement of the structure in a fire state should be considered when detailing. The following extract is from Section B3 Approved Document B Volume 1 Dwellings (Clause 8.24 in Approved Document B Volume 2 Dwellings). 7.14 Compartment walls should be able to accommodate deflection of the floor when exposed to fire by either of the following means: a. Between the wall and floor, provide a head detail that is capable of maintaining its integrity while deforming. b. Design the wall so that it maintains its integrity by resisting the additional vertical load from the floor above. Where compartment walls are located within the middle half of a floor between vertical supports, the deflection may be assumed to The structural engineer should consider the limiting temperature of the structural steel to ensure the structural steelwork does not move excessively, and beyond the capability of the through-wall, in the event of a fire. be 40mm unless a smaller value can be justified by assessment. Outside this area, the limit can be reduced linearly to zero at the supports. For steel beams that do not have the required fire resistance, reference should be made to SCI Publication P288.
Regulation 7(2) and requirement B4 Materials 10.9 Regulation 7(1)(a) requires that materials used in building work are appropriate for the circumstances in which they are used. Regulation 7(2) sets requirements in respect of external walls and specified attachments in relevant buildings. NOTE : Guidance on regulation 7(1) can be found in Approved Document 7. 10.10 Regulation 7(2) applies to any building with a storey at least 18m above ground level (as measured in accordance with Diagram D6 in Appendix D) and which contains one or more dwellings; an institution; or a room for residential purposes
(excluding any room in a hostel, hotel or a boarding house). It requires that all materials which become part of an external wall or specified attachment achieve class A2-S1, d0 or class A1, other than those exempted by regulation 7(3). NOTE: The above includes student accomodation, care homes, sheltered housing, hospital and dormitories in boarding schools. See regulation 7(4) for the definition of relevant buildings. NOTE: The requirement in regulation 7(2) is limited to materials achieveing class A2-s1, d) or class A1.
Extract from Approved Document B Requirement B4
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