Section 3.4 Loadbearing Elements of Structure
Premature failure of the structure can be prevented by provision for loadbearing elements of structure to have a minimum standard of fire resistance, in terms of resistance to collapse or failure of loadbearing capacity. The purpose in providing the structure
with fire resistance is threefold:
(a) to protect the occupants;
(b) to protect fire fighters who may be engaged in search or rescue operations (though this is limited and is not intended to cover fire-fighting operations generally);
(c) to reduce the danger to people in the vicinity of the building who might be hurt by falling debris or by the impact of the collapsing structure on other buildings.
3.4.2 Fire Resistance Standard
Structural frames, beams, columns, loadbearing walls (internal and external), floor structures, should have at least the fire resistance given in Appendix A, Table A1. 3.4.3 Application of the Fire Resistance Standards for Loadbearing Elements (see Appendix
A, Tables A1 ) The measures set out in Appendix A include provisions to ensure that where one element of structure supports or gives stability to another element of structure, the supporting element has no less fire resistance than that required for
the other element. The measures also provide for elements of structure that are common to more than one building or compartment, to be constructed to the standard of the greater of the relevant provisions. Special provisions about fire resistance
of elements of structure in single storey buildings are also given, and there are concessions in respect of fire resistance of elements of structure in basements where at least one side of the basement is open at ground level. See "Application of
the fire resistance standard in Table A1" in Appendix A.
3.4.4 Exclusions from the Provisions for Elements of Structure
The following are excluded from the definition of elements of structure for the purposes of these provisions:
(a) a structure that only supports a roof, unless the roof performs the function of a floor, or as a means of escape (see S1) or is essential for the stability of an external wall which is required to have fire resistance (see S4);
(b) the lowest floor of the building.
3.4.5 Additional Provisions
Additional provisions are required if a loadbearing wall is also:
(a) Separating wall (this includes a wall common to two buildings) (see 3.5);
(b) a wall between a dwelling house and a domestic garage (par. 3.5.2);
(c) protecting a means of escape (see Appendix A : Table A1)
(d) an external wall (see S4, sub-section 4.4 and 4.5);