ABSTRACT
Generally the guidance given in Approved Document A1 is intended to apply to domestic buildings with exception of small, single-storey buildings for non-residential use. Approved Document A1/2 gives no guidance on the construction of external walls in non-residential buildings other than to refer to BS 5268: Structural use of timber. The selection of the materials to be used and their proportions in the mix of mortar are to match the bricks used, building loads anticipated and the degree of exposure of the building. The Building Regulation LI states that ‘Reasonable provision shall be made for the conservation of fuel and power in buildings by limiting the heat loss through the fabric of the building. The principle applied in the requirements for fire safety in external walls is that there should be sufficient fire resistance to prevent a spread of fire across the boundary. Wall surfaces and any cladding to a structural frame must, when facing a boundary, possess fire-resisting surfaces.
