Fire Safety Science Digital Archive

The use of wall boards has increased since the war, because of their many advantages over more traditional interior linings for walls and ceilings. The main types can be, roughly classified as combustible or incombustible. Fibre building boards comprise the bulk of the combustible boards others being compressed straw slabs and chipboard. Of the incombustible or near incombustible, plaster board is most widely used, other types including asbestos insulating boards and wood wool slabs. It was realised that the introduction of large areas of combustible material as linings to buildings might increase the fire hazard and in order to classify surface finishes according to the fire risk associated with them a test was added to B.S. 476 in 1946 which has formed the basis of a number of recommendations. The test had to be introduced at relatively short notice to meet an urgent post war requirement, and its basis was essentially arbitrary. A critical examination of the test has recently been made and it has become necessary to follow this by an examination of the effects of its application, to ensure that these are neither dangerously lax nor too restrictive. Since a high resistance to spread of flame is only one of a number of desirable properties, to put it in its proper perspective it is necessary to examine the other properties of different boards before going on to consider their uses. These are the possibility of dry process, and the large size sheets which can-be easily fixed, good thermal insulation, sound absorption, resistance to moisture, structural strength, low fire hazard and low cost. Different types of board possess these attributes to different degrees and the choice of a board will therefore depend on which of these properties are desired and if the properties are not inherent in the board whether they can be easily achieved by treatment.