BS476-3：建筑材料和构件的防火测试-屋顶外露部分防火测试
BS 476-3：Fire tests on building materials and structures. Classification and method of test for external fire exposure to roofs
Abstract 摘要
The tests described in this part of BS 476 are designed to give information about fires spreading to the roof of a building from a nearby fire outside the building itself. The tests are not concerned with the behaviour of a roof when subjected to the effects of fire on its underside. A preliminary test is made in which a specimen section of the roof is subjected to the effects of flame in the absence of radiation.
Unless the specimen is so affected by this test that it is obvious it would not pass the principal tests, i.e. the penetration and the spread of flame tests, these are then carried out using the radiated heat apparatus.BS 476-3:2004 describes the three stage test method incorporating burning brands, wind and supplementary radiant heat.
