BS 476-7 Fire Test to Building Material – Standard Brief
This Part of BS 476 specifies a method of test for measuring the lateral spread of flame along the surface of a specimen of a product orientated in the vertical position under opposed flow conditions and a classification system based on the rate and extent of the spread of flame. It provides data suitable for comparing the end-use performances of essentially flat materials, composites or assemblies, which are used primarily as the exposed surfaces of walls or ceilings.
BS 476-7 Fire Test to Building Material – Test Method
a) Ignite the pilot flame.
b) Remove a specimen construction, including any backing boards, spacers and filler pieces, from the conditioning atmosphere, and within 5 min insert it into the specimen holder in its standby position at 90Ê or more from the test position.
c) Within 5 s swing the specimen holder and specimen into the test position, and immediately start the timing mechanism, i.e. start the test.
d) Extinguish the pilot flame 1 min after the start of the test.
e) Terminate the test when the flame front reaches the 825 mm reference line, or after 10 min has elapsed, whichever is the shorter.
f) Swing the specimen holder into its standby position and remove the remains of the specimen construction. Clean any debris from the holder.
g) Repeat the procedures given in a) to f) above for each of the remaining specimen constructions.