LARGE SCALE FIRE PROPAGATION TESTING addresses the risk of fire in exterior building cladding. Many countries have developed their own test methods. Through our partner, Tom Bell Wright, we do all relevant fire standards.
NFPA 285 consists of one room over another. There is a gas burner in the lower room to simulate a fire. The test specimen of the external cladding system, containing a window opening and instrumented with thermocouples, is constructed on a frame which is placed in front of the apparatus. The test duration is for 30 minutes and at the fifth minute another burner is placed in the window opening. It is designed to simulate a room fire which has burst out of a window.
BS 8414 and AS5113 have an 8m high, L-shaped structure with a large hearth representing a window opening. The specimen is built onto the structure (part 1 uses a concrete block base wall & part 2 uses a steel frame substructure). A large ‘crib’ of wood sticks is ignited in the hearth and the test is conducted also for 30 minutes. The test results are classified according to standard BRE 135.