Approval Standard FM 4471
As stated by FM, “The requirements of this standard shall be used to measure and describe the performance of Class 1 Panel roofs in response to exposure from heat, wind, foot traffic, and hail...”
Incorporated into the overall test procedure are tests to measure Combustibility from below Roof Assembly and Combustibility from above Roof Assembly.
When testing Combustibility from below Roof Assembly, the test criteria demands that the assembly shall not exhibit fuel contribution rates in excess of the test requirements, and also that “there shall be no dropping of flaming particles into the furnace or uncontrolled flaming on the surface of the sample.”
When testing Combustibility from above Roof Assembly, the minimum classification for receiving approval is Class (1) C; i.e.: the roof covering and substrate must be effective against a light test exposure, and “afford a light degree of fire protection to the roof deck.” The panel, its coating, and substrate shall not slip from position nor present a flying brand hazard.
During the tests there shall be no flaming or burning particles blown off the test assembly and reaching the floor. For combustible panels there shall also be no burn through the panel roof.