Fire resistance testing for tile roofs involves checking how the material responds to intermittent flame, spreading of flame and burning brand ignition. These three testing methods confer an ASTM E 108 rating of either A, B or C based on the performance of a tile assembly. .
The three classes are defined as:
- Class A fire rating – The best rating for roofing. It means that the material is able to withstand heavy exposure to fire from sources outside of the building.
- Class B fire rating – The roof material can withstand moderate fire exposure from source origins outside of the building.
- Class C fire rating – Roofing tiles or shingles rated C are only able to withstand very light exposure to fire sources originating from outside a building.