The biggest disadvantage of a rubber slate roofing is that it is flammable and therefore, highly prone to fire damage. However, when fire-retardant chemicals are added during the manufacturing of the rubber slate roofing tiles, they can get better fire ratings. In many areas, the class A fire rating is very essential for the shingles to get approved for your roofing. Unpleasant is also one of the main demerits of this roofing, which fades with time after the installation.