Fire retardant coatings are used to bring building and construction materials into compliance with Federal, State and local building code requirements. The coatings must be fire tested and rated for their ability to retard ignition and flame spread. Both the coatings and the testing agency must be approved by building code officials.
Most fire retardant coatings work by suppressing flame through intumescence, which means they puff up on exposure to flame or excessive heat, solidifying into a foam. This foam insulates the substrate from the flame.
Fire retardant coatings reduce flame spread on the surface of a material. Fire retardant coatings are tested in a fire test chamber using ASTM Method E 84, "Standard Test Method for Surface Burning Characteristics of Building Materials." ASTM Method E 84 is used for testing of interior building materials, not those used on the exterior of buildings. This method requires that a 25 foot panel of the substrate coated with the fire retardant coating be exposed to flame for ten minutes. The retarding of flame spread and smoke development are measured, and the coating receives a flame spread rating equating to Class I, II, or III building materials.
Building Material Qualified by:
Class Flame Spread Index
IAG Fire Retardant Coating Product Data Sheet