Research forest products technologist, Forest Products Laboratory, Madison, Wis.
Pages: 16 Published: Jan 1983
Currently used fire retardant coatings for wood products reduce flame spread; they are not designed specifically to provide fire resistance. Fire resistive coatings designed for steel and foam plastics generally are not recommended for wood. Small nonload-bearing fire resistance tests were conducted in this study to determine the fire resistance of eight commercially available fire retardant and fire resistive coatings when applied to a wood product.
Coated plywoods over a foam plastic substrate were tested in a small-scale vertical exposure furnace in accordance with ASTM Fire Tests of Building Construction and Materials (E 119-82). The results were the times for the temperature rise to reach an average value of 139°C (250°F) or a maximum value of 181°C (325°F) at the plywood/foam-plastic interface. Uncoated plywoods were tested as controls.
Fire retardant coatings improved the times for plywood specimens by up to 900 s, and fire resistive coatings showed a 240- to 2640-s improvement over uncoated plywood. Coatings significantly improved the fire resistance of a wood product. The fire resistance data reported in this paper should aid in future considerations of fire resistive coatings in wood construction.
fire resistant coatings, fire retardant coatings, fire resistance, fire tests, wood, plywood
Paper ID: STP31891S