| abstract |
FIRE BARRIER PLYWOODS ABSTRACT A fire resistant laminate resists flame spread and flame penetration therethrough. The laminate comprises (A) a solid, combustible lamina; and (B) bonded to the lamina (A), a hard, thin, continuous layer comprising an inorganic cementitious composition. Layer (B) is capable of maintaining its structural strength and dimensional stability with zero flame spread when exposed to a flame temperature of 2000°F for one hour. The inorganic cementitious composition in a fluid state is capable of adhesively bonding to wood and maintaining an adhesive bond to the wood after the fluid composition is dried to form the solid, thin layer. The inorganic cementitious composition consists essentially of (1) a mixture of two or more hydraulic setting or chemical setting inorganic cements, and (2) an activator. Each of the cements is capable of being set at a temperature to about 120°F within about 45 minutes by the activator. The resulting laminate has a fire retardant classification of Class I (or A). |