Composite panels for building constructions

A building panel comprising a main body portion of a closed cell, generally smooth skinned styrene polymer foam material having a surface containing one or more regions having indentations therein, said surface having applied thereto a substantially continuous binder coating of a styrene-butadiene copolymer latex consisting essentially of a styrene-butadiene-1,3 copolymer having a styrene to butadiene weight ratio of about 30:70 to 70:30, and based on the weight of said copolymer, (a) from about 2 to about 10 percent of non-ionic surfactant, (b) from about 0.75 to 7.5 percent of anionic surfactant, at least about 15 percent of which is sodium alkyl sulfate in which the alkyl groups contain 9 to 17 carbon atoms, the sum of (a) and (b) not exceeding about 11 percent by weight of said copolymer and the weight ratio of (a) to (b) being within the range of about 0.7:1 to 10:1, and adhered to said binder coating a protective cementitious facing material, a portion of which is contained in said indentations, said facing material consisting essentially of an admixture of portland cement, mineral aggregate and from about 5 to about 25 percent based on the weight of said cement of a styrene-butadiene-1,3 copolymer having a styrene to butadiene weight ratio of about 30:70 to 70:30, water in amount of from about 25 to 65 percent based on the weight of said cement, and based on the weight of said copolymer, (a) from about 2 to about 10 percent of non-ionic surfactant, (b) from about 0.75 to 7.5 percent of anionic surfactant, at least about 15 percent of which is a sodium alkyl sulfate in which the alkyl group contains 9 to 17 carbon atoms, and (c) from about 0.1 to 5 percent of a polyorganosiloxane foam depressant based on the weight of active polyorganosiloxane, the sum of (a) and (b) not exceeding about 11 percent by weight of said copolymer and the weight ratio of (a) to (b) being within the range of about 0.7:1 to 10:1.