Abstract: A method of manufacturing a water-resistant gypsum product including forming an aqueous mixture of gypsum, water and a wax mixture, wherein the wax mixture includes a hydrocarbon wax, and a substitute material selected from the group consisting of (a) an asphaltite, (b) a polyolefin homopolymer, (c) a polyolefin copolymer, and (d) combinations thereof; and forming the mixture into a structure, and drying the structure while permitting hydration of the gypsum to form a gypsum product.