Simulated stone, masonry, and brick textured products such as siding having a foam backing or with the hollow parts injected with foam or molded with foam in one or more steps, obtained when specially selected materials are properly admixed and formed via molding techniques. The foam backing is applied to the product in either a one or two step process. The foam backing may be used on panels, wall structures, and other products that may have contoured and textured surfaces and may simulate the appearance of conventional building and construction materials including, but not limited to, stone, brick, masonry, concrete, stucco, wood, other conventional building materials, and combinations of any of these materials are disclosed. The foam backing provides improves thermal insulation, improved sound reduction, improved rigidity, and improved dimensional stability. The disclosed invention is not limited to products in the building or construction industries and may be applied in the manufacture of a wide variety of products in other industries.