Abstract: An improved lightweight cementitious product consisting essentially of an aqueous cementitious mixture and reclaimed polystyrene beads in which the reclaimed polystyrene beads are bonded to the cementitious material. The cementitious product is prepared by dispensing reclaimed polystyrene beads in an aqueous cementitious mixture, such as hydraulic cement and water, to form a resulting mixture, placing the resulting mixture in a mold, and compressing the resulting mixture in the mold until setting of the resulting composition occurs. The volume of the resulting mixture in the mold is reduced during compression by approximately fifteen percent of the original volume and substantially no water is exuded from the resulting mixture during compression. The reclaimed polystyrene beads are substantially spherical in configuration and have a particle size substantially larger than "virgin" polystyrene beads.