DuPont™ Styrofoam™ Brand Scoreboard Extruded Polystyrene (XPS) Foam Insulation* is an extruded polystyrene foam insulation board that is scored longitudinally on 16” and 24” centers, making it easy to size to commonly used widths, cut and install. It has excellent insulating characteristics, high resistance to water and water vapor, exceptional compressive strength and long-term durability.