STYROFOAM™ HIGHLOAD Extruded Polystyrene Foam Insulation is a closed-cell foam insulation. STYROFOAM™ HIGHLOAD insulation features exceptional moisture resistance and R-value retention. All three STYROFOAM™ HIGHLOAD insulation products resist compressive creep and fatigue, delivering long-term compressive strength. Like all STYROFOAM™ insulation products, STYROFOAM™ HIGHLOAD are durable, versatile and reusable making them a preferred choice for a variety of high-load applications.