Products / Atlas ThermalStar E

Molded expanded polystyrene (EPS) rigid insulation made by Atlas Molded Products, a division of Atlas Roofing Corporation, listed on its roof insulation page for flat-sheet, tapered and flute-fill roof profiles. Offered in 10, 13, 15 and 25 psi compressive strengths (ASTM C578 Type I, VIII, II and IX); flat 4 ft x 8 ft sheets in standard sizes up to 4 inches thick with custom thicknesses up to 24 inches, and tapered 4 ft x 4 ft and 4 ft x 8 ft panels from 1/2 inch to 24 inches thick. The data sheet lists R-values per inch at 75 F of 3.9 to 4.4 and cites UL ER16529-01 and ICC-ES ESR-1962. The flat and tapered roof sell sheet states it is approved for direct-to-steel-deck use, is classified under UL 1256, and is eligible for Class A roof assemblies per UL 790; Atlas backs it with a limited lifetime warranty for physical and thermal performance.