ASTM C578 Type VI, 40

Owens Corning™ FOAMULAR® extruded polystyrene (XPS) tapered roofing insulation products provide performance and value in low slope roofing systems and are designed to be used over structural roof decks. The use of FOAMULAR® tapered roof insulation provides a sustainable roofing solution, helping to prevent ponding and damaging ice buildup in winter, while in summer resisting the growth of fungus and vegetation.
Tapered Roofing