Insulation is a vital component of a building’s envelope. For building designers requiring the highest quality rigid insulation, ThermalStar® Rigid Insulation provides unmatched quality, with a stable long term R-value that will last the lifetime of your structure. Manufactured under an industry leading quality control program monitored by UL and ICC-ES, ThermalStar Rigid Insulation meets or exceeds ASTM C578 standards, providing an HFC free, recyclable rigid insulation with a low Global Warming Potential (GWP).