High Temperature Insulation Density 40 lb/cu ft Facing Material Unfaced Flexibility Not Applicable Foam Cell Type Closed Form Board Insulation Color White Insulation Material Calcium Silicate Maximum Operating Temperature 1 700 Degrees F Minimum Operating Temperature 0 Degrees F Overall Length 4 ft Overall Width 8 ft R Value 0.52 Thickness 1/2 in Standards ASTM C656 C795 E119 E136 E72 E84 NFPA251 UL 1479 UL 1709 UL 263 Water Vapor Absorption Minimal