Products / Polyglass Polytherm HD

Polytherm HD is a high-density polyisocyanurate cover board with a 4 pcf core and a coated glass facer on both sides, designed for use as a roof cover board. The 1/2 in board has an R-value of 2.5 per ASTM C518, and a 5/8 in board is offered in western regions only, in 4 ft by 4 ft and 4 ft by 8 ft sizes. It can be installed with approved fasteners and plates or with cold-applied and low-rise adhesives. The data sheet lists ASTM C1289 Type II Class 4 Grade 1 (109 psi), and its product disclaimer warrants against manufacturing defects that directly result in leakage for 1 year.