GAF’s EnergyGuard™ HD PLUS is a half-inch thick, high-density polyiso cover board. It has an R-value of 2.5, and at 13 pounds per 4x8 foot board is a fraction of the weight of gypsum cover boards. With more than 110 psi compressive strength and a durable, coated glass facer, it is an ideal board for protecting a roof against the elements. This versatile product is compatible with mechanically attached TPO, fully adhered TPO, cold-applied MB, cold-applied BUR applications and more. For more information, visit