Polyglass Polystick XFR is a dual-purpose fire-resistant and self-adhered waterproofing underlayment. The roof underlayment achieves a UL Class-A fire rating for combustible decks and is designed to withstand temperatures up to 265°F. The product features an SBS-modified-bitumen upper compound and a self-adhesive compound on the bottom with fiberglass reinforcement for strength and stability. Pricing varies by region. polyglass.us