APOC Weather-Armor® HT³ is a state of the art, premium roof underlayment and leak barrier for use under metal, tile, shingle and slate roofing systems. Weather-Armor® HT³' is manufactured using high melt bitumen, a high performance cross-laminated polypropylene surface and highly flexible rubber polymers. These ingredients optimize performance in hot climates and under high heat conditions. HT⊃ is specifically designed to resist heat up to 265 °F. Weather-Armor HT³ also utilizes Tri-Bond's® patented 3 component adhesive system. HT³ is the strongest and most durable underlayment in its class and provides an ideal substrate when installing metal, tile, shingle, slate and other roof systems. This high performance waterproof membrane helps keep your home dry providing a cleaner and healthier indoor environment to live in.