TRI-BUILT® High Temperature Metal Roof Underlayment is an advanced roof underlayment and leak barrier for use under metal, tile, shingle and slate roofing systems. High Temperature Metal is manufactured using high melt rubberized bitumen and a laminated polypropylene surface. These ingredients are designed for hot climates and for use under high heat conditions. TRI-BUILT® High Temperature Metal underlayment is specifically designed to resist heat up to 260 °F providing a strong and durable heat resistant underlayment.