Underlayment selection is a pivotal part of any roof-replacement-metal-clay-roof/ process. For metal roofing, high-temperature self-adhering membranes are preferred because metal surfaces can reach extreme temperatures that melt standard asphalt felt. For clay tiles, a heavy-duty reinforced underlayment is necessary because tiles are not entirely waterproof; they act as a primary shed... https://kkroofspecialist.com.sg/roof-replacement-metal-clay-roof/