Products / AEP Span Underlayment HT

AEP Span Underlayment HT is a self-adhered, peel-and-stick SBS-modified rubberized asphalt roof underlayment with a white polyolefin composite film surface carrying an anti-skid coating, rated for temperatures up to 250°F and intended for use under steel and aluminum metal roofing, and also with copper and zinc roofing. It is 40 mils thick and is sold in 36-inch by 66-foot rolls (198 sq ft), with a 1/4:12 minimum slope recommendation and a 180-day UV exposure rating. The product sheet states it meets ASTM D1970, is UL Classified and covered by ICC-ES ESR-2206, and is acceptable for use in ASTM E108/UL 790 Class A rated assemblies, while noting it does not by itself make a metal roof Class A. AEP Span states the underlayment is required for all of its Full System Weathertightness Limited Warranties.