Henry 3 ft. W X 33.3 ft. L Fiberglass Self-Adhesive Shingle Underlayment 15 lb Blue

Waterproofing underlayment. Composed of a high tack rubberized asphalt, coated on a non-woven glass fiber mat. Lower surface has a split-release silicone release backing for ease of application. Specifically designed to provide secondary waterproofing protection to shingles as well as prevent ice damage and wind driven rain. Meets ASTM D1970-08 standard and is ICC listed. Self-sealing when penetrated by mechanical fasteners or roofing nails. Fully adhered system prevents lateral moisture migration