Synthetic Guard™ Underlayment is a non-woven synthetic Underlayment with a black coated polypropylene spun bond fabric surface, a polypropylene scrim, and a black backside coating. Synthetic Guard can be used for wood Shake, Asphalt or composite Shingles. It also is intended as a secondary layer for shedding water after installation of the roof system. Used as a synthetic Underlayment to be applied over the deck prior to installation of the final roof covering.