A self-adhesive membrane composed of elastomeric bitumen (40 mils) and a trilaminate woven polyethylene. It is an air/vapor barrier used as an air/vapor barrier for door and window frames, brick ashing, roof ashing and other construction details. It is not recommended to use a product containing bitumen directly on softwood boards or flexible polyvinyl chloride. Surface preparation: Apply to a dry, clean surface free of oil, grease or residue. The use of a primer is recommended for dusty or porous surfaces. Use a sample to verify adhesion on the substrate prior to the installation. If superior adhesion is required, apply a coat of RESISTO H2O PRIMER or EXTERIOR PRIMER before installing the membrane.