GAF Premium Acrylic HydroStop® Top Coat is a professional grade, water-based, acrylic elastomeric coating that is part of the GAF Premium Acrylic HydroStop® Coating System. GAF Premium Acrylic HydroStop® Top Coat can be used over a variety of substrates to help provide protection against damage from exposure to UV and weather elements. Used in conjunction with GAF Premium Acrylic HydroStop® Base Coat and GAF Premium Fabric, it creates the GAF Premium Acrylic HydroStop® System, a liquid-applied membrane for recover, reroof and new roof applications.