GacoFlex U91 is a single-component moisture-cure polyurethane coating. GacoFlex U91 is a liquid-applied waterproof coating with diverse applications. Use this single-component, aromatic waterproofing membrane over metal, asphalt, and single-ply roofing systems, or over plywood and concrete as part of pedestrian and vehicular decking systems. GacoFlex U91 may also be used in shower pan liner applications. GacoFlex U91 is the ideal urethane coating solution for rejuvenating existing roofs or protecting traffic surfaces that require high durability and impact resistance.