Ready to Use Skimcoat & Patch is a water-based product that is intended to repair minor imperfections to the substrate prior to the installation of the floor covering. It can be used to fill small voids (up to ¼" (6 mm) deep per application) such as knot holes, nail marks on the floor, nonmoving cracks, seams and joints. This product is designed to have floor covering installed on top of it and is not for use as a final wear layer. It is desgned for porous substrates only.