AcrylPro Ceramic Tile Mastic, 1 gal. is a versatile, high-performance adhesive designed for installing ceramic tile, ceramic mosaic, and quarry tile. This white, non-staining mastic works effectively over a variety of surfaces including gypsum wallboard, exterior grade plywood, concrete, plaster, glass mesh mortar units, and even existing ceramic tile. It is i for use on interior floors and walls, and is especially suited for areas exposed to prolonged water contact such as tub enclosures, showers, and countertops. Please note that it is not for exterior applications. This nonflammable mastic reliable coverage, with one gallon typically covering about 21 square feet, though actual coverage may vary depending on the substrate, tile type, and trowel size. Model Number: