Pre-Mixed Ceramic Tile Thin Set Mortar Gray, This No Mix, No Mess Alternative To Traditional Thin Set Mortars Spreads Quickly & Easily, Bonds Ceramic Tile Up To 18" x 18", For Interior Wall & Floor Installations, Protected By Moldgard Technology, Exceeds Ansi A136.1 Type I. Mortar Ready to use Pre-mixed, no mixing required Thin set Bonds ceramic floor and wall tile No mess Just spread and set For interior wall and floor installations Suitable for wet areas such as tub surrounds and shower walls Works great on concrete, masonry, plaster, drywall, backerboards such as Wonder Board and Easy Board, exterior grade gypsum wallboard in dry areas, and existing ceramic tile, and vinyl flooring Do not use on shower floors or areas exposed to prolonged water exposure or stream 1 quart.