Henry 640 VinylLock is a premium, high-performance flooring adhesive for the installation of vinyl-backed flooring, including solid vinyl tile, plank, and vinyl-backed sheet. Use as a pressure-sensitive or wet-set adhesive. Large format tile (greater than 16" x 16") must be installed using Henry 640 as a wet-set adhesive. Bonds to concrete, cementitious underlayments, suspended APA grade underlayment plywood, radiant heat subfloors where temperatures do not exceed 85 degrees, terrazzo, ceramic tile, metal, certain epoxy coatings, and fully adhered, noncushion-backed resilient on all grade levels. Can also be used over properly primed gypsum underlayments above grade only. Moisture and alkali-resistant, solvent-free and low odor, anti-microbial product protection, excellent plasticizer migration resistance. Trowel recommendation: Square-notch trowel (1/16" D. x 1/16" W. x 1/16" A.). Wet residue can be removed with a clean white cloth dampened with soapy water. Mineral spirits will remove dried adhesive residue.