Bostik's TKO Urithane-based Hardwood Flooring Adhesive 4 Gallon BOSTIKS TKO is a one-part, trowel applied, moisture-cure urethane adhesive; this advanced scientifically formulated adhesive does NOT contain any water, has 0 solvent and 0 VOCs* as calculated per SCAQMD 1168. Once cured, TKO is waterproof and is not adversely affected by exposure to moisture or water; its superior properties provide a tough, flexible, tenacious bond to a variety of surfaces. TKO elastomeric characteristics allow the adhesive to move with the wood as it expands and contracts over the life of the floor. Easier to spread, holds better ridge, and cleans up easier than most moisture cure urethane wood flooring adhesives. Used to adhere all engineered, acrylic impregnated, solid plank-flat milled, shorts, bamboo and parquet hardwood flooring designed and recommended in writing by the hardwood flooring manufacturer for glue-down applications. This adhesive can be used to install plywood as described, as well as, ceramic tile, marble, and stone inlays for light commercial or residential applications. TKO may be used over all properly prepared substrates common to hardwood flooring installations including: concrete, plywood, particle or chip board (underlayment grade), well bonded vinyl and ceramic tile, cement backer patch/underlayments, radiant-heat flooring, and terrazzo. This product contains Bostik's BLOCKADE antimicrobial protection, which inhibits growth of bacteria, mold or mildew on the surface of the dried adhesive; the adhesive resists stains caused by mold.