Custom Building Prod 50 lb. Self-Leveling Floor Underlayment

The Custom Building Prod 50 lb. Self-Leveling Floor Underlayment is formulated for interior floor preparation prior to installing ceramic tile, natural stone, resilient flooring, carpet, wood, and parquet. It can be applied over concrete, WonderBoard, cement backer board, sheet vinyl, PVC, concrete terrazzo, and stone substrates. The formulation seeks its own level in minutes to create a smooth, flat surface. Engineered with controlled cure technology, this underlayment prevents installation issues such as bond failure, crumbling, mildew, and resilient flooring staining caused by free moisture. Built-in Moldguard technology actively resists mold and mildew growth. It is walkable within hours and meets ASTM standards for ceramic tile installations over wood subfloors.