A flooring membrane is a material used to provide a waterproof and moisture-resistant barrier between the subfloor and the flooring material installed on top. It is commonly used in high-moisture areas such as basements, bathrooms, and kitchens to prevent water damage and mold growth, as well as reduce sound transmission between floors. Flooring membranes can be made from polyethylene, PVC, rubber, or incorporate insulation. Proper installation and sealing around edges and penetrations are important for maximum effectiveness.