ROBERTS Silicone Moisture Barrier Underlayment is designed to protect floors from moisture, without trapping it underneath the floor covering. It is made from 100 percent recycled contents that are environmentally safe, and a baked silicone coating that provides moisture impermeability under wood flooring. As a recycled product, it may have slight color variations that do not affect the quality of the product or its performance. Its smooth top surface allows to mark chalk lines and to slide the planks into position, making it easy to install. It meets the perm ratings recommendation by the National Wood Flooring Association (NWFA) for staple and nail-down installations of solid and engineered wood floors.