In addition to the installation guide above, we also recommend using the Defender Series underylayment. It is designed and manufactured from a 2 mm Neoprene with a 3 mil vapor barrier. The Defender provides protection and sound reduction to your vinyl floor. It is resistant to growth of bacteria, mildew and mold. This underlayment is easy to install and goes over all sub-floors, including cement and plywood. Not only does the Defender series underlayment have a good thermal value, it also is an impact absorbent. The Defender meets the warranty requirements. Check out THE DEFENDER. The Defender is the official underlayment for Moroccan Coast Engineered Vinyl!