RESIDENTIAL USE OF SECOND UNDERLAYMENT UNDERNEATH HARDSURFACE PRODUCTS WITH ATTACHED UNDERLAYMENT

A second underlayment is allowed under any currently sold Shaw/Coretec Product with attached underlayment in a residential application. IIC (ASTM E492-09) and STC (ASTM E90-09) lab testing on certain Shaw/Coretec products tested with and without a second layer of underlayment, to date, does not indicate that a second underlayment will provide additional acoustic benefit. When used the second underlayment must be a maximum of 3 mm thick and have a minimum density of 190 kg/m3 or 11.7 lb/ft3.

The additional underlayment when used must be fully adhered to the subfloor with the appropriate adhesive. The subfloor must meet all requirements of being clean, flat, dry and structurally sound prior to installation of underlayment and flooring.

Below is a list of platforms that secondary underlayment is not approved for:

• Laminates (with attached pad)
• Floorte Hardwood
• Coretec Wood products
• Grouted LVP/LVT
• Pet Perfect (formerly Floorte Elite)
• Coretec Scratchless
• Resilient vinyl with attached Soft Step underlayment