Made from two layers of kraft paper laminated using a polymer, this new Floor & Tile Underlayment from Barricade contains no asphalt. According to the maker, the material helps prevent cupping and buckling of wood flooring by slowing vapor transmission without trapping moisture in the subfloor, letting flooring acclimate gradually. Available in 36- and 48-inch rolls for about 3 cents per square foot. barricadebp.com