Sakrete B-1 Trowel Grade Leveler and Underlayment from Bonsal American is a polymer-modified, cement-based, high performance leveler used for interior applications to level and prepare areas for final flooring installations. Designed for a wide variety of surfaces including concrete, cementitious backer board, exterior grade plywood and embossed vinyl tile, once applied, B-1 may be covered with asphalt, tile, vinyl flooring, carpet and/or wood flooring. The fast setting B-1 has non-shrink and feather edge qualities and its high tensile and compressive strengths add reliability. Sakrete B-1 Trowel Grade Leveler is available in 25 lb. bags at leading building material retailers.