Economical formula with good bond strengths for most tile projects and is recommended for floor installations. Non-modified mortar is formulated of Portland cement, for interior and exterior use. Use to bond vitreous, semi-vitreous or absorptive tile, ceramic, mosaic, quarry, pavers, cement, porcelain, brick and mini-brick, precast Terrazzo, and natural stone to concrete substrates, masonry, gypsum wallboard, wonderboard, backer boards, exterior grade plywood, existing ceramic tile, asbestos-free vinyl flooring, and plastic laminates. Some applications may require using acrylic mortar Admix. Not recommended for use over hardwood, luan, plywood, parquet, particle board, cushion, sponge-back, or asbestos containing vinyl flooring, metal, fiberglass and OSB panels. Approximately 85 to 95 sq. ft. per 50 lb. when applied with a 1/4" x 1/4" notched trowel. Exceeds ANSIA118.1 and A118.4 specifications. Allow to cure for a minimum of 24 hours before grouting or light traffic. Clean up immedia