Texrite 31513 Total Flex Gray Tile Mortar 50 lbs - Texrite Total Flex is an extremely flexible, enhanced large and heavy tile mortar. It is composed of Portland cement, sand and special additives and is used as a bond coat for setting thick marble, granite, and other large and massive tiles like thin porcelain panels over a variety of substrates. Texrite Total Flex o­ffers the ease of application and economy of dry-set mortars while significantly improving bond strength, freeze-thaw stability, flexibility and other qualities.