ARDEX FL Rapid Set, Flexible, Sanded Grout is a high-performance, Portland cement-based, polymer-modified grout that provides a smooth finish for floor and wall tile joints 1/16" to 1/2" (1.5 mm to 12.7 mm) wide on installations of porcelain, glass, quarry, ceramic, mosaic and most natural stone tiles. Freeze/thaw resistant, stain resistant, water repellent and naturally resistant to mold and mildew formation, ARDEX FL is also fast setting and can be open to traffic in just 90 minutes. With excellent flexibility and high strength, ARDEX FL is ideal for interior and exterior floor and wall applications, as well as for use in swimming pools and other wet areas with pH-balanced water.