ARDEX X 4™ Tile and Stone Mortar Delivering high-performance and value for the everyday tile installation The ideal everyday tile and stone mortar delivering performance and value. An easy to mix and apply, polymer-modified mortar with good sag resistance and strength for use with porcelain, ceramic, quarry, mosaics and most natural stone tile over common interior surfaces, as well as horizontal exterior installations of porcelain tile over concrete or masonry surfaces. ARDEX X 4 is recommended for most common tile sizes. Interior and exterior use Working time: 15 to 20 minutes Open time: 10 to 15 minutes; Pot life: 3 hours 40lb. (18 kg) bags, Gray and White Coverage: 80 sq.ft. (7.4 m²) * For moisture sensitive and natural stone tiles use ARDEX X 32™MICROTEC® or ARDEX N 23™ MICROTEC® (interior only).