ARDEX X 3 Tile and Stone Mortar is a Portland cement-based, polymer-modified mortar with good bond strength and sag resistance and a 3-hour pot life. ARDEX X 3 mixes to a creamy, easy to apply thin set mortar that is water and weather resistant. ARDEX X 3 can be used to install quarry, ceramic and most natural stone tiles on many common interior or exterior surfaces and also can be used for setting porcelain tile over interior, absorbent concrete and other cementitious surfaces. ARDEX X 3 is recommended for the installation of most tile sizes**, including mosaics, and is suitable for use over concrete floors with in-floor heating systems.