A high performance, microfiber reinforced, polymer modified, semi-pourable, thin set mortar especially formulated for horizontal, large format tile installations. Use for installing porcelain, glass, mosaic, quarry, ceramic and most natural stone tiles over interior or exterior concrete and masonry floor surfaces. Also, use for interior applications over exterior-grade plywood. May be used on floors with in-floor heating systems. Special additives virtually eliminate the risk of efflorescence. ARDEX X 78 MICROTEC® Fiber Reinforced, SemiPourable, Polymer Modified Thin Set Mortar is formulated to provide high bond strength and flexibility, making it ideal for the installation of large format tiles in high traffic areas. Its unique, semi-pourable consistency makes application over large areas fast and easy. Also, it provides excellent contact upon setting eliminating the need to back butter the tile in most instances.