Ultraflex 2 is a professional-grade, single-component, high-performance, polymer-modified thin-set mortar for interior and exterior installations of ceramic, porcelain and dimensional natural-stone tile. This mortar has a high content of unique dry polymer, resulting in excellent adhesion to the substrate and tile. Floors: Installation instructions for cement board on floors typically include applying cement-based thin-set between the exterior-grade plywood and cement board. The cement board is then screwed into the plywood while the thin-set is fresh/wet. MAPEI recommends the use of MAPEI's Ultraflex 1, MAPEI's Keraflex SG or MAPEI's Ultraflex LHT SG as Ultraflex LHT SG is designed for use at 3/32" to 1/2" (2.5 to 12 mm) thickness to give better support under large-format tile. This mortar is formulated with Easy Glide Technology™ for ease of application and good adhesion to the substrate and tile. Product Calculator Product documentation Ultraflex LFT Product Details. Mapei Ultraflex LFT White - Large Format Tile Mortar is a 50lb bag of premium, nonsag, large-and-heavy-tile mortar and thin-set mortar designed for large-format and heavy tile and stone for interior/exterior floor, wall and countertop installations. This mortar has a high content of unique dry polymer, resulting in excellent Ultraflex LFT White Mortar. MIXING Before product use, take appropriate safety precautions. consistency. For use with porcelain, ceramic, Saltillo tile, pavers and most types of marble, granite and natural stone. 2.1 into a clean mixing container, pour about 1.5 u.s. gals. Porcelain 50-lb Gray Thinset Tile Mortar.