Ultraflex RS is a premium-grade, single-component, high-performance, polymer-modified rapid-setting thin-set mortar for interior and exterior installations of tile. This mortar has a high content of unique dry polymer, resulting in excellent adhesion to the substrate and tile. Ultraflex RS is a FastTrack Ready™ product, allowing grouting in 2 to 3 hours. It can be used for both interior and exterior installations of tile in most residential floor and wall applications. In commercial applications, use on interior floor and wall installations and exterior floors. Thanks to MAPEI’s High-Hydrated Cement Technology (HCT™), Ultraflex RS offers superior drying-out characteristics for quick curing and does not contribute to efflorescence. Ultraflex RS meets or exceeds ANSI A118.4F, ANSI A118.11 and ANSI A118.15F requirements for fast-setting mortars when mixed with water.