Polymer-Modified Mortar Ultraflex 1 is a single-component, polymer-modified, thin-set mortar for interior and exterior installations of dimensional stone, ceramic, porcelain and quarry tile. This mortar has an above-average content of a unique dry p olymer, resulting in good adhesion to the substrate and tile. Ultraflex 1 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 ins tallations and exterior floors. For exterior commercial wall applications, we recommend using either the Kerabond/Keralastic™ or Granirapid® systems. Ultraflex 1 meets or exceeds ANSI A118.4 and ANSI A118.11 requirements when mixed with water.