Professional, extra smooth, large-and-heavy-tile mortar with polymer. Keraflex Plus is a highly versatile, non-sag/nonslump, large-and-heavy-tile mortar and thin-set mortar for tile and stone installations on floors, walls and countertops. This polymer-modified mortar is formulated with Easy Glide Technology™ for ease of application and offers excellent adhesion to substrates and tile. It can also be used as a mortar over uncoupling, crack-isolation, sound-reduction and waterproofing membranes.