A thin set mortar that is fasting setting, premium multi-purpose, and polymer-modified. For interior or exterior installations, capable of setting all types of ceramic, porcelain, granite, slate, marble, limestone, and dimensional stone tiles. To be used over properly prepared concrete; structurally-sound, exterior grade plywood ( interior / dry use only ); cementious backer board; Bostik Ultra-Set Advanced, Bostik Black-Top, and Bostik GoldPlus; and existing, well-bonded vinyl composition tile ( VCT ) or ceramic tile.