Keralastic is a premium-grade, high-performance, second-generation "flexible" acrylic latex admixture used to enhance the performance of Kerabond™ . This highly recommended admixture enhances bond strength, flexural strength, elongation and freeze/thaw durability. (See Kerabond/Keralastic™ System for complete attributes of this setting system.) To ensure proper flexibility, always use a latex additive when using a dry-set mortar for applications over plywood and for setting nonvitreous tiles. Keralastic meets or exceeds ANSI A118.4 and ANSI A118.11 requirements when mixed with Kerabond , Keraset ® or Keraflor™ .