For those times when you need an adhesive for exterior applications where freeze/thaw cycles and water are an issue. We carry a premium-grade dry-set mortar in both gray and white in 3# tubs for your convenience. Kerabond/Keralastic System is a high-performance, two-part system: Keralastic ™, a second-generation “flexible” acrylic latex additive, is used to enhance the performance of Kerabond ™, which is a premium-grade dry-set mortar. This system has exceptional bond strength, flexural strength, elongation and freeze/thaw durability. To ensure proper flexibility, always use a latex additive when applying a dry-set mortar over plywood or to set nonvitreous tiles