thinset adheres to sheet vinyl but not sealed concrete???
Several times a year this situation comes up with me. I need to tile over sealed concrete. The instructions for Custom Building Products' FlexBond thinset mortar say that it can be used over sheet vinyl products, VCT, and plastic laminate. They also say that concrete must accept water penetration to form a good bond and their reps told me that sealers need to be removed from it.
I don't understand why FlexBond will adhere to, for example, sheet vinyl which is smooth and won't accept water penetration, but not to sealed concrete. What's the difference?