I'm doing a bathroom floor with cement coated foam backer boards and porcelain tiles on a chipboard floor. I've already got Mapei Mapeker Rapid Set Flex - which according to Mapei is a little flexible, but not much. I've also ordered a bag of Ultra Trade Rapid Set Flexible S2 Tile Adhesive from CTD - which being S2 is very flexible. I'm thinking the Mapei isn't as flexible as I'd want, so could I mix the two adhesives together to make an adhesive somewhere in the middle regarding flexibility? Does anyone do this?
