Schluter DITRA-DRAIN Membrane

There is no simple answer here. 1st thing to know is that all exterior schluter products (ditra drain) would only carry a 3 year warranty and all aspects of the project would need to be evaluated by a local Schluter rep to approve warranty. Aside from that everything would be a best recommendation, no warranty if you chose to bypass the exterior warranty process. Regarding the Coral Tile, it is best to aquire a data sheet from the manufacture as to what products they recommed for installation. They have most likey done some trial and error with multiple products to see what thin-set work best with their specific product. Please let us know how you would like to proceed and we get get you intouch with your local Schluter rep.