Hi

Have Ditra under slate tile around a very old pool. Some tiles are loose so am having them put back down. Question has come if the Ditra is loose from the slab should we
1) take it up and go without the Ditra
2) take it up and put down new Ditra
3) take it up and thin set the old Ditra back down

Thank you

 

According to Schluter, Ditra is approved for exterior applications. However, you will need to access the shape of the bond between the ditra and the sub-structure to see if that is the reason for the slate failure or if something else. My guess is that the tiles have popped off from normal freeze/thaw cycles. One thing to note and look for is if the seams between sheets of Ditra have been waterproofed to prevent seepage of water under the ditra which brings that into the freeze/thaw stresses. Kerdi membrane would have been run along those seams to prevent that from happening.

 

tile is a freezing climate is always a no-no !