So I bought a roll of the ditra membrane to lay ceramic tile over. I rolled it out and I am about 2 feet short of reaching the back wall with it. the area that it is not covering will be mostly covered by the vanity so I'm not too worried about that but will this affect how my tile sits if it goes from membrane down to concrete? The stuff is so thin I wasn't sure if it will make a difference. I really don't want to pick up another $100 roll for 6 square feet.

  • You can also double trowel. Meaning trowel the floor and also the back of the tile. – Joshua Brewer Apr 30 '19 at 3:53

Construction supply stores in my area just sell ditra by the linear foot (the MSRP is around $6/LF or $2/sqft for the 1m-wide version), so you can just go in and buy a small amount.

If you're relying on ditra for waterproofing it'll obviously be no good at that specific area. If moisture somehow goes through your grout and seeps under the ditra, it'll wick out through your plywood/subfloor anyway so it's not like it's sandwiched or anything. The height difference is easily addressed by using a taller trowel in the uncovered area, and for an area that small, I don't see it as enough to break everything else, even if it's grouted.

| improve this answer | |
  • Makes sense. I have a taller trowel I will try in that area. Thanks for the info sir – BigLake Apr 27 '19 at 0:28
  • A square/triangle notched trowel will compress down to approximately half its height as the ridges flood the valleys. If you used a 11/64" trowel to lay your 1/8" ditra and 1/4" trowel to lay your tile on the ditra, it'll add up to around 43/128" or 11/32" depth, which means you can get away with a 3/4" trowel angled slightly. – Steven Apr 29 '19 at 20:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.