[dgfit]

I have finished applying modified thinset to durock joints around my tub/shower. The Durock is about 1/4 inch from the tub flange. My mistake is that I did not caulk between the durock and the flange before I applied the thinset. I will be applying Aquadefense over this. Do I need to worry about not having caulked? I do have some pieces of kerdi membrane - I could use that to also cover the bottom edge. I also need to apply some more thinset in some places I misses.

Thank you!

 

[chandler48]

Your durock should have sat on top of the tub flange, and it requires no sealing at this point. Your tile will jump the gap from the durock to the to of the tile without problems. I am afraid you have created a "pooch" out that may not let the tile sit squarely against the durock wall.

 

[dgfit]

Your durock should have sat on top of the tub flange, and it requires no sealing at this point. Your tile will jump the gap from the durock to the to of the tile without problems. I am afraid you have created a "pooch" out that may not let the tile sit squarely against the durock wall.

The durock is not overlapping the flange. I can remove the thinset if needed. My main question is about waterproofing the gap.

 

[chandler48]

I'd remove it for a flush fit. There won't be any water wicking up an inch under your tile. Ideally your vapor barrier would run behind the durock and extend into the tub area. Then as you lay your tile, you trim the vapor barrier short of the tile extension. That way, should any moisture get past all the tile and durock (unlikely) it will run down the vapor barrier and into the tub, under the tile. You may want to seal the bottom of the tile against the tub, but I don't to allow for moisture extraction. As I said, water won't wick up behind your tile. There's nothing to wick to if you remove your thinset joint.

 

[huesmann]

The backer only needs to come no closer than 1/4" or so to the tub deck, or even a smidge higher than the tub flange. (My preference is for the backer to be physically disconnected from the tub.) Your tile should come within 1/4" or so of the tub deck, no matter where your backer is. It's the gap between the bottom of the tile and the deck that needs to be caulked, not the backer.

 

[dgfit]

The backer only needs to come no closer than 1/4" or so to the tub deck, or even a smidge higher than the tub flange. (My preference is for the backer to be physically disconnected from the tub.) Your tile should come within 1/4" or so of the tub deck, no matter where your backer is. It's the gap between the bottom of the tile and the deck that needs to be caulked, not the backer.

Thats the way I have it now - the backer board is about 1/4” from the flange and I applied thinset to the joint between backer board and tub. It sounds like not matter what, I want to remove that thinset.

 

[chandler48]

Yes, remove that thinset.