add 1/4" durock to existing 1/2" durock?

[newyork]

Hi All,

I just found out the person who installed the 1/2" durock above tub installed it almost flush with the flange, not in front of it as it should be so that the water will run off the tiles and not behind the durock. What can I do now? Can we install an additional 1/4 inch durock on top of that and then use a transition piece where it meets the drywall on the side walls? Luckily we plan using plain white field tile so I think I can find the large bullnose tile that would hide it. Any advice would be appreciated. I have been up all night worrying about this. Thanks in advance for any help you can give!!

[Bodie Powers]

Hello Maryann,

What type of waterproof system are you using for your tub surround?

[newyork]

Hi Brodie,

We have used a Lacrete or Laticrete blue paint on system on top of the durock we have now.

Thanks,
Mary-Ann

[Kman]

Would you be able to do a second coat on top of the 1/4" Durock? You'd be penetrating the existing layer with the fasteners.

Is this a tub with a shower?

When you say "almost flush", is it just proud of the flange, or behind it?

Can you post a picture of it?

[Bodie Powers]

Maryann, adding backer over the moisture barrier won't help in your situation since water will still wick through the added 1/4" CBU and end up running down the Laticrete moisture barrier.

Did the installer seal the gap between the tub flange and the bottom of the CBU with a silicone caulk? Doing so allow any moisture that finds it's way to the Laticrete barrier to drain into the tub and not onto the floor.

A picture or 2 would help.

[newyork]

Hi,

Kman- the durock is sitting on top of it but not completely, I can see the top of the flange looking down with some area of flange not covered by the durock completely. My understanding is that it should be sitting in front of it or proud of it. I don't have pictures right now. We would waterproof again.

Brodie- No, I am sure he did not put any caulk behind or on top of it the flange or behind
or under the durock. I can see what you mean about the water penetrating/wicking despite a new layer of durock. I will try to get pictures tomorrow.

Thanks you guys!

[newyork]

Kman,

I forgot to say it is a tub with shower.

Thanks,

Mary-Ann

[Bodie Powers]

Originally Posted by Mary-Ann

I have been up all night worrying about this.

Not to worry, the pro's here are expert problem solvers and will guide you through to a positive outcome.

[newyork]

Hi Bodie,

I really appreciate your help. I actually slept last night so I feel much better!
I was thinking it might be possible to cut out the existing durock about a foot or so above the flange and put in some kind of rubber or plastic to run behind that piece(acting as a sort of flashing) that I am replacing and seal also at the bottom with some type of sealant and then reapply the waterproofing paint on membrane to that new 1/2 inch x 12 inch or so durock section. I would of course also tape and thinset that piece before waterproofing it. After that I am thinking I might be able to then add the additional 1/4 inch layer of durock so that it will be proud of the flange, and start waterproofing the surface again. I was wondering if this would be considered a double moisture barrier and cause an additional problem.
Thanks,

Mary-Ann


th

[Richard Tunison]

Pictures would help a great deal with your situation.