Uneven match between walls and Hardiboard in shower

Ocelot

I am installing white subway tile around my shower. Upon removing the old surround, I found the walls were drywall above where the surround ended. In some places the drywall was 1" thick (one layer on top of another layer). On the back wall it was 3 layers thick. I put up 1/2" OSB on the studs, then 1/2" Hardi 500 over the wood. The result is that on 2 walls (this is an alcove installation) the Hardi is level with the rest of the wall, however, on the third wall the Hardi sits in almost 1/2"

I was considering using mortar like joint compound, since Hardi recommends you fill in the gaps with mortar anyways. I would be applying the mortar and feathering it down in attempt to make everything even for tiling. Is this the best option, or is there something else I should be using for this?

JazMan

I'll assume this is the same bathroom you're planning to install marble tiles on the floor to.

1/2" OSB is probably not 1/2" thick if it's anything like plywood. You might have also noticed that Hardie 500 is not 1/2" thick either. I think it's something like .47 or may be less. If that one wall is 1/2" off from where you want it, go ahead and install another sheet of Hardie, I guess. Next time just use shims behind the boards as necessary.

Do not use any drywall compound, bad stuff for wet areas and also thinset hates it.

Did you install a vapor barrier on the studs, or you gonna go with a surface membrane of some type?

Jaz

__________________
Tile 4 You LLC Troy, MI
KERDI Shower Specialist ... DITRA Installs ... Product-Method suitability consultation. I have NEVER made a mistake, I thought I did once...........but I was wrong! - PRODUCTS ADVERTISED WITHIN MY POST ARE NOT ENDORSED BY ME!

Ocelot

Jaz, you have been a wealth of info, thank you. Yes this is the same bathroom. We are working on a total remodel. It is my intention to go with a surface membrane. My plumber advised me that plastic isn't used all that often anymore.

I'm trying to finish up the shower install before tackling the floor. My new whirlpool tub is in, and I'm planning on tiling the entire shower. I'm comfortable tiling, but only when I get my walls 100%. The ceiling is another tiling issue since its an arch. I plan on using smaller mosaic tile since it will take the curve better, but I obviously can't put any hardi on it.

Also, when I said use mortar like joint compound I meant use the ceramic mortar to level the surface, similar to how joint compound its used to hide joints.

JazMan

OK, surface membrane is the best way anyway. Showers are difficult to build correctly. What are your plans for the floor and curb area, how you gonna build those? What type on shower pan membrane, are you going with a traditional method membrane?

Got any progress pics? When you say "the whirlpool tub is in", do you mean installed or in your possession?

Jaz

__________________
Tile 4 You LLC Troy, MI
KERDI Shower Specialist ... DITRA Installs ... Product-Method suitability consultation. I have NEVER made a mistake, I thought I did once...........but I was wrong! - PRODUCTS ADVERTISED WITHIN MY POST ARE NOT ENDORSED BY ME!

Ocelot

The tub is installed. The plumber installed it for me. I don't think they installed a membrane. It was put in the alcove on 1x4 ledgers and the front was framed with 2x4s. I plan on using a nice veneered plywood for the front, capped with a trim piece. I will put plenty of poly on it to protect it. It has to be removable so I can access the pump. I will post some pics when I get off work.

Ocelot

Here are some pics of what I have so far.

JazMan

Ok, correction. A few posts ago I asked how you were building your shower cuz you said you were tiling a shower. So I thought you had a shower, that's a tub surround/enclosure, not a shower. I misunderstood.

Were you actually planning on using this tub to take showers? Looks to me like it's not the right kinda tub for that. That's a drop-in tub to be installed on a tub-deck for bathing and soaking, isn't it?

In the first pic showing the back wall, next time you should install the sheets on the back wall horizontally, or is that a 6' tub? The sheet on the right doesn't appear to be fastened near the center of the wall, is it?

Another pic, #0060, how the heck are you gonna tile over that? Pic #0062 appears to be the same from a different view. You need to do some work yet.

Jaz

__________________
Tile 4 You LLC Troy, MI
KERDI Shower Specialist ... DITRA Installs ... Product-Method suitability consultation. I have NEVER made a mistake, I thought I did once...........but I was wrong! - PRODUCTS ADVERTISED WITHIN MY POST ARE NOT ENDORSED BY ME!

Ocelot

I definitely have more work to do. The tub is a drop in, however, it can be installed in an alcove with the proper supports. An optional tiling flange could be bought, however, I think a good silicone seal will work.

I am not sure what to do with that wall in #060. I thought about using the thinset to fill the joint, then feather it out. The problem is the wall is inconsistent in its thickness.

JazMan

That is not why I don't think you should use it to take shower in. I think the outer edge, is curved the wrong way. Water will go towards the wall. It's not made for your purpose. You'll need a shower curtain on 3 sides. Been through this discussion before.

Jaz

__________________
Tile 4 You LLC Troy, MI
KERDI Shower Specialist ... DITRA Installs ... Product-Method suitability consultation. I have NEVER made a mistake, I thought I did once...........but I was wrong! - PRODUCTS ADVERTISED WITHIN MY POST ARE NOT ENDORSED BY ME!

Ocelot

I have since fixed the problems from the pictures and started tiling. So far, so good! I cut away some of the drywall above the hardi backer, as after I felt it with my hand I noticed it sloped inward. Once I cut this I installed another 1/4 " sheet of hardi, and it was flush. Then I taped and used thinset to smooth out the joints.

I used a waterproof membrane on the walls and ceiling, then tiled up to the ceiling. All I have left now is the ceiling. The plan is to put up random pattern mosaic tiles (the kind that come on 12" by 12" mesh). I am hoping I can use the same thinset (I have been using the high quality stuff with polymer additive for the ceramic tiles).

Will the mosaic tile stick on the ceiling with that stuff, even if it is too small to provide much suction (the mosaic is mainly marble with a few glass pieces)? My other concern is, because my ceiling is a curve, I cannot put any kind of cement backer on it. Do you think that the drywall will hold (given that the tiles are very small, 1/2" by 2" are the largest) or do you have any ideas for reinforcement?

Ocelot

I get what your saying. I did, however, tape plastic to the studs and tested out the shower before I began constructing the walls. It did not seem that the water ran towards the walls. Though I did silicone between the Hardi backer and the tub, and I will caulk the space between the tiles and the tub once the tiles are set, in order to keep the water out.

JazMan

Well, several things you did are not compliant, but it might work anyway.

The same modified thinset will work for your mosaics to the ceiling. Be sure to use a small notched trowel, gonna get messy anyway. Probably could have used something a little larger, (tile) but ok........

No need for concrete board on the ceiling, plus you said you applied some waterproofing. What kind, how many coats, mil thickness? Is the plastic still on the studs under the concrete backer with membrane on it? You also used 1/4" Hardie on the wall?

In summation, if the walls are flat and you applied a surface membrane and used a good thinset mortar, and you siliconed that gap between the Hardie and the tub and caulk between the tiles and tub, you should be good.

Jaz

__________________
Tile 4 You LLC Troy, MI
KERDI Shower Specialist ... DITRA Installs ... Product-Method suitability consultation. I have NEVER made a mistake, I thought I did once...........but I was wrong! - PRODUCTS ADVERTISED WITHIN MY POST ARE NOT ENDORSED BY ME!