Get Nrdly Free Trial Built with Nrdly

DIY Bathroom Remodeling Part 2 : How to Fix Shower Walls

Learning how to fix shower walls is important.

Yet unfortunately a lot of folks ignore shower wall framing.

Remember this – tile work begins with plumb and even stud walls.

If the backer board is placed on top of uneven studs, the tile will also look uneven.

Thisย is probably the most important step in any bathtub tile installation.

And even if you’re hiring a contractor you’ll want to understand how it should be properly done.

Let’s dive in.


Bathtubs Lips and Why They Matter

In the last tutorial, I shared how we installed an Americast bathtub.

And this involved securing the tub to studs by using roofing nails.

The tub lip sticks out from the stud by about 3/16 of an inch and the nail head increases this depth even more.

If you install cement board over the lip/nail head, it will flare out at an angle.

Then the tile on the bottom portion of the tub will be flared out as well, i.e. it won’t be plumb or straight up and down.

This will also cause your tiles to angle outward, which looks really bad – especially in the corners.

I don’t want you to deal with this kind of headache and that’s why I’m sharing these tips.

You could add the backer board above the bathtub flange. I’ve done that with KERDI-BOARD

install kerdi board

This is a definite possibility if your backer board is plumb and the tile can go down to the tub deck while remaining plumb.

The proper way to waterproof the tub flange is with KERDI-BAND or some other banding product.

I add thin-set to the backer board and apply KERDI-FIX to the flange.

how to use mortar with kerdi board

And then I immediately embed one piece of banding.

kerdi band with kerdi board

I definitely recommend adding painter’s tape or Frog Tape to the tub deck. That way, the KERDI-FIX won’t get on it.

Also, you can use denatured alcohol to clean KERDI-FIX off tools. But this has to be done within 10 minutes of exposure.

If you’re interested in using KERDI-BOARD for a tub project here’s a great tutorial.

But if you need to fix your studs, I have some great fixes for that.

How to Fix Recessed Shower Stud Walls

There are two common problems with shower stud walls:

  • Recessed studs – bowing inward
  • Proud studs – bowing outward

Fortunately, the solutions are fairly simple.

First, in our situation, the studs were all even.

But they were all recessed in relation to the tub lip.

So we added furring strips.

Rob and I added lath to all the studs in the tub recess.

The lath is about 1/4 of an inch in depth and comes in 8-foot sections.

The cost for a bundle of 8 is roughly $2.99 – it’s cheaper than a box of Cheerios!

You can attach the lath to the studs using small 1-inch galvanized screws.

Lath can also be cut to size from plywood. This is a great solution if your tub doesn’t reach a knee wall or plumbing wall that has an outside corner.

Here’s a short video that shows some additional tips

What can you do if only one stud is bowed inward?

That’s actually super easy to fix – sister a new stud to it or wet shim (if your backer board can be wet shimmed).

By sister, I just mean screw or nail a new stud to the old one. And ensure the new stud is even with the rest of the studs.

Wet shimming is awesome because it involves applying thin-set mortar to the stud. This bumps out the stud and the backer board will rest on the mortar.

Here’s a quick tutorial that shows wet shimming in action

How to Fixed Bowed Stud Walls

The second problem is proud studs – this is when studs bow outward.

One easy fix for this is to remove the stud and replace it with a new one.

I use either a reciprocating saw with a 6-inch Milwaukee AX blade or an oscillating multi-tool to cut the nails holding the stud in place.

Normally there are two nails at the top and bottom of the stud.

That said, another option is to plane the bowed-out stud.

An electric planer is great for this. Here’s a short tutorial showing how it’s done

Here’s the bottom line,

Your stud walls have to be even, plumb, and 16 inches on-center for most 1/2-inch backer boards.

I highly recommend placing a level on every stud to see if they’re plumb.

Then place the same level across the studs and see if they’re in the same place from bottom to top.

This will allow your backer board and new tile to be set properly

What’s Next

The next step in this great bathroom adventure has to do with picking the correct backer board for your tiles.

I’ll share this info in my next post along with what type of material to choose for the surrounding walls in your bathroom.

If you’re doing a bathroom remodel and need help, join our Platinum Membership. I promise the step-by-step tutorials and Personal Coaching will make your life a lot easier.

Tap the button below to learn more



Bathtub Tile Prep

  1. Dave says:

    I think you could also bring the cement board flush with the lip (roughly) and then just tile over the lip, putting some thinset on it. tile should hold, right? That’s what I’ll be doing…would there be a serious problem with that?

    1. Dave, I’ve heard of people doing this as well and don’t see any issue with it. Especially if your bathtub lip isn’t that tall, say 1/2 inch or less. If you press the thinset into the void between the cement board and tub, tile over it, then caulk the transition between the tub/tile you should be fine.

      What kind of tile are you using? Are you doing any glass accents? Tiling can be a pain but the reward is the bragging right


  2. Andy says:

    I have a bare brick wall on the opposite side of the faucet. The length from stud to wall is 62.5 inches but the studs are not perfectly flush nor is the wall any tips?


    1. Hey Andy,

      Can you send some pictures to me at [email protected]? I’d like to see your situation so that I can give you a good recommendation versus a shot in the dark ๐Ÿ™‚

      Thanks friend.


  3. Mae says:

    Hi Jeff, can we get an update on Andy’s situation (crooked walls and studs off)… as I am in the same boat (drywall is up already yet the tub is not flush to the studs – rather, to the drywall itself! yikes)..

    I would love to hear of a solution/how to handle this. Thank you so much.

    1. Hi Mae,

      I’ll reach out to Andy and ask how he handled his situation. Is your problem that the tub lip is not flush with the studs?


  4. Cathie says:

    Hi there.. Can I just use regular finishing nails to temporarily secure the lath strips to the studs? Aren’t the hardie backer screws going to hold them securely in place? Thanks in advance.

    1. Hey Cathie, you can use finishing nails or a brad nailer. The brad nailer would be quicker and you’re totally right that the cement board screws will be holding them in place anyway. Sounds like you’ve got a good project going on. Make sure to keep me posted. And as always, I love seeing before and after pics. So send them to jeff@homerepairtutor along with some tips that you’d like to share ๐Ÿ™‚

  5. Cathie says:

    OK one more question.. the lath that you bought seems perfect, the bundle I bought at hd is all messed up looking/uneven/split and there’s some pieces that looked like they had some mold on it.. Where did you get yours?

    1. Cathie says:

      Arrghh.. also, are all the studs supposed to be absolutely even as in no gap whatsever when hold a straight edge across them? I have a few that are about 1/8 pushed back.. Is this OK or too much of a gap? Thanks again for answering.

      1. It’s preferable for the studs to all be even otherwise the tile will have lippage and not look great in some areas. You can fix this by sistering 2x4s to the existing studs, i.e. simply attaching new studs to the old ones such that the new studs are 1/8 inch farther out.

        Attach the new studs to the old ones using 2 1/2 inch or 3 inch decking screws. Having two people for this job would be preferable so that one person could attach the new stud while the other ensures it’s even and plumb.

    2. It was replacement lattice from Lowe’s or HD. It comes in long sections that you can trim down to the appropriate size. You should be able to find it in the lumber section near the actual lattice fencing. Hope this helps and let me know if you have any other questions ๐Ÿ˜‰

      Can’t wait to see your final product.

  6. Mae says:

    Hi Jeff, sorry for the delayed response. Our contractor has completed the job. The issue was that the tub was not installed right to the studs, rather it was installed after the drywall was put in… so it was touching (also however it had some spaces in some areas) up to the drywall. The contractor installed the flange and provided a good seal over it, and all the way up the walls with this glue like waterproof compound (apparently what they use outdoors so nothing will penetrate). We are very happy with the final job considering the original contractor messed it up for us.

    1. Good to hear Mae, bathrooms can be tricky and I’m so sorry that you had a bad contractor the first time around. That just stinks.

      But now you’ve got a wonderful new setup that you’ll love for years to come.

  7. Cathie says:

    Jeff would you happen to have any other pics of the bathroom that has the beige 12×24 tile? We’re using the same size tile and not sure how to tile the short walls(showerhead wall and back of tub wall). Thanks.

    1. Hi Cathie,

      Are you staggering the tiles like in that photo or are they going to be in a stacked configuration?


  8. Cathie says:

    Jeff, may I ask why you didn’t center the larger tiles? For example the bottom row right above the tub (12×24 tile pic) the middle tile is off center and to the right. Can you explain why you did this rather than centering it and having two equal size pieces on each side? Thanks!

    1. I think you’re referring to a different project Cathie. It’s the one where the tile is 12 x 24 and white or off white in color, right?

      I chose to stagger the tiles because I liked the look and it matched the front & back walls of the tub. If I had made two equal cuts for the front/back walls the project wouldn’t have really fit the design I wanted.

      Thanks for your question. It really brings up the options you have when tiling. And it shows that you can use your imagination to create a cool space.

  9. michael says:

    Jeff, what if the front of my tub (the side with the faucets\drain) is 7/8in away from the studs and the other two sides of the tub are flush with the studs. How to I shim the studs at the front of the tub and ensure that the cement board does extent out over the drywall above?

    1. Michael, do you mind sending me a few pictures of the tub so that I can see what you’re dealing with. Send them to [email protected]

  10. Michelle says:

    Hi Jeff

    Can you please share some more pics (or email me)of the tiled shower with the 12X24 tiles. I plan to use the same size tile and would like another example or two to show my contractor.

    Thank you

    1. Thanks Michelle for asking. You might like this tutorial since it has pictures of a 12×24 tiles

      Although I will say this, the tiles in that tutorial are clay based and any crack or chip is very noticeable. We recommend getting porcelain tiles that are the same color throughout. Hope that helps.

  11. David H. says:

    Hi, Jeff,
    I’m remodeling my bathroom and the tub has a 1/4″ gap between the lip and the wall at the back end. I’m planning to panel the entire wall with an extremely thin panel and then fit a five piece surround as well for a more “finished” look. How should I deal with the 1/4″ gap? Shims?

    1. I’ve used shims David with good success.

      You can also use replacement lattice pieces, the kind used for exterior fences. They work great for this shimming project because they can be tacked to the studs using a brad nailer or roofing nails.

  12. Katherine says:

    I am new to this site, and to every other like it. I have read many of the forums and comments following and have been able to learn a lot from doing so which is greatly appreciated, but I do have a few questions as all the terms and lingo are new to me. reading this particular forum I am wondering if you could tell me what exactly it means to make sure that the “tub is flush with the walls”… I am just about done taking down the walls around my tub, and want to make sure that I prep the area right before putting up the backer board…

    Thank you for any help…

    1. Thanks Katherine for asking. ‘Flush’ simply means that the tub lip should be up against the 2x4s. That way the tub lip can be properly secured to the stud wall. This tutorial is good but we made another one that is a lot better. It has a ton of details and a great step-by-step video.

      Here’s the link to our other Americast tutorial

  13. Sabrina says:

    Hi Jeff,

    If I attach 1/4″ laths to the studs, when I attach the cement board won’t it jut out 1/4″ instead of aligning flush with the existing drywall? How did you address that in your remodel?

    1. For this remodel the existing drywall had a 1/8 inch plaster coating over it. So we had to feather the new cement board to the old drywall/plaster using setting type joint compound.

      Not a big deal, just took some extra time. Hope that helps Sabrina.

  14. Tim says:

    Hey Jeff,

    Great read on here. I have a question for you. The studs on the widest part of the wall are flush with the lip but the other 2 walls have studs that are about a quarter of an inch over the lip. This is due to a drain from the laundry room hooked up to the bathroom drain since both rooms are next to each other. When I lay the cement board there will be a gap behind the cement board since the studs go over the lip of those 2 walls. Should I fill that space in between the back of the cement board and lip with silicone? Also since the stud are going over the lips on the 2 walls should I try to go as low as possible when I lay the cement board without the cement board touching the tub?

    1. Actually you’re not in a bad situation Tim.

      I’d use silicone to fill the gap between the studs and tub deck.

      I would try to make the cement board be about 1/4 above the tub deck. Then fill the gap between the cement board and tub with silicone.

      You should be in good shape.

      Keep me posted.

      1. Tim says:

        Ok so far so good. Thanks for the tips! Should I start laying my tile only on the cement board and leave it at the 1/4 inch spacing or can I go smaller on the spacing and basically lay the tile on the cement board with a small portion of the bottom part of the tile being attached to silicone?

  15. Tom says:

    Glad I found your site and post! I have a very similar situation. If some studs are not even with each other, do I make shims of various widths to make up the difference? I was planning on using stainless steel screws and stainless steel washers to secure my tub. I’ve read where some people suggest notching your studs so the part of the tub flange is within the notch even with the studs. It sounds with the latter a person’s shimming is reduced. A good idea?

    I understand too the vapor barrier goes over the flange into the tub side. Since the tub flange isn’t too deep, how is the 4-6 mil plastic secured over the lip?

    Thank you!

  16. Matt says:

    This is a bit off topic but still relevant. Every stud where the tile is going to go is 16″ on center EXCEPT the stud spacing for the plumbing. That for some odd reason has 19 3/4″ between the studs. Should i add a stud to make these 16″ on center? Or is there some other way to do it?

  17. tom says:

    I remove my old tub. I only have 59 1/2 inches stud to stud.will a 60 tub work if i trim down the stud? If so should i trim only the wall with no pipes on it, or cut both.

    1. Depending on your tub you may not have to plane the studs down.

      But if you have to go that route I’d recommend using an electric power planer on the studs with no pipes.

      Chances are pretty good that you’ll only have to plane a small portion of the studs and therefore not ruin the structural integrity of the framing.

      Keep us posted Tom

  18. Pauline Dotte says:

    Thanks so much for all of the detail you go into for installing this tub (we are installing the same thing) and the photos! We were really struggling with the way the lip of the tub was attached to the studs and how the backerboad would fit – I think we can finally move forward with this project!

  19. Sheeley says:

    Is there a picture of how the nail looked after the shim was installed?

    1. The nail for attaching the screw should be depressed under the shim, that is not sitting on the surface of the shim. Hope that helps ๐Ÿ˜‰

  20. Emma says:

    Hey Jeff,
    My studs on the back side of the tub wall have a section that is 21โ€ between the studs. Would I need to add another stud or will it not be a problem?

  21. Tony says:

    Hi Iโ€™m putting a shower on an old walk in closet. Rather than tear out the plaster and lathe, I put redguard over it and then lathed out over the shower base lip and cement board over that. The result is nice square plumb and flush walls but there now is now about a sizable gap between existing walls and cement board. Ideas on filling it?

    1. Hey Tony, yes, that’s an issue. The best option is to either feather the walls with joint compound or add another layer of drywall but that would likely interfere with your door casings.

Leave a Reply

Your email address will not be published. Required fields are marked *