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I was getting ready to tile my basement bathroom and noticed the wall wasn't as flat as I expected. I cut in a hole to take a look and got a nasty surprise. The drywall in my bathroom was glued to the studs rather than screwed. As the house settled over the past 50 years, the paper backing on the drywall tore off at the glued spots leaving a 1-2.5" large gap where it has bowed outwards from compression.

I've been able to use drywall screws to get the upper parts of the drywall properly secured to the studs but as I work my way down the bow out is too significant and the screws just pull through.

I had been thinking of trimming the bottom edge of the drywall to allow for some downward give. It wouldn't be visible due to baseboards but I'm not sure if that would create moisture issues in the long run.

Do I have any options other than tearing the drywall down and redoing it?

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  • It's a bathroom floor, it's bound to get wet eventually. I suppose if I ran a bead of silicon along the bottom of the baseboard that should keep it dry.
    – Myles
    Jan 12, 2021 at 18:50
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    It is a bathroom floor before cutting it and making it shorter. Sure, caulk the the bottom of the baseboard trim.
    – Alaska Man
    Jan 12, 2021 at 18:53
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    With you putting in screws that is a lot of the process to replace I would cut out and replace a entire sheet , possibly 1/2 sheet horizontally, I don’t like Sheetrock horizontally but do it on occasion and a slight gap at the bottom / not touching to prevent possible wicking of moisture from the slab this way you have a good surface to work with and zero bow. Most math rooms will only take 1 possibly 2 sheets doing it this way.
    – Ed Beal
    Jan 12, 2021 at 19:00
  • @EdBeal Mudding and taping is that one thing that I completely hate. If it comes to that, I'm paying someone else to deal with it.
    – Myles
    Jan 12, 2021 at 19:36
  • Step one: figure why you have the largest separation that I've ever heard of. Step two: scream profanities because you now see cause to gut the entire bathroom, if not the entire house.
    – Mazura
    Jan 13, 2021 at 1:45

2 Answers 2

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Trimming the bottom will not create moisture issues--nearly every wall in existence has a gap at the bottom. If you're relying on drywall to handle moisture you should hang up your hammer.

Trim away, and if the drywall offends thee by refusing to lie flat, pluck it out. Drywall is cheap and if it's behind tile anyway you can patch in as you see fit. Either cut on studs and patch it in, or cut between studs, float new backing, and screw it all together. Drywall behind tile doesn't necessarily need to be taped. If anything, use fiberglass mesh in your tile mortar.

Also, bathrooms are not boats. They needn't float. I've built and owned hundreds of bathrooms and I've never caulked baseboard. I'd rather have some airflow after a splash situation than a sealed floor that takes forever to dry. You will not keep it from leaking if you flood the room.

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    I trimmed it and got it flush to the studs. On the worst part after having a couple screws pop through I ended up putting in sets of three screws a few inches apart and turning each a turn at a time. It was slow but it's done and ready for tile.
    – Myles
    Jan 14, 2021 at 18:44
  • That's a good strategy. Another is levering off an opposing wall with a long block of wood and a leg.
    – isherwood
    Jan 14, 2021 at 19:22
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How bowed the drywall is will determine if it needs to just be replaced. If it’s under tile I’d just replace. Tiling over anything that is not flat will just cause a bad finish and a headache.

As for fixing the drywall without having to replace, you can dampen the drywall a bit. Don’t soak it, just mist it a bit let it sit a bit and continue until it gets enough flexibility where it won’t break or crack and you can push it back into shape. Then get a 2x4 and lay it across it. Secure the 2x4 to the wall studs so that it is holding the sheetrock flat. Then dry it with a heat gun or fan so that it does not sit moist to long.

It won’t mold and it’s not going to cause any problems. The only issue you might have is a water stain that will need to be primed with Kilz original. If it’s a very light water stain you can clean with clean or prime with a latex primer / sealer. You may not get a stain at all. This is an alternative if you don’t trust your tape and bed skills.

Good luck.

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  • The fan is a good suggestion. The heat gun not so much. It takes a long time for moisture to be drawn from drywall, and you can't really sit there that long.
    – isherwood
    Jan 24 at 17:51

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