I noticed a bubble in our downstairs ceiling and there was water dripping onto the floor. I cut a small hole in the drywall to see if more would rush out but it seems to be just wet. There is insulation so I cannot tell how much there might be. The leak is right under our upstairs bathroom, and I had just finished a shower when I noticed the leak downstairs. Where do I start on diagnosing and fixing this problem?

Here's some pictures

  • 1
    You will have to cut a slightly larger hole and remove the insulation to hopefully expose the piping and see where the leak is coming from, Only then can you talk about fixing it.
    – DJ.
    Commented Oct 12, 2023 at 0:16
  • It can be a pain to cram a full length batt of insulation back into the ceiling, and who knows if it actually gets to the end of the cavity again or is all bunched up short of the end. It would be wise to cut away only a section of the insulation in the neighborhood of the hole in your ceiling.
    – popham
    Commented Oct 12, 2023 at 7:16

1 Answer 1


First I would check thoroughly to make sure that you don't have water coming out of the shower onto a wall or floor. Maybe if there's a tub in the shower, water is collecting on the lip of the tub against a spot that has a caulk failure and is entering the wall. Look everywhere that's wet for problems.

If I couldn't find anything that way, I would try to remove the escutcheon in the shower to expose the valves and look for signs of water next to them. If you're lucky and you have an access panel behind the shower, start there.

If you have continued water and and you're relatively certain it's not just overflow or a tile failure, then you're going to have to open something up to find it. If it's a drain leak, you'll probably have to open up the ceiling.

I personally hate working on ceilings and would consider opening up a wall behind the shower before I opened up the ceiling (especially if it's in a closet and I won't have to do a perfect job matching paint)

As mentioned in comments, the other way to go here is just to realize you're already forced to repair the ceiling. Opening that up to a usable size isn't going to change the repair significantly. Since that's where the damage is, you should at least be able to see where the water is coming from and use that to plan the next move (or if you're lucky, repair from that spot) rather than just be guessing.

  • especially if it's in a closet and I won't have to do a perfect job matching paint +1
    – Cheery
    Commented Oct 12, 2023 at 0:26
  • She's already stuck working on the ceiling, no? The prep work for patching will also provide access for locating the leak source.
    – popham
    Commented Oct 12, 2023 at 0:42
  • True, and that may really be the way to go. If you're comfortable with ceiling work, starting there is probably best. But if the problem is elsewhere and I just have to patch the ceiling hole (and not deal with insulation and more drywall over my head), I'll probably investigate that first.
    – BowlOfRed
    Commented Oct 12, 2023 at 2:32
  • "Comfortable" working on the ceiling or not, there will be some ceiling repair to do. Not only open up the current joist bay to get the nasty, wet insulation & dry wall out, but open one on either side, too, to see if the water ran horizontally across the floor before coming down. Water can be insidious that way...
    – FreeMan
    Commented Oct 12, 2023 at 15:30

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.