There is a very narrow crack in my living room ceiling, pictured below. My concern, as you can imagine, is not so much the crack itself but the discoloration on either side.

enter image description here

I am frankly not sure how long it's been there (possibly already when we moved in, around 8 months ago), but it was definitely like this a few months ago with no changes that I've observed.

If I'm measuring correctly there's nothing in particular on the second floor directly above the crack, but it's just a couple of feet from a rather heavy whirlpool tub.

My question is, does this need attention, and if so what kind of contractor (if any) should I be calling? (Flooring seemed right to me, but when I look for flooring contractors, they seem mostly to specialize in installation/refinishing, and it's not clear how to tell which of them would do a credible job assessing this.)

  • I can get no sense of scale from that photo. How long is the crack?
    – isherwood
    Commented Jan 23, 2017 at 19:08
  • Fair point! I think the discoloration (the middle third of the photo) is about a foot long. The crack itself is longer.
    – D. Savitt
    Commented Jan 23, 2017 at 19:23
  • have you used the tub more then a few times since moving in? I would run water upstairs and see if it gets any worse. Or you can just punch a hole with a screwdriver to make sure theres no moisture still up there, and that you could repair yourself.
    – n00b
    Commented Jan 23, 2017 at 19:30
  • I'm sure it's just a handful of times that we've used the tub as a whirlpool (e.g. with more than a foot of water, and jets on), but we use it daily as a shower and/or a regular bath.
    – D. Savitt
    Commented Jan 23, 2017 at 20:08

4 Answers 4


There is, or has been a leak - those come from plumbing or from the roof, or occasionally from a water spill on the floor above that was not cleaned up quickly.

If you are quite certain it's not expanding, and you never see or feel moisture near it after the tub is used, or after a rainstorm, you could hire a painter and hope that it was from a one-time spill event.

If it comes back a plumber (or a roofer) seems like a requirement, and for the plumber to see what's up you will probably need a drywall contractor to patch the holes the plumber will need to make to find out what's going on and fix it. You do not want to pay plumbers rates for drywall repair.

You'll still need a painter, but the drywall contractor might also do painting.


I don't think you are ready for a contractor yet. I would scrape that section and add some new drywall mud with a piece of tape and see if it cracks again. There are kits at big box stores for $10.

I would then keep track of the area and your whirlpool usage. Filling a large whirlpool tub of water is a ton of weight - a lot more than the tub itself. Adding two or more adults to the area and that's a lot of weight. My point is that your crack is really straight and I would bet money it is parallel to the joists above. I think you are getting flex on one of your joists and it is pushing off a little. (you may have some very slight water issues but this is hard to tell - you would often see way more yellowing if there was a leak. It could just be floor splash from bathroom though)

If your crack doesn't come back, then get a drywall guy to integrate the texture on the ceiling better. If crack does come back I would probably reinforce the joists from below which means you will need a general contractor - someone familiar with weight bearing and framing. He should be able to handle the drywall after reinforcing the joists.


If it is beneath the bathtub there is a fair chance that the leak is a result of a poorly sealed overflow drain. It is pretty easy to check, just run the bathwater above the overflow drain and see if you can hear a drip at the site of the crack or discoloration occurs. You can get a new overflow drain gasket at the local hardware store for somewhere in the neighborhood for around 10 dollars and the replacement is a fairly simple process.

  • 4
    Water is terribly good at travelling many metres from the source before you see it. Given the proximity to the bath upstairs, its a prime suspect.
    – Criggie
    Commented Jan 23, 2017 at 23:36

That color around the crack means moisture. Maybe from a leak, maybe from being careless with kids in the tub, etc.

What I would do, personally, is cut away the dry wall in that area, from one "beam" to the other in the ceiling, the entire length of the crack. As long as your area being cut out is less then one sheet of drywall, your not spending any "extra" money. If it's larger then a sheet of drywall then you will need to adjust, but it shouldn't be.

The reason I say cut out such a huge piece is simple. Proper repair will have you do that anyway. A patch job that is more then just Spackle, means first cutting a easy to fill shape. From beam to beam, is damn easy, you don't have to do any weird stuff to hold the patch in place. Next is the water. With that large of a section removed you can go turn on every faucet in the house, one at a time, for at least 10 mins. Then check to see if the "beams" get wet. It's really important to run "every" faucet because water can go an insanely long way. Water on one side of the house could be clear from the other side. There is no reason to run water on the first floor. Water can "go up" wood, but it wouldn't look like that and you would see the colors along walls.

With the big hole, you should be able to get a general idea where the leak is coming from. If you don't see any water, and you don't think there is a lean then apply a generous layer of flour (for cooking) to all the "beams" in that area. The flower will get wet if there is even a little water.

If you have a leak call a plumber, they will appreciate the big hole. If you don't have a leak, then check the caulking around the tub. You should be able to pour a bucket of water on the floor in the bathroom and it should stay on the floor, not soak into it. Don't pour a bucket. But with the flour in place maybe pour a glass. If you see water then, you probably need to re-caulk your tub. This is an easy one if you have kids. They splash water, and it goes under the tub into the floor and "leaks" to the floor below.

If you don't see water then, then just move on with the repairs. If you do see water, then repair the leak(s), and move on with the repairs.

To repair the now gaping flour filled mess, you shop vac up the extra flour. If it didn't get wet it should be really easy. Then you give all the wood inside the area a really good spray with bleach (if there was water this will really help avoid mold). Put the new drywall in place and secure it (screws work best, but nails are ok) Then finish it like normal. Drywall tape, paint and blend.

  • 1
    I would put good money on that crack being at the joint between two drywall sheets. 1. Cracks are most likely at the joint between two sheets. 2. Water is most likely to find its way through at the joint between two sheets.
    – AndyT
    Commented Jan 24, 2017 at 12:16

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