[ellie09]

We moved into a new house about two and a half months ago. When we moved in, there was a water spot on the ceiling of the dining room. I am almost positive that it was not there four weeks prior at our inspection. It is located under a bedroom floor, but is within a few feet of a bathroom. We have used the bathroom (sink, toilet, and shower) several times. The stain never feels wet or drips, the drywall feels normal (not soft at all), and there has been no change in the stain's color or size. My husband says to just paint over it since we have no evidence it is an active leak and if/when it comes back, we'll call a plumber. What do you think?

 

[Just Bill]

My guess would be a leak at the floor/tub joint around the tub. That is often overlooked and needs to be kept caulked. Keep in mind that water marks don't always show up directly under the leak. Water will often travel down joists before dripping. Cover the spot with KILZ or Zinser 1-2-3 before painting. Water spots will bleed thru most paint.

 

[Gary in WA]

As Bill said, a water leak. Check the gasket behind the shower valve/handle, the toilet seal, or a drain connection. Open it up and expect mold at least over to the bathroom. It will only get worse. Be safe, G

 

[ellie09]

GBAR--Bill said it could be water from the tub/shower surround and to re-caulk (right now it is only caulked half way across). We have no evidence of an ongoing leak after using shower, tub, and sink many times. Is it really necessary to tear everything out? I would do it if I had any evidence there was a leak. This looks like a one time thing because there is no evidence of more water, the stain darkening, getting bigger, etc.

 

[Gary in WA]

If you only noticed it a few times, chances are good that it just happened. You could leave it be, but I suggest you do this before you paint. Drill some holes in the wet area and let it ventilate for a week or so, to dry out. Then Spackle or mud the dozen 1/4" holes before you paint. During this drying period, if you smell mold or get sore throats or running noses, there may be mold.

Be safe, G