Finding a water stain source on a ceiling

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Posted by: from Newmarket
1/6/2012 at 12:01:57 AM

I will try to be concise (if I can!). I will be visiting a customer next week to try to find the source of the water causing stains on her living room ceiling (I did an initial look see). In a nutshell: three separate stains that are fairly light in appearance, stains are long and thin (indicating that the water is travelling - probably along the joices), stains start several feet from the nearest wall and are several feet apart. While there is a bedroom directly above the living room (the ensuite for the master bedroom is the closest upstairs washroom and it is directly above the main floor powder room), there is no indication that there is water leaking (all caulking is in great shape with no cracks or separations, the floor is ceramic with good grout and the bathroom it self is about 6 feet from where the stains on the LR ceiling begins). In the powder room, there is an access hatch in the ceiling (owner didn't even know it was there!). I was able to get part way in to look around. There is good visual access and again, there are no indicators of water leakage or damage. The topside of the ceiling drywall is perfect, no moistrure on water or drain pipes.

So, any suggestions as to what I should look for? I was planing on making some small holes in the ceiling and using an inspection camera to get a better look in the areas of the stains. I wonder if perhaps the previous owner had water leakage problems and then repaired them without painting the ceiling. Current owner said if so, then this was not disclosed.

Thanks for any feedback or suggestions.


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Viktor from Plumber Master in Mississauga
Date/Time1/6/2012 at 12:13:36 AM


Looks like your idea of making small hole and using small camera is reasonable. You can save time run all plumbing fixtures. There must be somewhere a crack or pipe sections not glued properly. May be problem with toilet gasket. Also water may travel far away from the leak source, so it may be needed to cut as much drywall as necessary to see the leak source. Make sure drain in bathtub is tightened properly - there was cause of the leak number of times in my practice.


Plumber Master

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Date/Time1/6/2012 at 12:27:51 AM

Thanks, Victor.

The only thing I know for sure is that water travels and thus can be difficult to pinpoint! I appreciate your suggestions.


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Date/Time1/12/2012 at 1:11:48 PM

Hi Brett,

Not sure what the outcome was to your investigation but a thermal imaging could possibly find the source of the leak. However, there are a few variables that need to taken into account before going forward with thermal imaging to locate water leaks.

For example, as mentioned above, if the leak is not active then infrared will most likely not pick up the surface temperature differential.

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