I am renovating a ground floor bedroom and it involves replacing a drop ceiling with a Sheetrock ceiling. Above the bedroom is the upstairs bathroom. Over the years I have noticed three different drop ceiling tiles with water stains. Upon removing the tiles, two of them are where 45 elbows are in the ½ inch copper pipe for water supply lines, the other tile is long runs of the same copper pipe. So my question is how do I check for a leak? Obviously I want to make sure this leak is resolved before the Sheetrock goes up. With a visual I cannot see any drips or even a partial leaking pipe. The leak could not have been severe as the tile would be molded and damp. A friend suggested it could be condensation on the pipe. I will add this is a 2nd home and I am not always there. I keep the thermostat at 50 during the winter to avoid frozen pipes. One thought is to do away with the copper elbows and replace with pex, but this is not my area of expertise and would like a professional opinion. Thanks in advance. Curt.

I would tend to agree with the condensation causing the stains. Could you insulate the piping ?

What fixture do the 45s feed and is there a shower valve in the wall above the 45s. It could be a valve inside the wall that has a bonnet/stem seal leak. Just a thought. First know what those 45s feed, then go from there to solve the leak. You say you are not there all the time, do the tiles dry out between your visits. If so this would point to a leak only when you use the fixture....you have to be a detective with these problems and a process of elimination. Good luck.

Yes that would be easy to do. Thanks for your input about insulating the pipes.



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Srolen,

Yes the two 45s do feed a shower directly above. The end opposite is a single 45 that feeds the toilet. These are the only tiles that were stained. I have never noticed the tiles actually wet only the stains. The tiles are all removed now. I will try using a ladder and prop a pan or bucket under the pipes and turn on the shower to check for leaks. I am just hoping this not an intermittent thing. You should have a leak or not I would think. I did see a video where a common problem is the bathtub spigot that was not caulked behind it easily causing water to drain through the opening. This is something I will check as well. Thanks for your input.



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Condensate sounds like the most likely cause. A leak from any where would show rather quickly even if intermittent. Condensate is slow usually only occurs on coldwater lines during hot weather or if downstairs heat is kept high, don't forget that heat rises! Do stains appear in summer. I would leave ceiling open to confirm.