Water stain in the ceiling below a bathroom. Do you scan before cutting?

wedaken

I do residential plumbing service. One of the hardest questions to answer is, “Can you keep the hole small?”

There is a bathroom upstairs and a water stain on the ceiling below. The darkest part of the stain is not always under the leak. Still, you have to pick a place before opening the ceiling.

I am thinking about adding a thermal camera to my service tools. My plan is to scan the ceiling first. Then I would use a moisture meter on the areas with a clear temperature change. I would check a few normal looking areas too, just for comparison.

If that can narrow the search from half the ceiling to one small area, it would be useful to me. I know the camera will not tell me if the water came from a supply line, a drain, or somewhere else. That part still has to be checked.

For the service plumbers here, have you ever changed where you planned to cut after looking at a thermal image? What did you see on the image, and what did you find after opening the ceiling?

cm6230

I usually make a small hole and use an inspection camera, ridgid makes a great one. I haven’t used a thermal camera but I think I do have a cheap one I got off amazon lol

109A_5

Thermal imagers are fun and useful, although I have never tried your exact scenario. You may want to explore Borescopes too. A small hole and you can actually look around in the void. Some you can steer and also some have multiple viewing angles.

psb75

This is the first thing I say to the client, "Hey…its just sheetrock"…usually. I guess in some cases it could be plaster. Do as much verbal fact-gathering as you can. Past history of the installation i.e. "what's IN THERE"? Hot/ cold supplies, to what, shower/tub, toilet, vanity etc.? Type of plumbing? Pex, copper, PVC, cast iron etc. Don't rule out RAIN WATER if there is a vent or access to roof etc. How big, how recent is the leak? Episodic or long-time? Gauge the amount of moisture. Do your best first with words and info gathering. Then…make a hole. The damage you see, may be the lowest spot where the water has accumulated and NOT very near the leak! So I suggest making a BIGGER HOLE than you or the client want. After all…"Its JUST SHEETROCK." It can be repaired. I just did one of these. It was a bad pex crimp fitting done recently in a renovation of a vanity supply. The "stain ring" on the ceiling was quite a ways away from the drip—in a very deep ceiling cavity from the upper floor. Forget the thermal imaging, Get out your sheetrock "stab saw" and mind the electric wires.

Jamie Hall

More or less agree with all of the above… except I'd like to add to @psb75's comment a bit. Do all the research you can before you start bashing at things. The problem may not be something "in there" — it may be a more or less obvious (usually less…) problem in the exposed plumbing in the bathroom overhead. I've seen serious water staining from condensation on a toilet tank which dripped on the floor (in quantity), travelled along the floor, slipped down a water pipe though the floor and wound up three feet away…

hot_rod

https://forum.heatinghelp.com/discussion/comment/1908438#Comment_1908438

I agree that a large Sheetrock opening is no harder to patch than a small. If you need room to do the repair, a small hole gets bigger.

Sheetrock sells by the 4x8 or larger size, even for small repairs.

Ovviously check wax seals, leaks around tub trim, spouts and shower heads. Waste and overflow calking around the tub, etc.

Yes to an IR camera for this and many other uses.

Alan (California Radiant) Forbes

Does the leak stop when the fixtures aren’t used. If yes, it’s a drainage issue. Replace the wax ring on the toilet, check the overflow gasket on the tub, check the tub caulking before you open the ceiling.

If the leak is always there, it may well be a pressurized water pipe and you will have to open the ceiling to find and repair it.

Good luck!