Home built 18 months ago in Michigan. After 6 months or so saw a ceiling nail pop that looked wet, center of living room ceiling, got bigger over a few months to the size of a 50-cent piece. Dug out a smal circle of drywall, looked dry. Couldn’t trace the water from anywhere, such trace amounts. Left no trail. Plugged the area with toilet paper to see if it got wet, and it was bone dry that I could tell for a month, so patched it up and forgot about it. 3 months later it is back with a vengance, the size of a brick now with a small area of green-ish tint. Spot is below laundry, but I checked that area and no signs of leaking. 2 baths and laundry on second floor above leaky ceiling, but not directly above. Question: How do I find the cause of the water if it isn’t readily visible when I cut open the drywall again? Any tricks I should follow, or do I have to tear apart half the ceiling to really get a look? Thanks!
Replies
WM, Sometimes those type of "leaks" come and go minimally because of volume in drain lines. Could be a screw through some pvc, leaks when the water level gets high enough with enough "push".
or the same with a screw in some copper, material drying out is moving the framing the pipe is fastened to just a bit.
or, tub/shower leak.......either out over the rim,down the face and entering at the floor/tub interface.
The slight green you see could be corrosion on copper (but your piping is new) or perhaps water with soap residue.
Cutting the ceiling might not show its location but could help you find the source. I think I'd measure it out real close and try to find if I couldn't locate it more exact upstairs. If in the vicinity of the washer, cut the wall behind to take a peak.
If you are needing to do more to repair the ceiling than seal and repaint-go ahead and open that up.
Thanks, Calvin. Since the original problem happened under first year of warranty the builder is still involved, but doesn't really have an idea how to find water source (his words). We will in fact have to cut out a few square feet of ceiling just to be sure, so are you suggesting cutting out more to get a better look around since we have to cut out some anyhow? If we don't see any trail to follow to the source, that makes me nervous. I hat to go cutting into the walls and/or floors of the bathrooms and laundry room. Sheesh!
One's first suspicion would
One's first suspicion would be a tiny leak in a drain pipe. Moisture can follow the bottom of the pipe 5-10 feet from the actual leak to the point where it drips off. But if there's no drain pipe near the spot then not likely.
However, a wire can also serve the same function -- to conduct a drip of water many feet from its source.
If this is near a upstairs wall, consider a leak in the wall, or moisture getting on the floor and leaking down at the floor edge. Also consider the possibility of a roof leak (or condensation in the attic) that's leaking down a wall, perhaps following a wire or pipe.
I assume there's no dryer vent or ductwork in the area -- condensation in that could cause the problem. Had a problem once where a malfunctioning humidifier on the furnace caused the ceiling to get wet in part of the house.
What is in the joist bay directly above the spot, or within a foot or so in any direction? (Keep in mind that moisture on drywall may hit mid-sheet and not first become apparent except at the seam a foot or two away.)
Thanks for the reply, Dan. Bay above spot open, just fiberglass batts for a little sound dampening (not that effective, btw). Maybe the first step should be to open the ceiling a few feet in order to get a better look and maybe see a water trail. If the green is from copper we could have a bit on joists or sheet rock leading to the spot. Is that what you would do first, open the spot larger than a square foot (like the first time)to get a better look? Thanks again.
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Submitted by westmich on Mon, 12/14/2009 - 07:21.
Dan mentions vent stack or perhaps a condensate leak from a dryer, something you should consider. Prior to the first and later "leak" staining, was there a driving rain in your area? Bad seal at vent boot or other roof penetration would show signs of water once in a while.
If you measure out the location to get an idea of where upstairs it MIGHT come from- Since it's new, can you overlay prints 1st floor and second to help you with identifying the location?
Best of luck.
One thing to remember is that it's really no more work to repair a 2-foot hole in drywall vs a 6-inch hole. Don't tear down the whole ceiling unnecessarily, but open up a big enough hole to be able to tell something (and to be able to read the drip pattern on the back of the removed piece).
If the first leak was a year ago, and it has reappeared, I'm thinking weather temps condensation related
Maybe, for example, a tear in the dryer vent is letting moist air out into an area that gets especially cold.
I'd use an infrared thermometer for my first "scan", maybe waiting for a really cold day, and scan the ceiling below and walls and on the upper floor for a really cold section, such as an unintended "plenum" between 2 joists getting coled because of some gap to the outside.
I am also imagining something realted to condensate.
Dryer hose could be providing the dampness, and a cold supply line making the dew point collector to drip on down.
I also once saw a leak that was at an elbow in the copper where the plumber had forgot to solder it entirely. Somehow, the way it was propped in place, it never leaked for years, then suddenly started dripping. There was not a bit of solder there.
Thanks, RJW. I will locate an infrared thermomoeter and do as you suggest along with takivng a visual exam of the area once the drywall is cut out of the ceiling.
I am not convinced that it ever really stopped. My thought is that it is so slow that it takes a while to go through the drywall. The first spot was actually a wet nail pop that slowly, over months, to the size of a Kennedy coin. The initial leak could have been around all along, just really slow, and between the first and second appearance it has grown in all kinds of weather and temps. When the drywall was replaced it took about a month for me to notice it again, then it really grew. But it is possible that the top side of the drywall began to get wet right after the initial ceiling drywall spot was repaired.