dripping sound inside wall

Question

I'll try to get everything in here, yet be concise.

This is a 3-story building, plus basement/underground parking. I'm on the 2nd floor, studio. Same layout above and below. Exterior wall to balcony; all others interior. Kitchen and bath share a wall (and also run along interior wall for hallway). The drip sound is from the wall between the kitchen and bathroom.

Kitchen sink is on an island "wall" not attached to the "problem" wall. Bathroom sink and toilet are on the wall opposite the "problem" wall. I was thinking there wasn't any plumbing in the "problem" wall, but my mom pointed out the sprinkler system. And, duh, the shower faucet is on that wall (drain is in middle of tub, though).

The drip is extremely intermittent. It seems to occur at any time of the day (or night), and does not appear to be related to water running or having been run recently. It SEEMS to be coming from/hitting somewhere near the ceiling. Also, several feet to the side of the shower faucet. When I hear it start, I've listened to see if anyone is running water (even going upstairs to listen) and there is never water running.

I've talked to the guy upstairs and he also hears it. I haven't yet asked him if he can pinpoint "where"--as in, does he hear it towards his floor or not? (to 'correspond' with my sense that it is near my ceiling) I haven't talked to the guy on the first floor. If he doesn't hear it, then....well, it helps isolate the problem, I guess. Oh--I've listened in the hallway downstairs and not heard it. But I also listened in the hallway on the 3rd floor and did NOT hear it; but when I asked the guy, he did hear it inside his apartment.

The building is about a year old. The drip/sound occurs during the summer and now (so, when hot or cold outside). I've seen no evidence of water damage on either side of the wall. I first heard it....about 5 months ago. I wasn't here before that (I am first tenant in this unit). If it's been doing it since construction, I'm not sure if that would be enough time for damage to show on the "living" sides of the walls? I would think so, but....

Obviously, with sprinklers in the wall, there are pipes. But I can't think why those pipes would have water moving through them 2 or more times a day. Wouldn't water just sit in those pipes until needed, if ever needed?

The sound -- like big drops. Nearly always the exact same speed, although I think a couple times it was quicker. It lasts anywhere from a minute or two, to 15 minutes or more. I'm up all night--it often happens in the middle of the night. No one else is up and running water, and I would not have run the shower for...hours.

I'd like to figure out WHAT this is, because I really do not want them coming in here to tear out the wall to try to diagnose it. There is no maintenance person on-site, so I can't just get him/her when it decides to drip.

Any thoughts??

Answer 1

If it occurs during summer, and days when you run your air conditioner, its likely they fed the condensation drain pan to the house drain. Try turning off your AC for a whole day and see if you ever hear it.

Its also possible that its someone else's AC unit that is drained to your drain, or in a multi-unit building, the common drain that happens to run through your wall.

Answer 2

Sanity check: Are you sure it's actually dripping? Hot-water pipes expanding/contracting due to temperature changes can sound very similar to a drip as they slip/stop/slip against their supports, and that's more likely at this time of year when the difference between a pipe with hot water flowing through it and one that's been sitting for a while is more pronounced. (And when the heating system is turned on, if you have a hot-water system.)

Answer 3

A small leak can drip for a LONG time before it shows on the other side of drywall, particularly if the drywall is double-layer firecode (as may be the case in an apartment building, depending on local codes.)

One possibility is that this is a condensation drip of some sort - from a dryer duct or bathroom vent fan duct. Then again, it could be coming from the roof leaking.

It may be pooling somewhere for a while and then "releasing" the pool/puddle in a series of drips - so it could be widely separated in time from the actual source of water, be it the neighbor's pipes, a vent condensing, or rain.

Answer 4

posting an "answer" so i can address all 3.

it can't be the air conditioner, because it's still happening. and because it happened in the summer too, i crossed out "hot water moving thru cold pipes." that's why i noted that it's been happening over at least 5 months.

the sanity check is funny! i know when it started and my folks were here, i immediately asked my mom if she heard it too. she and dad both heard it; and the guy upstairs hears it. but 'sanity check' for "is it actually dripping?"--i've read about the pipes contracting/expanding and then rubbing, or via movement, making a "dripping sound."

i wish it could be that, but i really don't think so. for one thing, i paid more attention after posting my question. there are more times when the 'dripping' starts out quite fast, then slows to its "regular" rhythm, then i was thinking there were. the difference in speed also makes me question the idea of water pooling somewhere until there is X amount, and then dripping for a bit.

as far as leaking from the roof--thought of that too. but it's been continuous, even over the summer when we went for weeks without rain.

this is driving me crazy.