Obviously it has something to do with water, but I haven't been able to track it down.

Basically, whenever someone turns on the water in my house, I hear a dripping sound coming from the ceiling above the living room. At first it sounds like a fast drip, then gradually slows down and stops. This is over a period of 30-45 seconds. If the water's running longer than that, there is no dripping sound.

I've gone up into the attic to look around but we haven't been able to replicate the issue while I've been up there. Whatever is causing the noise apparently has a "cooldown" period of some sort.

What could this be? At first I thought it was a leak, but then wouldn't it be dripping all the time and not stop after 30-45 seconds while the water is still running? (and shouldn't I have had a flooded attic by now?).

  • 3
    if its hot water you are running then the dripping might go away- micro leak. when the pipe expands it tightens and stops the leak.. jsut listen where it is- then go there and look for evidince of water.. if you cant go there where the leak sound is.. time to start removing panels, floors, etc.. dont ignore it-- water damage is very serious!
    – Piotr Kula
    Commented Aug 23, 2011 at 10:14

1 Answer 1


Sounds like a pipe expanding or contracting to me. When the water runs through the pipes (even the drains), the temperature change causes the pipes to move. Usually where they are passing through a wood surface, you'll hear an occasional sound, not unlike a drip, that will stop when the pipe reaches it's final temperature.

If the sound coincides with the hot water reaching the fixture (or extra cold water from outside in the winter) then you shouldn't have anything to worry about.

  • ah yes- possibly that ticking sound i hear in my floor when my central heating turns on and my whole house starts creaking.. gotta love wooden constructions...
    – Piotr Kula
    Commented Aug 23, 2011 at 13:05
  • I am planning to head up into the attic sometime this week to take a look. Your explanation sounds plausible because we don't hear the noise after we turn off the water and turn it back on a few minutes later. The "cooldown" period I mentioned must literally be the period during which the temperature of the pipe goes back to normal and contracts. Is this constant expansion/contraction normal? Any recommendations on how to stop the sound or ensure that the pipe(s) won't expand/contract themselves to death prematurely? Commented Aug 23, 2011 at 13:56
  • It seems to be pretty normal with copper pipe and wood framing. If it's really bothering you, you can find the location it's sticking/slipping and put something like a copper plate on the wood to allow the pipe to slip easier (check for compatibility if you use different types of metal). I've heard it in homes older than I am, so I doubt there's any risk of premature failure from this.
    – BMitch
    Commented Aug 23, 2011 at 14:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.