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Baihelen · Feb 21, 2007, 09:53 AM

Lately, there is water dripping sound in the wall of my bath room immediately after shower or toilet flushing or water sink used. After about 5-15 minutes, then the dripping sound stopped. I suspect there is a leak in PVC drain pipe or fitting in the wall. However, there is no sign of water outside the wall. I had called a plumber, He told me that it is PVC pipe expansion or contract after water running. However, I never heard such sound in the past six years since I moved in this house, even in harsh winter. The sound are so regular and does not like PVC pipe expansion or contract. And the sound is getting louder and louder day by day. I did not open the wall currently since I replaced new carpets lately. I want to know is it a real PVC pipe leak or PVC expansion and contract? And then decide to open the wall or not. Wish I could have a right answer.

Thanks!

Helen

doug238 · Feb 21, 2007, 10:43 AM

Your plumber is right, the proof is, there is no water showing up.

MPB745 · Feb 24, 2007, 10:54 AM

Originally Posted by Baihelen

Lately, there is water dripping sound in the wall of my bath room immediately after shower or toilet flushing or water sink used. After about 5-15 minutes, then the dripping sound stopped. I suspect there is a leak in PVC drain pipe or fitting in the wall. However, there is no sign of water outside the wall. I had called a plumber, He told me that it is PVC pipe expansion or contract after water running. However, I never heard such sound in the past six years since I moved in this house, even in harsh winter. The sound are so regular and does not like PVC pipe expansion or contract. and the sound is getting louder and louder day by day. I did not open the wall currently since I replaced new carpets lately. I want to know is it a real PVC pipe leak or PVC expansion and contract? and then decide to open the wall or not. Wish I could have a right answer.

Thanks!

Helen

Originally Posted by doug238

your plumber is right, the proof is, there is no water showing up.

Is the sound from pipe movement or from actual water dripping slightly in the wall?

One shower in our house had not been used in 8 months and when I took a five minute shower, had some minor dripping from the pvc drain pipe onto the unfinished laundry room directly below the drain.

Do you think this is from unuse of the shower, expansion contraction, some combination thereof?

Any suggestions?
:confused:

doug238 · Feb 24, 2007, 11:09 AM

If no water showing up then it is likely just expansion and contraction.

MPB745 · Feb 24, 2007, 01:11 PM

Originally Posted by doug238

if no water showing up then it is likely just expansion and contraction.

So, Doug, since I have a little dripping water, there is a leak, right?

Not just because we have not used that shower for 8 months?

doug238 · Feb 24, 2007, 02:28 PM

Water showing up indicates a leak

doug238 · Feb 24, 2007, 02:29 PM

I posted this on another string...
Remove the shower grid and pour water from a bucket through a funnel into the drain to test the pipe. Do not let watyer get on the shower floor. If this does not leak then get a cloth rag, wet it, put it in a plastic baggy and stuff it into the drain to stop it from draining. Then use a bucket to fill the shower floor about 1 to 2 inches and wait. If the pan leaks this will reveal it. If this is the problem you will be replacing the pan, the shower floor, and 2 or 3 rows of tile. If all these pass the test, use the bucket and fill it from the shower. If that leaks you may have to either repair the shower valve or open the wall and repair the shower riser.

Baihelen · Feb 26, 2007, 08:18 AM

Thanks for everyone's advice. I have used this shower everyday until lately I heard obvious and quick dripping sound. The sound of water drip is from drain water from tub and toilet also, not just shower. There is aluminum metal plate on that area. The dripp sound is like water dripping on the metal plate. It happens once the water in hand wash tub goes through drain, even just 1/4-1/3 hight of water in the tub. The water did not show outside, may be the minor water not spread out. But the plumber is still insisit on the PVC pipe expansion and contract. I may need to open the wall to prove it. How your guys think about it? :confused:

doug238 · Feb 26, 2007, 08:53 AM

If you have a cover that you can remove and give you access then do it for the peace of mind.

MPB745 · Feb 26, 2007, 09:51 AM

Originally Posted by doug238

if you have a cover that you can remove and give you access then do it for the peace of mind.

Doug, when you say pvc contract and expansion, what is the noise from? Just the pipe joints moving (but no water leaking) or from water coming out while the pipe is contracting or expanding?

:confused: :confused:

doug238 · Feb 26, 2007, 10:01 AM

I had a customer once that said his pipes were making noise and he wanted it stopped. It turnout to be his hot water cpvc piping. The straps and wood penetrations were too tight. It is a large house in downtown atlanta. I showed him how when the heat hit the plastic pipe is expanded slightly and made a squeeking noise and a dripping noise. His whole 'new' house was piped that way and it could not be repaired economically. He was not enjoying his almost million dollar home. Pvc does the same thing but not as noticeable because it is larger and the whole pipe does not get as hot. The rule of thumb here is this, if it makes noise and water showing up, it is leaking. If it is making noise and no water showing up, it is likely expansion and contraction. Basically, it is plastic squeeking on wood.

iamgrowler · Feb 26, 2007, 04:23 PM

Originally Posted by doug238

i had a customer once that said his pipes were making noise and he wanted it stopped. it turnout to be his hot water cpvc piping. the straps and wood penetrations were too tight. it is a large house in downtown atlanta. i showed him how when the heat hit the plastic pipe is expanded slightly and made a squeeking noise and a dripping noise. his whole 'new' house was piped that way and it could not be repaired economically. he was not enjoying his almost million dollar home. pvc does the exact same thing but not as noticeable because it is larger and the whole pipe does not get as hot. the rule of thumb here is this, if it makes noise and water showing up, it is leaking. if it is making noise and no water showing up, it is likely expansion and contraction. basically, it is plastic squeeking on wood.

And if the installer had followed a few simple installation procedures recommended by the manufacturers (expansion loops, sNails instead of two hole pipe straps and insulators) he wouldn't have heard a thing.

The only applications I'll use CPVC for is T&P drains and condensate drains.

ravengirl21 · Apr 13, 2010, 11:50 AM

Did you ever find out? Was it a leak or expansion/contraction? I have the same issue right now and I was wondering the same. I thought it was expansion/contraction, but now I am thinking it may be a leak. I have not found any water outside of the walls yet, but the leak may not be big enough to cause that much yet. The dripping sound begins when we run shower/sink/toilet in the bathroom and ends within 15 minutes or less after running the water. The drip sounds like water dripping on wood. Just wondering if this problem was ever figured out because it could help me with mine as well.

dillon21 · May 6, 2011, 09:30 PM

I have a simlar weird leak going on, its behind the drywall under the bathroom sink. Nothing is leaking under the sink. I noticed the wood on the cabinet getting waterlogged looking so after not seeing a thing leaking had to cut the bottom of the cabinet on the inside to see. It was wet! No water is running so it doesn't look like a pressure pipe leak. I dried it real good. Later my wife used the sink and toilet and a pudle of clear water appered! I dried it again. We used the shower and toilet, no leak. We even ran the sink water for 5 minutes, no water showed up, this is crazy. I know the problem is a drain problem behind the drywall, what could it be? Thanks

afaroo · May 7, 2011, 04:08 AM

Dillon21 originally this is a 4 years old thread I would suggest that you start a new thread that it be on top of the page and one of the experts will respond to you soon, Thanks.

John