Drip sound

[survivor2019]

Drip sound coming from upstairs sink. I can hear the sound in the bathroom and downstairs. When downstairs the noise is higher up the wall. After the water has been running a while the noise goes away. It starts with cold and hot water and only happens when the water is draining out from the sink. I drilled holes to look at pipes and the closest noise is at some copper pipes and a PVC. I’m assuming it’s the PVC but I thought the pvc was a vent pipe and not a drain pipe. I don’t see any water leaks and this has been going on since I bought the home over a year ago. Looking at picture the noise is all the way in the corner at the 3rd drilled hole. I can’t get a good pic of the pvc pipe next to the copper.

 

[Twowaxhack]

Probably the pipe expanding and Contracting against the framing.....

You would need to hear like a cat to hear a drip in a closed wall.

 

[survivor2019]

That makes me feel better. It’s a loud thump , I just don’t want to find out I have some rot going on because of it!

 

[Twowaxhack]

It’s pretty common when new construction guys don’t install the pipe correctly,......