: Hello, I'm doing a repipe on the second floor bathroom, with copper and adding a shower. I've noticed that when someone runs water in say the downstairs bathroom, located at the other end of the house on the 1st floor, I can hear the sound of running water noise coming from the 2nd floor bath, kinda loud, I know 100% its not leaking, just making noise like water running through pipe, the walls are not up nor is the subfloor completely finished, What's going on if anything? and will the noise go away once the walls and floor are finished?

Casman,
Water rushing through the copper pipes resonates.
If the pipes are strapped tightly to the wood studs, there will be quite a lot of it.
Isolating vibration between the pipe and wood helps.
Packing the wall with insulation helps too.

I like to use 1-3/8" holes and use the plastic inserts that fit to the various size copper lines.
Of course, those of you using PEX will have a much easier time reducing noise in the water supply lines.
Terry