Noisy Plumbing

[tedkitch]

One of the bathrooms has very noisy pipes. I'm not sure how to explain it, but in one of our bathrooms whenever someone uses the bathtub (or shower) you can hear the water flowing through the pipes in the next bedroom. It can be very load. Now this isn't like hammering or banging, I'm talking about the sound of the water flowing through the pipes.

What can I do to debug the source of this noise, what are the possible causes and what do I do to fix it? None of the other bathrooms have this problem, only this one bathroom and the noise isn't like then when the sink or toilet is used in this bathroom. I thought that it might be the showerhead, but the noise is just as bad when the water is running to the tub before it goes up to the shower head.

Any help would be greatly appreciated.

TIA,

[Uncle Cracker]

The type of noise you describe is usually caused by water flowing too fast through undersized piping or a restriction of some sort, such as a pinched pipe, 90-degree fitting or a partially closed shutoff or flush valve. Pressure control devices and backflow preventers can also make noise, because they actually cause a flow restriction in order to work properly, but you won't have any of these inside your walls.

As to a quick fix, about all you can do is make sure all your shutoffs are open fully. If the problem persists, try to determine which device is/are in use when the noise happens. Then you may get some clues what to do next. As a last resort, you can try re-piping the section where the noise is heard with a larger size of pipe (or even making a parallel run to split the "load", and keep the noisy section in service). Larger pipe means lower velocity at a given flow, while an extra pipe means less flow through the original. Either should eliminate the noise.

[crokett]

Is the noise from water running through the supply pipe or water running through the drain?

[mikel]

I know plastic waste pipe can be way loud...

I have open walls and wrapped the pipe with rug underlayment or sound insulation.

...mikel

[JimD]

Only significant improvements I can think of are to reroute the pipe away from your bedroom or to replace the stright run near your bedroom with cast iron. They make rubber joints to facilitate putting cast iron and plastic together.

Jim

[Uncle Cracker]

Please note that my suggestions are based on the noise being in a supply pipe. Gravity drain piping is a different animal entirely...