We’re at the inspection and I ask my client to stand near a downstairs wall that I suspect holds the waste line for an upstairs toilet. Before heading upstairs I asked her to listen for sounds of rushing water.
I hear a few comments from the downstairs “listener” (and they’re not good comments). Evidently, she could hear the event and it must have been in stereo.
At this stage, there is no easy answer to this dilemma. Here’s how I have handled it in the past and the issue is much easier to solve at the building planning stage or at least during construction. Run the 3 inch Schedule 40 PVC waste line in a sleeve. During construction thread the smaller pipe through a larger pipe, for instance, a piece of 6″ inch PVC. The air space between the two pieces of pipe will deaden the sound. Now keep in mind, that means there has to be room for the pipe (i.e. 6″ stud wall), at least in the area where the pipe is stubbed through the floor.
Other ideas are to inset two layers of drywall “in between” the studs of the wall cavity where the pipe is located. It also helps if the pipe doesn’t rest against the wall framing…anywhere. If the framed wall touches the pipe, the vibration is quickly picked up by the wood and is amplified.
Or, if you can talk the plumber into purchasing a section of cast iron drain, use it on the vertical stand of pipe. Cast iron does a much better job of insulating the sound of rushing water.
Comments? Other ideas?
How would you keep a vertical waste line from sounding like the Atlantic Ocean coming ashore?