This problem is all too common;
You need to insulate the pipes themselves for two sound reasons: 1. water running and 2. vibration. for this you should wrap the pipe with specialized pipe soundproofing wrap, even the vent. the problem presents if pipe was left too close to GWB, then it gets compressed or it is just not possible to wrap all around.
The second layer should be insulating the partitions between rooms with battens, lets say if pipes are in the bathroom, all around the bathroom, so sound transmission is reduced.
finally, spray foam can be used to fill gaps, like between door frame and rough opening. also around electrical boxes, faucets, etc.
BTW, you also need to insulate supply lines. probably more important.
Sound travels easily through metal; actually through drywall screws, through metal studs and finally to screw on other side. isolating metal to metal connections is very important. use plastic clamps against metal, but in the end a partition with a lot of plumbing should in addition be double, where studs, if metal, are staggered so they do not touch, as in a party wall. or perhaps a box chase can be built around the offending pipe.
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Ivan Contreras, LEED AP, AIA
Qualifier | Director
CONTRERAS MUNOZ & CO
Miami FL
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Original Message:
Sent: 04-07-2020 17:26
From: Michael Blaes
Subject: Sound insulating PVC plumbing
What is the consensus on the best way to sound insulate existing PVC DWV pipes in walls and ceilings? Spray foam, pipe sound insulation and mineral wool are being investigated for a client.
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Michael Blaes AIA
Principal
Michael E. Blaes, AIA
Webster Groves MO
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