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RepWars Briefing - Questions & Answers
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Question...
"We live in the second floor of a three story condo. The soil lines are PVC. The are not insulated for noise. Does good practice indicate they should have been? Are there references that I can site to encourage the builder to correct the problem? I need any help I can get. "

RepWars Reply...
Noise originating from PVC drain piping is a well known nuisance in the plumbing industry. There have been many articles written concerning the causes and recommendations on how to avoid the problem. There is no national code requirement that forces the installer to insulate the piping to dampen any noise that may annoy someone. However, a builder that takes pride in doing quality work and considers the customer should be willing to do something about the problem. There is no legal dictate that I know of that forces a builder to provide facilities which exceed code requirements. However, a builder can be legally required to address this if the project specification includes a statement instructing the contractor to isolate all plumbing piping from the building's structural members in order to prevent the transmission of sound. Below is an excerpt from an article written in a national plumbing trade magazine which relates to your problem ...
"The last, and probably most meaningful factor to end users (to consider cast iron pipe above PVC pipe), is sound attenuation. Even though the light weight of PVC piping makes it easier to transport and install, it is the low density of PVC that makes it so poor at attenuating flow noise. Cast iron, on the other hand, is much quieter because its mass absorbs far more sound energy. You can always tell who has PVC piping installed in their home when someone flushes the upstairs toilet and it sounds like a rain storm inside the living room or kitchen wall. This is probably the greatest negative against PVC piping. Some of the noise can be muffled with wrap fiberglass insulation, but it doesn't compare to cast iron. The associated material and labor costs for insulating the piping only adds to the total cost of PVC. The noise problems associated with PVC piping are well known in the plumbing trade and most plumbers insist on installing cast-iron no-hub piping in areas of a home where noise would be an issue, such as when passing through living spaces on its way down to the basement. In other areas with short runs of horizontal drains, such as the toilet discharge or shower drain, noise isn't as much as an issue, since it is localized and intermittent. But if the drain pipe is directly above the ceiling of a living room, bedroom or other living space, cast iron should be considered." (PM Magazine, Oct."98)...
The following is a web page that also touches on the subject: http://www.cispi.org/internet/cispi/noise.htm


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