I'm looking to install a 1/2 bath on second floor (over the main bathroom) and wanting to run septic pipe from the second floor, but trying to reduce the noise. The pipe is going in to the wall of an old farm house (horse hair lath plaster). I would like to do it with as little demo as possible.

Thanks

I'm looking to install a 1/2 bath on second floor (over the main bathroom) and wanting to run septic pipe from the second floor, but trying to reduce the noise. The pipe is going in to the wall of an old farm house (horse hair lath plaster). I would like to do it with as little demo as possible.

Thanks
Hey Serge,
You wish to perform major surgery, which will include running a separate vent from the downstairs bath to the roof, if you plan on using the vent stack from the downstairs bath as a stack vent for the new bath upstairs, plus adding the sub floor drainage and you wish to do it with as little demo as possible? Lottsa luck! Ya do know there's going to be some noise when you flush and drain and the discharge falls down 15/20 feet into the basement main, don't you? Let me show you how the typical bath goes down, drainage wise. Most bathroom groups are roughed in like this.
Toilet connects to the stack vent. Lavatory connects to toilet drain and runs a vent off the top the stubout tee out the roof or revents back into a dry vent in the attic.. The toilet wet vents through the lavatory vent and the tub/shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes and also The Standard Plumbing Code Book in 90 percent of the country. Check your local codes.to make sure you're not in the excluded 10 percent.. The vent off the lavatory may be run out the roof or revented back into a dry vent in the attic.
While PVC is by far the most user friendly Cast Iron will be quieter. I still recommend using PVC. Good Luck, Tom

Lottsa luck! Ya do know there's going to be some noise when you flush and drain and the discharge falls down 15/20 feet into the basement main, don't you?
Yea, thanks :) Unfortunately, I was hoping for an easer solution, but I figured it was going to be a lot of dust and mess, and then the noise every time someone flushes. They just haven't come out with a quieter PVC yet.
Thanks