in certain cases it can, what size is it, what is it currently venting and what will it be draining? Lazypup is teh expert who can tell you one way or another onc eyou give a little more detail.

thanks for the quick response!

It's a 3" straight iron pipe going from the stack to the roof.

It will be draining a toilet, shower (no tub) and sink.

If it matters, There is a 2" PVC drain pipe that is on the other side of the room that I could connect the shower to in order to keep that off of the vent pipe. (the previous owners used to have the washer/dryer on the 2nd floor. I capped the pipe, but left it, just in case...)

If one or more of the fixture arms from the fixtures on the ground floor are connected to that stack the answer is NO!

Code prohibits connecting a fixture arm to a vertical stack downstream of a watercloset, therefore if you attach a watercloset to the stack on the second floor you will need an auxiliary vent between the fixture trap and the stack on all the fixture arms on the ground floor.

lazypup,

Thanks for the response man! Much appreciated.

I've attached an image of my basement stack, to show you what i'm working with here. From what i'm seeing, None of the fixture arms are directly connected to the stack that would cause this to not meet code? I'm probably wrong, so I wanted your opinion.

Also, if using this vent pipe is not advisable or will not meet code, what would you suggest as the best possible method to achieve my goal here?

Thanks again,

jared

http://www.aww-kittah-aww.com/up/files/732/plumbing.jpg

Here is a link that might be useful: {{!gwi}}

lazypup,

followup question -

If I will still need a vent on the first floor, would something like a studor Mini-vent work? Where would I need to install this in order for it to work?

I have examined your photo in detail and find a number of issues that would be code prohibited today, however given that we have not installed oakum & lead joint cast iron in the last 40years it must be assumed that it is all original to the structure and that it did pass code at the time of installation therefore you are not obligated to upgrade it unless you make modifications to the fixtures or piping in the downstairs bathroom.

On the other hand, since the downstairs bathroom is venting off that stack you would not be permitted to discharge a watercloset into that stack on the second floor unless you first establish an auxiliary vent for the first floor bathroom. The problem here is that the line to the watercloset is a 4" line therefore it would require a 2" auxiliary vent.

thanks again Lazy!

After I get this 2nd bathroom installed, I'm planning on redoing the first floor bathroom, at which time I'll rip all of that out and do it right.

Last question:

Will there be any issues with cutting the stack below everything and installing a 3" Y then running that 3" straight to the 2nd floor?

hire a pro to cut the CI stack. you don't cut it, you snap it. if not supported properly(CI is allowed to self support so there may not be much else holding it) it could fall and kill you.

Oh, yeah. definitely. I wouldn't do that on my own.

The rest of the project I want to do on my own though.

I just want to make sure this will be a viable permanent solution before I start making the plans.

Thanks for the reply though, it definitely could be an issue.

just bumping this up.... Lazy, will my plan work? Will throwing a 3" waste pipe into the stack lower than the existing work and running that to the 2nd floor right next to the vent be a viable solution to all of this?

I wanted to get this rolling next week...

thanks again!

Running a second 3" parallel to the stack would be my recommendation however you will be required to establish a separate vent for the upstairs bathroom and that vent may not be tied into the existing stack.

If you can post a drawing or email one to me I will figure out the easiest solution for your new vent.

Also, I will need to know if you are under the IRC or the UPC