I have a 3rd floor condo, we are the top floor. We want to move our kitchen sink about 2 feet. The drain comes from the floor below through a 2.5" concrete topper in the floor. The vent goes vertically up to the ceiling and outside at the roof.

The challenge is moving both the drain and vent. The vent was gng up through a wall but we want to remove that wall so it means rerouting the vent. The drain seems that it would need to be rerouted by chipping up the concrete topper and turn it 90 degrees.

Is this a practical job?

Thanks!

What country do you live in... in the USA those pipes and walls are owned by the condominium and would have to have their permission to do anything and since walls effect all tenants it would have to be performed by licensed, and insured contractors.

I suspect you are outside the USA however.

I'm in Canada.

in the USA those pipes and walls are owned by the condominium and would have to have their permission to do anything That's half right. On the Gulf Coast we are "condo center". A condo owner's allowed to make changes to their unit if.
1. They don't impact their neighbors and,
2. The work remains in the confines of the unit and doesn't encroach in "The Common Area". Having said that, chipping up the floor, (which is the downstairs units ceiling) and tearing out walls should be passed by the association before starting any work.
In place of the 90 on the drain 2 45's or a short sweep would be better and, if code allows, you could install a AAV( air admittance vent, see image) in place of running a vent through the roof. Good luck, Tom

I'm the original poster. The problem is not really getting permission because I have passed all of this in front of the condo association already and we have permission to do the work.

The real question is more technical in nature in terms of the difficulty of the task. The existing vent pipe appears to serve our unit (3rd and top floor)as well as the two units immediately below us on floors 1 and 2. Seems we are at the top of the sanitary riser and then we tie into the venting system to the roof. So I don't think we could use an AAV as this would essentially be putting our downstairs neighbors on an AAV which they haven't signed up for :-)

We could re-route the vent pipe to account for the wall we are removing. Is there a limitation on the length of the vent pipe after the drain? As for moving the drain itself, the concrete topper is 2.5" on top of a 5/8 sheathing, and then the floor joists. The joists run perpendicular to where we can to move the drain 2 feet away. So I'm not sure we can fit the drain pipe on top of the joists and still finish the floor so that it can be tiled on top.

Any suggestions appreciated.

I understand your problem.
Is there a limitation on the length of the vent pipe after the drain?
On a 2" trap to vent some codes allow 5' While my code allows 6'.

I'm not sure we can fit the drain pipe on top of the joists and still finish the floor so that it can be tiled on top.
Can you notch the joists a little to allow the pipe to fit?
The nice thing about a vent is that you can put as many bends and 90's as you wish as long as you maintain slop back to the fixtures it's venting. More questions? I'm as close as a click. Good luck, Tom

Thamks Tom,

I'm attaching some photos. One is of the work site with the walls removed. We want to move the sink about 2 feet closer to the camera. The vent goes to the ceiling and them turns left. Not sure where it goes from there, but ties to the roof eventually.

Other photos show the plumbing diagrams. Shows a 1 1/2" drain which hooks into a 2" drain to go to the unit below and connections to 1 1/2" vent to the roof.

Thanks a lot!

Paul

Thanks for the picture and drawings. I've printed them out and I'll study them tonight and get back to you in the morning. Good night, Tom

Hi Paul

Tom asked me to look into this as he is having a little trouble seeing things as perfectly as he usually does, so thought I would post my thoughts, OK?

First real issue I see is installing the 2" DWV copper 90 on the vertical stack to turn the stack toward the camera as you indicated...this 90 needs to be sweat (soldered), so a pretty large hole would need to be opened in the floor to actually get the bottom half of the 90 below the floor so that the top half of the 90 sits on the floor.

Other issue is that the pipe will be flat under the concrete topper, but only 2 feet or so, so I don't see that as a major issue.

Otherwise, I don't see any issues here that should stop you from proceeding forward. As long as the pipe is under the concrete topper then flooring shouldn't be an issue. Connect back onto the vent that exists in the ceiling.

Install full size 2" cleanout under the sink.

Should do it.

Questions? Let us know...

Mark

Any possibility of getting permission of your neighbor down stairs to do the work through his ceiling. Be well worth assurances that the ceiling repairs would be invisible and a nice dinner for two. Plumbing could be done in a couple hours. Ceiling repairs and repainting would be easy but would span a couple of days.