Hi, I'm in the process of finishing my basement and I have a plumbing question.

As you can see in the attached image we have a drain for our kitchen sink and dishwasher in an island cabinet in the above floor draining to a 3" pipe in the middle of the basement. I'd like to reroute this to an existing 3" drain currently servicing a laundry room and 3 piece bathroom (the drain in the foreground).

I'd like to run the kitchen drain and the vent through the floor joists and attach the vent to the drain line just prior to tying in with the existing bathroom/laundry room vent. This way I'd have less to box-in in the middle of the room.

The horizontal span of the reroute would be 10 feet and I'd place in between the floor joints so I can attach drywall on the floor joists.

I'd then cap off the drain in the middle of the room and cement over it flush. I imagine this process would involve taking out enough cement to put a cap on and cover with cement.

I'm not sure what kind of subfloor I'm putting in yet, but if it's raised at all I imagine I can just cap of the drain without breaking concrete.

All the vent and drain lines in the picture are 1 and 1/2 inch or 3 inch.

Is there any concerns with what I'm describing?

Thanks in advance!

Ummmmm...

First things first;

Why is the trap for the kitchen sink below the floor?

Quote:

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Originally Posted by iamgrowler

Ummmmm....

First things first;

Why is the trap for the kitchen sink below the floor?

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Hehe, good question. I assume it's fine as my house was just built and past inspections.

Yeah, Mercer Island, WA has a few inspectors like that as well.

As the owner's rep (basically a go-between between the homeowner and the general contractor) I had to explain to the Inspector, using the UPC's Illustrated Training Code Book no less, why he shouldn't sign off the job he was inspecting.

I didn't make very many lasting friendships on that job, by the way.

Could you do me a favor and post a close-up of the fittings used to transition the vent and trap arm?

As for re-routing the waste line to the other stack, I don't see that as being a problem.

Although there are way's of redoing this so that much of the run will be properly sized and in the joist bay instead of hanging below the ceiling line.

Hi I've attached a close up and a picture of the under cabinet above. It looks like there is a cleanout there, but no trap. The trap below the floor is glued - though you can't see it very well in the picture.

I was thinking of reusing the trap but moving it as close to the floor as possible in the joist bay. Run 10 foot lengths for the drain and the vent and join under the joists near the other stack I want to tie into.

Or since I need to box in the beam and hvac in any case, perhaps I can loop the vent under the joist and over the over the beam (or vice versa for the drain) and then tie in the drain from the top and run one 10' length to tie into the other stack. I'd be concerned with joints this way though, as it would be acting as a large trap (I'm not sure if this is an issue with vents though).

My main goal is to get the vertical stack in the middle of the room out of there, not so much concerned with any boxing in on the ceiling.

I'm in Ontario, Canada by the way.

Thanks again.

Yikes!!

I don't have a copy of the 2005 National Plumbing Code of Canada handy, so I can't say what is or is not acceptable in your province -- But this certainly wouldn't fly in the lower 48.

But that really is beside the point, it's signed off and that is what really matters.

I say re-route the drain to the other 3" stack -- As you're doing this, bear in mind that you will need to be able to push the stack up at least an 1-1/2" (more like an 1-3/4") after it's cut to accomodate gluing in the new fitting.

If this isn't an option, you can also use a CP-33 shielded coupling manufactured by Mission, Fernco or Pro-Flex and a short piece of 3"ABS pipe.