Basement toilet help

Hi. New to the forums and to plumbing. Willing to learn.

I recently had my septic tank removed and got connected to the public sewer. Waste goes underneath my footing to a 6" pipe that runs to the street.

When the plumber connected my old system to the 6" pipe coming under the footing into my basement, I told him that I'd want to add a basement bathroom in the future. That bathroom will be behind the wall on the left in this picture:



My plan is to put the toilet so the back of it is perpendicular with the foundation wall. In the picture that would be about where the brown bucket is, but on the other side of the wall.

What he left me with was a 6" threaded, capped opening that points toward the middle of the house. When I tried to expose it I ran into water, but the best picture I could get of it is here:



The fact that the opening faces away from where I want the toilet to go confuses me a little bit. I'm looking for suggestions on how to get from there to the toilet and where to pick up the sink drain.

I also considered connecting the drain to the vertical member in the 2 pictures below, but that appears to leave me slightly too high to get a 90 degree turn up and a toilet flange flush with the concrete. Am I right about that?





Any advice would be greatly appreciated.

You can take out more concrete, and add a fitting in the ground, a wye fitting. You will also need a wye fitting for the 2" vent that goes through the roof.

Terry said:

You can take out more concrete, and add a fitting in the ground, a wye fitting. You will also need a wye fitting for the 2" vent that goes through the roof.

Click to expand...

Thanks for the response. Do you mean take more concrete out towards the foundation wall, and put a 6" wye in underneath that? It'll be hard to get under there because I have a drain system inside (1st picture) that runs along the wall.

I was told that I didn't need any additional venting, is that wrong?

I was told that I didn't need any additional venting, is that wrong?

Click to expand...

If it serves a toilet, then yes you need a vent.
I would go ahead and pick up a plumbing permit locally, and then the plumbing inspector that help guide you as to what he will expect.

In the United States of America, we have rules and regulations on plumbing, electrical and buildings.

All plumbing requires permits and inspections.
All plumbing fixtures require venting.
Fittings below grade require waste fittings, those are wyes.
The toilet will need to be vented within six feet of the closet flange.

The pipe in the picture is not 6", it looks to be either 3" or 4"

Terry said:

If it serves a toilet, then yes you need a vent.
I would go ahead and pick up a plumbing permit locally, and then the plumbing inspector that help guide you as to what he will expect.

In the United States of America, we have rules and regulations on plumbing, electrical and buildings.

All plumbing requires permits and inspections.
All plumbing fixtures require venting.
Fittings below grade require waste fittings, those are wyes.
The toilet will need to be vented within six feet of the closet flange.

The pipe in the picture is not 6", it looks to be either 3" or 4"

Click to expand...

Thanks, I hadn't thought about using the inspector as a resource for instruction. The pipe that runs horizontal and exits to the outside I'm fairly sure is 6". I recall the plumber remarking that I was lucky to have that. It is barely visible in the 2nd picture because it is almost entirely under water.

Waste is specified by ID, not OD. It would be odd to have a 6" line...a 4" line would be about 4.5" OD if it's PVC, more maybe if cast iron but not a huge amount more (unlikely, but possible).

A drain line can't (normally) be used as a vent. A drain line, if you go above the highest thing draining into it continues up AS the vent, but below anything feeding into it, it is no longer a vent.

Here many of the lines increase to 6" a few feet outside of the foundation.

Thanks for all the responses. I've learned a lot already.

I'm considering two options at this point.

Option 1 would be to wait until late spring until things dry out and add a wye closer to the footing. From there I'll need to connect to a vent with a 2nd, 2" wye, and then to my toilet and sink. (The vent part of this seems really really hard.)

Option 2 would be to raise the cleanout slightly and connect a T just above grade. From the T I can attach the wye for the vent and then to a back outlet toilet and sink.

Am I on the right track with either of those?