Rear outlet toilet rough in below washer

[rambelmont]

Can I rough in new sink/rear outlet toilet like this? or do I need to move the sink drain below the clean-out?
It would be easier to keep the washer drain above, but if needed, I could combine it with the new sink in a tee.
thanks

 

[Reach4]

DC uses IPC 2015. IPC requires that after a washer standpipe drainage joins with something else, that needs to be 3 inch. Maybe you could get a pass on that.

There is another problem, but first decide if that 3-inch thing would be a problem. That other problem is that the standpipe trap arm would need to connect to a sanitary tee, rather than a wye.

If that sink is an adjacent laundry sink, there is a different possibility that lets you use 2-inch for the combined of a standpipe and laundry sink load.

Or put in a laundry sink, and discharge the washer drain hose into that.

 

[Sponsor]

 

[wwhitney]

Not sure if I'm interpreting the picture correctly, let me know if this is correct: up is top of picture, large diameter is 3", upper wye is 3x2, and sink wye is 3x1-1/2. Arrow labeled 30" to toilet wall means the vertical discharge of the san-tee will turn horizontal and pick up the rear outlet WC 30" away. Not clear if the sink is a lav or a laundry sink.

As Reach4 mentioned, if that 3x2 wye is supposed to vent the laundry standpipe, it needs to be a 3x2 san-tee.

How is the WC being vented? The sink can only wet vent the WC if (a) it is a lav and (b) the laundry drain comes in downstream of the lav/WC junction, not between the lav and WC. So as shown, you'd need to separately vent the WC before it joins the sink/washer drain.

Cheers, Wayne

 

[rambelmont]

Appreciate your comments, Reach4 and Wayne.

Here are two options. Option A would be easier than Option B -- less demo. But both are possible.

I was hoping to use the stack as a wet vent for the WC. The only upstream item is the washer drain. The washer and the lav are vented elsewhere.

FYI, the sanitary tee for the washer is about 2-3 ft above the horizontal to the WC, rather than a few inches as the photo shows.

Thanks again
Bel

 

[wwhitney]

The vent path for the WC can not include any drainage from the washer. So the washer will need to tie in downstream of the WC, or you will need to pull a dry vent off the WC elsewhere before the WC joins the washer/lav.

If you separate the washer to come in downstream of the WC, it is likely you don't need the vent connection shown on the left of your last two pictures. The vent for the lav can be the vent for the WC. To be sure of this would require an overview of all the DWV plumbing in the area, not just the small portion in your pictures.

In your last picture, you can not use a san-tee on its back for drainage. It would need to be a combo.

Cheers, Wayne

 

[Reach4]

I think you are saying that the toilet is off to the right of the photos, and the lav is joining the toilet-only waste.

If that is the case, I like option A. I think the lav wet-vents the toilet. The washer standpipe is dry-vented.

 

[rambelmont]

Wayne,
Good catch --I was planning to use a long sweep not a sanitary tee for the washer drain, but did not have one on hand.

Is this Option C a better plan? It leaves the washer drain on the vertical - and I can connect the WC vent to it above the washer (blue line).

Right now, the horizontal connections are (left to right) stack - WC vent - cleanout - lav drain - WC.

I was thinking to rearrange: stack - cleanout - lav drain - WC vent - WC

Thanks again

Bel

 

[Mr tee]

Will that 3" clean-out be accessible? If not, it would be better on the 3" vertical above the washer.

 

[Reach4]

Is this Option C a better plan? It leaves the washer drain on the vertical - and I can connect the WC vent to it above the washer (blue line).

I don't think so.

 

[wwhitney]

I think I am still not understanding your label 30" to flange/wall behind toilet. Since the arrow is pointing to the left, all of my comments have assumed that the WC is downstream of the photo, to the left, as I mentioned in my first response. But now Reach4's interpretation makes more sense, that it is upstream to the right. [And that would be better communicated, I would say, by writing "WC" or "From WC" on the right end of the horizontal 3" pipe.] So please clarify.

If the WC is upstream to the right, then ignore all my previous comments. Option A is the way to go. The lav wet vents the WC. The washer can connect via a 2x1-1/2x2 san-tee (if such exists), as it only needs a 1-1/2" vent. No fixtures from above can drain down that vent.

But, if per Mr Tee's suggestion you move the cleanout to the vertical section, you want to maintain the 3" line vertically to the cleanout.

Cheers, Wayne

 

[rambelmont]

Thanks, guys -- I should have made it clear -- Reach4 is correct -- the WC is to the right.

And yes, Mr. tee, there is a large access panel in that location already, so I will keep the clean-out on the horizontal.

Option A is the easiest solution -- glad to hear it is the best.

And thanks, Wayne, for the warning -- the 3in stack is dry above the washer which is currently connected with a 3x3x2 sanitary I was hoping not to change. With Option A, I can keep it as is.

A bushing steps it down to 2in up to the roof. It is a strange space between two large HVAC trunks.
Thanks for all your help
Bel

 

[wwhitney]

May be advantageous to turn the cleanout 45 degrees towards horizontal for ease of use, depending on the size of your access panel.

Cheers, Wayne

 

[rambelmont]

Good thought