Drain for double sink vanity

[Doublebonus]

Converting single sink to double. Existing stubout is in center. Converting from copper to PVC. All drains and vent stack are 1 1/2 inch.
Can I use the bottom drawing? Would tie in to existing copper stack at top and bottom with shielded coupling. Everything between ferncos would be PVC. Would it be ok to use a reducer bushing in bottom 2 inch side of double fixture fitting to allow 1 1/2 inch from floor to connect.

Having trouble posting photo.
I have a 1 1/2 copper from floor straight up to to stubout,straight to roof vent. In double fixture fitting would need to use adapter bushing in bottom 2 inch opening of double fixture to accommidate 1 1/2 inch pipe from floor, 2 1 1/2 inch arms to stubs and 1 1/2 inch continues to roof.

 

[Jeff H Young]

no its definately not ok to bush down the fitting will it work ? yes . is it right ? no.
You could stack 2, 1/1/2 santees and revent the bottom one or add a aav to it a bit hokey but you cant wet vent them verticaly unless you have 2 inch. Im thinking stacking the 1 1/2" santees would work fine on a lav, but its not legal and I wouldnt do it at least not in my code

 

[Sponsor]

 

[Doublebonus]

Then there's no option that would meet code.
Terry gave an option a while back that I'm going to have to go with.
He said to have a wye at top and bottom with basically 2 vertical stacks side by side,each one having a sanitary tee for horizontal waste arm.
Wye at top and bottom would tie into existing stack.

 

[wwhitney]

He said to have a wye at top and bottom with basically 2 vertical stacks side by side,each one having a sanitary tee for horizontal waste arm.
Wye at top and bottom would tie into existing stack.

That works fine (and even for the UPC if the 1-1/2" stack enlarges to 2" before or as it turns horizontal, which may not be very likely).

The IPC will let you just stack two san-tees for the two lavs, all on a 1-1/2" stack, as a sort of vertical wet vent. But it calls it "common venting at different levels."

Chapter 9: Vents, Ohio Plumbing Code 2017 | UpCodes

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Cheers, Wayne

 

[Doublebonus]

The link that Terry suggested. He said to use the one in green. Seems there is no other option. If I stack 2 tees the stubouts would be at different levels?

Convert single sink to double

New here so bear with me. My daughter wants a double sink vanity,and since I'm her diy plumber! All drains are 1 - 1/2 ". It will be centered over existing stubout. It may not be up to code but I have little options. Can't repipe entire drain due to it extending into adjacent finished part of...

terrylove.com

 

[wwhitney]

If I stack 2 tees the stubouts would be at different levels?

Sure, but that's not a problem per se. The lav tailpieces can be different lengths. If you use a street 1-1/2" san-tee into a regular 1-1/2" san-tee, the height difference would be about 3-1/2".

But the green option is fine if you prefer that, and it avoids this height difference.

Cheers, Wayne

 

[wwhitney]

One unusual option the IPC allows is "common venting at the same level" where you would use a single san-tee off to one side of both lavs, and then a common trap arm that extends to the far lav. The near lav's trap arm would join the combo trap arm with a horizontal combo.

The far lav's trap arm would have to comply with the total fall limit (1-1/2" for a 1-1/2" trap arm) and resulting length limit (6' if you pitch the trap arm perfectly at 1/4" per foot). Well, both trap arms would have to, but unless you do something weird upstream of the combo, if the far lav complies, the near lav would, too.

Cheers, Wayne

 

[Jeff H Young]

The link that Terry suggested. He said to use the one in green. Seems there is no other option. If I stack 2 tees the stubouts would be at different levels?

Convert single sink to double

New here so bear with me. My daughter wants a double sink vanity,and since I'm her diy plumber! All drains are 1 - 1/2 ". It will be centered over existing stubout. It may not be up to code but I have little options. Can't repipe entire drain due to it extending into adjacent finished part of...

terrylove.com

as wayne pointed out ohio code will allow stacking those santees your code is easier than ours in most ways but I see no harm in going with whats legal for you . We stack santees commonly like that all the time just not 1 1/2 size. like when we have double lavs and one has got a condensate going to a wye branch tailpiece under the lav