Horizontal double wye question.

[DIYluke]

I would like to know if it's acceptable practice to use a double wye horizontally for drains.
I would like to use a 3" double wye, one of the branches would be the shower (bushed down to 2"), the other branch would be the wet vented w.c. (and two lav sinks beyond that), and the straight through fitting would be a clean out.
I was thinking the waste could get hung up on the ridge of the opposite branch instead of transitioning the 45° to shoot down the straight run like it's forced to on a regular wye.

I'm not just wondering about code, but also if it will cause headaches later. It's my house.

Thanks.

 

[Terry]

hj would say yes. I would say don't do it. If you do, have your level handy as the glue sets up very quickly.
You are much better off using wyes that you can angle to the proper grade. A wye directs pretty well.

 

[Sponsor]

 

[DIYluke]

I have the space to go a different route, i was just trying to use less fittings.
I can use a 3" wye in place of the double wye for the w.c./lavs and put a 2" wye into the back of the 3" wye for the shower. The clean out will go in the end of the 2" wye.
This way I can pitch both wyes up in opposite directions.

Was that your concern, not getting any pitch on the double wye?