Using Combination Wye to Vertically Connect to Main Waste Line

[Damon-D]

Hello,

We are trying to connect a "P" trap to the main waste line. and maintain max. 24” between the fixture outlet and connection to the “P” traps.
My modeler, has introduced combination wyes to make up the elevation difference between the horizontal pipe extension from the "P" trap and the main waste line. Is this acceptable?
Please see attached image.

Any feedback will be highly appreciated.

Thanks you!

 

[ReelPlumber]

There is nothing wrong with using combo's. The problem is rolling up off the main. This breaks the vent off your system and now requires an additional vent on each branch that rolls up off the main.

I have never really understood the 24" drop rule when your allowed 48 on a washing machine.

 

[Damon-D]

@ReelPlumber thanks for your feedback.
What would be the best constructible solution? Go slightly over 24" max. for the extension and avoid the combos and the need for vent on each branch?

 

[frodo]

 

[CT18]

I am doing the same thing on a project and the inspector lets me jump as long as my run to the trap does not exceed 8'. We oversized the main and the runs. We have 8" main and 6" over to the floor drains.

 

[ReelPlumber]

@ReelPlumber thanks for your feedback.
What would be the best constructible solution? Go slightly over 24" max. for the extension and avoid the combos and the need for vent on each branch?

What's the distance from where your sanitary exits the building to the farthest fixture?

 

[Twowaxhack]

I am doing the same thing on a project and the inspector lets me jump as long as my run to the trap does not exceed 8'. We oversized the main and the runs. We have 8" main and 6" over to the floor drains.

Basically a combination waste and vent system