DWV proper venting

Hello, I am installing a new bathroom with a tub, sink & water closet. I was not sure the best way to approch the venting. Two of my wall are load bearing and two are not. I wanted to make sure the vent size was enough to provide proper drainage. I also did not want to weaken the load bearing wall with over sized pipes. Take a look your advice is appreciated.

I am attaching a few pictures as examples.

Thanks

BBB

No load wall gif looks pretty good.

There should be a wye fitting going up to the lav, not a san tee. The right fitting would be a combo or a wye with a 45 to make it a tye-wye.

The line for the tub and lav would be a 2" line.
Going up to the lav, it could be reduced to 1.5"
And the tub can use a 1.5" trap.

https://terrylove.com/forums/attachment.php?attachmentid=698

Bath design 1

The bottom drawing is better, though the wye for the vent on the toilet should be turned the other way. The lav and tub vents can be 1.5", the toilet at least 2".
The tub waste line should be 2" until you vent it, and then the trap and trap arm can be 1.5"

The upper drawing is wrong.

Thank you

Terry said:

No load wall gif looks pretty good.

There should be a wye fitting going up to the lav, not a san tee. The right fitting would be a combo or a wye with a 45 to make it a tye-wye.

The line for the tub and lav would be a 2" line.
Going up to the lav, it could be reduced to 1.5"
And the tub can use a 1.5" trap.

Click to expand...

Thank you for your help!

BBB