Yet another vent question

[Tod B Schmidt]

Sorry, I am new-ish to plumbing and have a pretty basic question. I am sure it has been asked before, but adding a half bath above the main stack in the basement and a question as far as vent location.

Is the dry vent in red shown in the right place? Or should it be on the other side of the WC to protect the lav vent? What else is wrong with this picture?

 

[Terry]

The lav run with 2" can wet vent a toilet. Regardless, the lav needs a vent.
The best way to do that is to use a 3x2 wye for the lav off of the run for the toilet, which ends in a 90 looking up.

 

[Sponsor]

 

[wwhitney]

Regardless, the lav needs a vent.

And just to expand on that a bit, the lav trap needs a vent, and that vent has to come off the lav drain before it falls more than one pipe diameter from the trap outlet. So you need to have a vent takeoff at an elevation above the floor, since the lav trap is above the floor.

Cheers, Wayne

 

[Tod B Schmidt]

Thanks for the replies, I think I understand my options now. I was hoping to avoid going straight up from the lav since I have to traverse joists to get to where I go to the attic to tie into existing vent.