I am building a 3 piece bathroom + laundry in this old basement laundry room. The cast iron sink pictured drains to the floor and that vertical 1 1/4" copper pipe is a wet vent, I believe, as it is tied into that main 4" stack going across the ceiling.
Basically I'm wondering if I can tie any or all or these fixtures to this wet vent? I'm not expecting any good news as it's a 1 1/4" pipe that is tied in currently but if I could that would be awesome. I'm in Toronto Ontario Canada.
If it is, in fact, a wet vent, it's not good for much at 1-1/4" (minimum size wet vent is 1-1/2" and that's only good for 1 DFU.)
If it's a dry vent, it's more useful. Up to 42 DFUs with a 2-1/2" drain.
And it is probably a dry vent, unless there's a sink above tied into it as a drain.
Assuming your applicable code is similar to IPC there's a likely problem in that you can't vent a drain bigger than 2-1/2" with a 1-1/4" vent. And a "three piece bathroom" includes one fixture that usually needs 3" minimum drain pipe.
