I have a question concerning the installation of a washer, dryer and laundry sink in an old (1940s I believe) house. On the other side of the wall they will be installed against is a bathroom, with an old clawfoot tub directly against the wall and a sink and toilet further into the room. The reason I mention this is I would like to avoid running new plumbing all the way from the basement (this is on the second floor) and would like to make use of the plumbing from the tub if possible, as the tub is no longer in use. I am reasonably handy with a wrench and don't mind the elbow grease but I want to be sure I get it right the first time.
My concerns are drain size and vent positioning. I learned recently that code requires drains for washing machines to be 3". I don't have a 3" drain line anywhere close, so I thought I would also install a laundry sink and drain the washer into that, which is permissible by code. The laundry sink would only need a 2" drain. Can I borrow the drain from the (unused) tub for this purpose? I know there needs to be a vent in there too, any suggestions on where that would go?
Here is a picture for reference, in full MS Paint glory:
I am assuming there won't be any code issues tapping into the tub's hot/cold lines for the washer and sink. Anyone is welcome to fill in the missing plumbing between the laundry sink and tub. all advice and suggestions welcome! thanks!