Ok so here's the deal, the house is 160 years old and has had its fair share of "craftsmen" that have tried their hand at restoration. The one thing I'm trying to figure out is the drain venting.
If you look in the picture you'll see a drain leg on the right that everything is tied into to. The main vent for that leg goes out about 4 feet and then heads up the corner of the original house (where I'm standing to take the picture).
The other leg on the left has the pipe coming out at and angle, which heads up the outer wall of the bathroom addition and then goes to the outside. Nothing drains into this leg.
So basically I have the one leg that everything goes to and then the other leg is just a vent.
To fix the half ass framing in that outer wall I would very much like to get rid of this additional vent. Anyone know why they may have added this extra leg?
The main drain is a 4". The additional one is a 3". There are two bathrooms (sink, toilet, tub in each), a washing machine and a wash tub hooked to the drain with everything on it.
Are there vents on any of the fixtures? Depending on how close they are to the main stack some could probably be stack vented but I can't imagine they all could. So maybe that extra vent is someone's poor attempt to correct poor drainage.