we are remodeling the basement in our 1923 bungalow, and currently, it is pretty much all ripped out. there has "always" been a 3/4 bath in the middle of the basment, and we are doing some work there. (this was someones past remodel, there is a rough floor patch over this area) I am currently trying to understand the plumbing that is there. The drain pipe for the upstairs bathroom comes through the joists about 10 feet away, runs horizontally until just behind the basement bath and then disappears into the floor. there are currently 3 pipes coming through the cement --the WC pipe, the shower drain and an AAC that the sink was plumbed into. On the other side of the basement (again about 10 feet, two 3 inch pipes enter the floor--one drains the kitchen sink and the other a utility sink that was there. Ok, heres the question. I can find vents for the upstairs bath, one goes through the attic just above the tub, and a second above the toilet. The two sinks are vented together on the other side. What I cant figure out is how the basment bath was vented. I suppose the shower and sink could both be on the AAC? But that cant be venting the WC could it? (Even supposing this job was not done correctly) Everything has always worked well. There are no longer any walls in the vicinity, but just next to where the waste pipe enters the floor is a brick stack. It is open to the roof, and once, I believe, served a stove on the main floor. There are "wings on it--the entire thing is about 4-5 feet wide. Is there any chance that a vent goes up that? I dont expect that the vent for the sinks could vent the toilet at all. We want to make all this correct, and need to understand what we have. Any ideas where else I can look?