Cast iron pipe with galvanized metal branches. So I replaced the drain line that was leaking. There is a vent line where the metal tee is mounted halfway into the floor. I will have to cut the floor to connect into the vent line. Very confined space to work in.
I ran the drain and everything is working fine without the vent. The vent ties into a main stack about 4 feet from the floor. If I was to just cap the vent below the floor it would fill with sewage if their was ever a blockage. Is this a horrible thing.