Originally Posted by Just Bill
Sewer vents are supposed to extend to or above the rooftop. Could it be this is just not finished yet??? Vent caps usually fit over the pipe, not inside, so if it is flush, not sure how you would connect one. Maybe add an extension.
There are two other vents that do go to the roof. The house is 80+ years old. I am sure that at one time (up until about 10 years ago), this pipe did connect to the sewer in the basement bathroom. I also recall a similar pipe in the house I lived in as a child. It was a large pipe that came straight out of the concrete floor next to the main trap (in the floor) and went through the foundation.
At this point, since the vent is no longer used, I may just slap some concrete into it from the outside. I would prefer to use a removable device though, in case I decide to use this pipe as the vent from a fan I would like to install.
I think I'll take a look at the Home Depot plumbing aisles and see if I can find something.
Found what I was looking for. A 4" drain cover, plastic. It just fits into the pipe, doesn't sit flush with the foundation, but good enough.
When I installed, I first opened the inside end of the pipe (was just a rubber cap over it) because I suspected that I might find some dead animal inside, or at least bugs and junk.
Sure enough, I found a dead bird. Had been dead a long time. Probably an injured that went in there to die. We have some cats in the neighborhood.
The cover will prevent another animal from dying in there, and is still easily removable if I decide to install a fan.