Hey All. Working on a reno in my basement. Had the basement dug down during the summer and the rough in for the new bathroom installed. There is a venting pipe beside the toilet that is currently capped. I'm unsure if this needs to be connected to something (main stack) or extended and vented to the outside? The contractor said it "just sits in the wall" but after reading about venting this doesn't sound correct. Any help would be much appreciated. Thanks