Dry vent used as wet vent
I have a basement bathroom and an upstairs bathroom... speedball1 you stated in one of your questions answered
"Yes, but you must realize that once you drain the fixtures from the upstairs bath into it that it will no longer be a vent from that point down . It then becomes a stack and every fixture below,( the basement half bath), and will not be able to use this as a vent. They will have to be vented out the roof or revented back into a dry vent."
... my full bathroom upstairs uses the half bath in the basements vent... i've been living here for five years and i noticed that the basement half bath in basement is not revented back into a dry vent above the full bath upstairs... is this a major problem... the reason i want to know is that i'm thingking of adding an second floor bathroom and i already have this problem?. if i don't add another bathroom should i try to vent the half bath in the basement... i would have to demo a lot of tile that is already there that i really don't want to.