I am finishing the work from a plumber I hired who disappeared. Besides the point really but now I am trying to move this forward until I can find a new plumber to help finish this workshop. I am trying to figure out the venting system and have attached a crude picture of what I am considering doing. The main question is, Can I tie into the main vent stack for the upstairs bath or will that be considered wet venting? What I have drawn out connects the upstairs to the aux drain (far left) and then ties the vent from this stack to the main vent. Happy to explain further so ask away with more specifics if that would help. I am fine with the details in each bathroom, just the venting is a little confusing to me.