I'm renovating a 1960ish ranch in CT. The house was a simple two bed-one bath, I am redoing and changing the layout of the first bath and adding a full second bath (12ish feet away from original). The original plumbing was very simple: toilet right next to vent stack, stack directly above sewer line in basement, sink 3' away, etc.... here is my issue... it doesn't make sense for me to leave the main vent in the same location with the new layout, its in my way and none of the bath fixtures are conveniently located next to it anymore. so i've decided to vent each bath separately with its own 2" and 3" vent tied in properly to each fixture... my question is, do i still need the main stack? if i tie these new vents together in the attic and terminate through the roof like normal, why do i still need the old vent stack that served the original one bath layout?? maybe this is a stupid question... i've renovated several houses but dwv plumbing has always been my weakness. i simply cannot find any diagrams or examples online that are similar to what i am trying to do. the closest thing that i can find is a "circuit vented system", but that still always shows dumping into a main stack... thank you in advance for any help on this.