I am designing a DWV for a 2 story remodel (with the aid of a retired plumber). The second story toilet is stacked over the first floor.
My question is: Does the first floor toilet need a separate vent that will tie into the 3 inch vent above the second story toilet or can it use the drain from the second story toilet (ie went vent). All the articles I have seen always show a simple single toilet installation.
Other notes: west second story wet wall contains a toilet and sink
west first story wet wall contains a toilet and shower