I am remodeling my 1970's bathroom and would like to add an additional sink. Venting may be an issue. The existing sink is very close to the main stack and doesn't have a vent loop (I think if it's real close to the main stack it doesn't need it?). So, for the second sink can I use a AAV (air admittance valve) on the second sink for additional venting?
BTW the bathroom is completely gutted to the studs. The studs are 2x3 studs for the interior walls not 2x4.