If you have ac on the inside and are managing humidity inside with air conditioning you should have a vapor barrier on the external wall surface. Directly under the siding.
High himidity outside. Cold inner surface creates a risk of condensation near the drywall surface.
In a heating climate you generally want the opposite. Vapor barrier on the inside surface directly under your drywall. Because the inside has the high humidity and the risk of condensation is highest near there outside cold surface.
deeptroller t1_iybe6yq wrote
Reply to I cannot find a straight answer anywhere: Do I need a vapor Barrier if I’m using rock wool insulation in North Alabama? by RedBeard972
If you have ac on the inside and are managing humidity inside with air conditioning you should have a vapor barrier on the external wall surface. Directly under the siding.
High himidity outside. Cold inner surface creates a risk of condensation near the drywall surface.
In a heating climate you generally want the opposite. Vapor barrier on the inside surface directly under your drywall. Because the inside has the high humidity and the risk of condensation is highest near there outside cold surface.