Prioritize R-value or permeability when choosing exterior foam board (when there’s a poly vapor barrier inside)?

Hi folks,I’m hoping someone might be able to offer some advice on a weird dilemma. When we replace our siding, we’re installing 2″ of foil-faced polyiso on most of our… Hi folks,I’m hoping someone might be able to offer some advice on a weird dilemma. When we replace our siding, we’re installing 2″ of foil-faced polyiso on most of our…Read MoreGreenBuildingAdvisor