Drainage plane behind exterior Polyiso?

I’m getting ready to install 2″ exterior polyiso over OSB sheathing for my small addition.  I had not planned to install an additional drainage plane behind the polyiso, but this… I’m getting ready to install 2″ exterior polyiso over OSB sheathing for my small addition.  I had not planned to install an additional drainage plane behind the polyiso, but this…Read MoreGreenBuildingAdvisor