Air barrier with foam insulation.
Just a quick question regarding technique. When building a wall using polyiso or closed cell polystyrene insulation on the exterior wall, where all joints will be taped, siding will be HardiPlank horizontal clapboard 4 inches to the weather: Am I incorrect in assuming that I will need an air barrier over the plywood sheathing before installing the foam sheathing?
After referring to the drawing in the details section, I do not see an air barrier indicated either under the foam insulation on the plywood sheathing, or at the exterior surface of the insulation.
Am I misunderstanding the detail? I thought that I would need to use a Typar or Tyvek air barrier on the surface of the plywood sheathing, and tape the joint laps. Then tape all of the joints on the foam prior to installing the furring strips. Can someone clarify this detail for me?
Thanks for the help.
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