Air Permeable and no vapor retarder?

So I’m building a Tiny House with a Hybrid unvented roof and wall assembly.   Several inches of foam board on the exterior of plywood sheathing.  Looking at the hybrid assemblies… So I’m building a Tiny House with a Hybrid unvented roof and wall assembly.   Several inches of foam board on the exterior of plywood sheathing.  Looking at the hybrid assemblies…Read MoreGreenBuildingAdvisor