Oregon coast house build – GreenBuildingAdvisor

Hi all…I’m getting close to starting my build here on the south Oregon Coast and I’m down to figuring out which membranes to use. The roof: I have an unvented vaulted roof with (from inside to out): wood ceiling on 2x furring; Intello or Siga smart membrane; 2 x 12s with R-38C batts; 5/8” plywood sheathing, self-adhering WRB, 4” of rigid insulation (probably OC Foamular 250); another 5/8” plywood sheathing; roofing underlayment; aluminum standing seam roof. Walls: (from inside to out): 5/8” painted drywall; 2 x 6s with R-21 batts (OC pink stuff); 5/8” plywood sheathing; self-adhering WRB; 3-1/2” of Rockwool (2 staggered layers); 1 x furring; exterior cladding (either standing seam metal or a fiber cement panel). Given my 4C zone with humidity routinely 50% inside and 70-80% outside, I’m not sure how to think about perm ratings on the WRBs and what makes sense for the metal roof underlayment. Also, is the Intello necessary given the R-20 of exterior insulation on the roof? Would really appreciate some advice and smart thinking from this group. Thanks in advance!