Flash-and-Batt Insulation Ratio for Zone 6
What is the proper ratio between high density spray foam and the batt/blow-in insulation in zone 6? This is for a 5/12 pitch cathedral ceiling using 16″ BCI rafters. From top down it would be roofing > roofing paper/peel & stick > 5/8″ OSB > high density spray foam > either batt or blown-in insulation > taped drywall > pine tongue-and-groove.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
R-25. See https://www.greenbuildingadvisor.com/article/flash-and-batt-insulation for details.