EXT and INT insulation in Zone 5 - GreenBuildingAdvisor
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Can you use both Exterior and interior insulation in zone 5 with out condensation concerns? Watched Asiri design video and he showed a wall assemby that one builder we talked […]
EXT and INT insulation in Zone 5 deb1221 | Posted in General Questions on March 22, 2026 01:16pm Can you use both Exterior and interior insulation in zone 5 with out condensation concerns? Watched Asiri design video and he showed a wall assemby that one builder we talked to uses. On video is said it could be a concern in cold climates but did not elaborate. Answer GBA Detail Library A collection of one thousand construction details organized by climate and house part Search and download construction details Join the leading community of building science experts Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field. Start free trial Related Questions Wall insulation for Zone 5 (Upstate NY) Metal roof over polyiso, conditioned attic in Zone 5 Foil faced polyiso (R 13) on exterior in Zone 5 Ice and water roof membrane in Zone 5 Replies AndyBower | Mar 22, 2026 02:14pm | #1 The main considerations for the use of exterior and interior insulation combined are: - the ratio of R-values for the exterior and interior insulation - the vapor permeance of both - the use of an interior vapor and air control layer The ratio of R-values for exterior vs interior insulation is used to evaluate if the assembly will sufficiently reduce condensation risk at the interior surface of the exterior sheathing, for a given set of interior and exterior temperature and humidity conditions. The colder the exterior temps and th...
