Does a Wall in South Carolina Need a Vapor Barrier?
Most walls in South Carolina fall under a code exception that removes the requirement for an interior vapor retarder.
Does a Wall in Saskatchewan Need a Vapour Barrier?
Yes. Saskatchewan falls under the National Building Code of Canada, and that code requires a vapour barrier in every insulated wall assembly, regardless…
Does a Wall in Rhode Island Need a Vapor Barrier?
Rhode Island sits entirely in IECC climate zone 5A, with no county carved out into a different zone.
Does a Wall in Quebec Need a Vapour Barrier?
Yes. Quebec follows the National Building Code of Canada, and Part 9, Article 9.25.4 requires a vapour barrier in insulated wall assemblies, full stop.
Does a Wall in Prince Edward Island Need a Vapour Barrier?
Yes. Under the National Building Code of Canada, every insulated wall assembly in Prince Edward Island requires a vapour barrier, and the province…
Does a Wall in Pennsylvania Need a Vapor Barrier?
Yes, Pennsylvania requires an interior vapor retarder on framed walls, and the reason is simpler than the code language suggests: the entire state sits…
Does a Wall in Oregon Need a Vapor Barrier?
In Oregon, the answer splits with the state itself. Eighteen counties sit in IECC climate zone 5B, where the 2021 International Residential Code requires…
Does a Wall in Ontario Need a Vapour Barrier?
Yes. Under the National Building Code of Canada, Part 9, an insulated wall assembly needs a vapour barrier, and the requirement carries no climate-zone…
Does a Wall in Oklahoma Need a Vapor Barrier?
The answer splits three ways across Oklahoma’s 77 counties. In the 59 counties mapped to Climate Zone 3A, the 2021 International Residential Code does…
Does a Wall in Ohio Need a Vapor Barrier?
Yes. Under the 2021 International Residential Code, a frame wall in Ohio needs an interior vapor retarder.