air barrier

[John Dirks Jr]

In warm climates it is said that the barrier should be on the exterior part of the perimeter walls. In colder climates it is said that the barrier should be on the interior part of the perimeter walls.

This is to keep the warm moist air from getting into the wall cavity.

What if the location is where the climate is split 50/50 heating vs cooling? Is it best to have no barrier at all?

[kurt]

Analyzing wall performance depends on large numbers of variables; trying to nail it down to a simplistic rule isn't really possible, although it's smart to keep the "rules" in mind.

I'm getting schooled as we type over @ JLC Forums about this very topic. I don't think there are hard and fast answers; lottsa variables about wind, water, and air screens, wall design, or other building materials/techniques that effect vapor transmission.

What kind of wall, orientation, weather patterns, materials, application practice, etc. all matter a lot.

[John Dirks Jr]

Yes I understand there are many variables. That's one of the reasons I decided to bring up the topic. My reading materials left me wondering a bit.

Lets us know when you gain any knowledge or opinions worth sharing.

[hausdok]

No air barriers used here. The few times where I've inspected homes where it was used, there was nasty stuff growing in the walls.

OT - OF!!!

M.

[InspectionConnection]

Here in this part of Canada, we have the sealed plastic vapor barrier on the inside of the exterior wall assemblies and building paper on the outside of the sheathing. I would say our climate is about 50/50 even though winter seems to last so much longer.