Great question, and the short answer is no,wood panels would not change the placement of the vapour barrier in the wall assembly. But why leave a short answer when you can get all wordy about something?
Thanks so much for all this information. We live in southern Vancouver Island. We definitely want to avoid using 6 mil poly anywhere in our home. We are wondering if vapour barrier paint would be acceptable to the local building inspector (just trying to do research before we approach him) but would want a paint that is not toxic. We will also be doing T and G for the ceiling and ultimately it will be painted to better show off the ridge beam and half scissor trusses but we read in one of your links that vapour barrier paint is more applicable for walls so not sure what to do for the ceiling (roof is metal). Any other thoughts you have are greatly appreciated.
6 mil poly barriers are actually not as a big a problem with ceilings, the vapor drive isn't quite as problematic as with walls. In the Edelweiss Demo House we used vapour barrier paint on the walls but we used poly on the ceiling. As for your building inspector, that could go either way, so if you want to try vapour barrier paint (or vapour retarder primer) check with an inspector ahead of time. As for the toxicity, We used Benjamin Moore vapor barrier paint which was low VOC but not Zero VOC unfortunatetly.
The honest answer is that from a scientific point of view, painted wood will actually act as a vapour barrier, meaning vapour will move through it so slowly that it would qualify as a vapour barrier, but it is highly unlikely youll find a building inspector to accept that for new home construction. And I say that with the caveat that you should not even consider that if you don't have a proper air barrier in some other form. Be sure to read this page aboutthe difference between Air Barriers and Vapour Barriers因为它们经常组合在一个产品中，但执行完全不同的任务。
3/4 inch OSB sheathing on the interior can be an excellent air barrier and a great vapour barrier as well. There has been a steady evolution in the way we build homes over the…
Wood ceilings are a beautiful natural material with no off-gassing and no treatment necessary so why do we systematically choose drywall. Wood ceilings - what's the the…
Can a house be too airtight? No it cannot. The difference between air barriers and vapour barriers is often confused. Also confused, is which one is more important. The…
Drywall may all look the same sitting in stacks in the store but they are very different in performance, strength and ecological impact. How to Choose Eco-Friendly…
Vapor retarder latex based primers can be twice as effective as the requirements laid out in many building codes regarding vapor barriers requirements. Vapor Barriers in walls…
Hi Sue,
Great question, and the short answer is no,wood panels would not change the placement of the vapour barrier in the wall assembly. But why leave a short answer when you can get all wordy about something?
石膏板的替代品，如舌槽木或室内胶合板墙不会对蒸汽屏障(或“蒸汽”屏障，取决于你的国家)的理想位置产生任何影响，因为从石膏板到木材的R值几乎没有变化。And further to that,wood can act as an air and vapor barrier in some cases因此，带有饰面涂层的胶合板作为防蒸汽屏障也可能是相当不透水的，但由于它将与普通的6毫米聚防蒸汽屏障夹在一起，这不是问题。
The most important thing is to make sure you still have a proper air barrier. I won't go to far off on a tangent but please see this page aboutWRBs (weather resisistent barriers) as air barriers, because you could go with an exterior air barrier (see our exterior peel and stick membrane installation video), or you can use the standard 6 mil poly interior vapour barrier as an air barrier. Keep in mind thatpoly vapor barriers in homes with air condition are a problemin some locations, what climate zone or city are you in?
We also have this page onwood as an alternative to drywall for ceilingsthat may be of interest for figuring cost as well as some design options.
Hi Mike
Thanks so much for all this information. We live in southern Vancouver Island. We definitely want to avoid using 6 mil poly anywhere in our home. We are wondering if vapour barrier paint would be acceptable to the local building inspector (just trying to do research before we approach him) but would want a paint that is not toxic. We will also be doing T and G for the ceiling and ultimately it will be painted to better show off the ridge beam and half scissor trusses but we read in one of your links that vapour barrier paint is more applicable for walls so not sure what to do for the ceiling (roof is metal). Any other thoughts you have are greatly appreciated.
6 mil poly barriers are actually not as a big a problem with ceilings, the vapor drive isn't quite as problematic as with walls. In the Edelweiss Demo House we used vapour barrier paint on the walls but we used poly on the ceiling. As for your building inspector, that could go either way, so if you want to try vapour barrier paint (or vapour retarder primer) check with an inspector ahead of time. As for the toxicity, We used Benjamin Moore vapor barrier paint which was low VOC but not Zero VOC unfortunatetly.
The honest answer is that from a scientific point of view, painted wood will actually act as a vapour barrier, meaning vapour will move through it so slowly that it would qualify as a vapour barrier, but it is highly unlikely youll find a building inspector to accept that for new home construction. And I say that with the caveat that you should not even consider that if you don't have a proper air barrier in some other form. Be sure to read this page aboutthe difference between Air Barriers and Vapour Barriers因为它们经常组合在一个产品中，但执行完全不同的任务。