Vapor Barrier Tongue And Groove Ceiling

I am adding a tongue and groove cedar plank ceiling to a heated room in my pole barn.

Vapor barrier tongue and groove ceiling.

It s also incorrect in a way. The ceiling boards have a noticeable gap at the tongue and groove. The article includes this advice. Should i have a vapor barrier between the planks and the blown in insulation.

That leads me to believe heated air may be escaping the rooms through the gaps. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Don t forget to use airtight electrical boxes and to seal all of the air leaks at all penetrations. If you pay attention to airtightness when you install your air barrier you don t have to worry very much about vapor diffusion.

The biggest air barrier blunder is to install tongue and groove boards as your finish ceiling without first installing taped. To know if you need a vapor retarder ask yourself a few basic questions. I am considering putting up poly or tyvek. I am concerned with air dust dirt leakage between the planks.

My thought is to remove the batts and install 1 foil faced foam board foil towards the heated rooms then seal any gaps between the foam board and ceiling rafters. Now i m a real fan ha ha of controlled mechanical ventilation to limit interior moisture levels in cold and mixed climates as well as to. For example see how to build an insulated cathedral ceiling. I am attaching the planks directly to the bottom of trusses.

The best air barrier under tongue and groove boards is a layer of gypsum wallboard.