Vapor Barrier Tongue And Groove Ceiling

Whether or not you need a vapor retarder hinges on three main factors your climate your home and the location of the wall you re insulating.

Vapor barrier tongue and groove ceiling.

Don t forget to use airtight electrical boxes and to seal all of the air leaks at all penetrations. The biggest air barrier blunder is to install tongue and groove boards as your finish ceiling without first installing taped. That leads me to believe heated air may be escaping the rooms through the gaps. I am attaching the planks directly to the bottom of trusses.

The ceiling boards have a noticeable gap at the tongue and groove. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. The best air barrier under tongue and groove boards is a layer of gypsum wallboard. I am concerned with air dust dirt leakage between the planks.

Gba has long advised people installing a tongue and groove board ceiling to first install an air barrier of gypsum drywall. To know if you need a vapor retarder ask yourself a few basic questions. I am considering putting up poly or tyvek. If you pay attention to airtightness when you install your air barrier you don t have to worry very much about vapor diffusion.

I am adding a tongue and groove cedar plank ceiling to a heated room in my pole barn. For example see how to build an insulated cathedral ceiling. Should i have a vapor barrier between the planks and the blown in insulation. It s also incorrect in a way.

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.