Vapour Barrier Garage Ceiling

And the ceiling acts as a enough of a vapor retarder.

Vapour barrier garage ceiling. If you re adding new garage doors be sure to install insulated options. The classic answer is that the vapor barrier goes on the warm in winter side of the assembly. Install as directed typically cutting to fit and using a staple gun to attach the vapor barrier to the studs. 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.

This is because no matter how warm you keep you garage when that overhead door opens you fill the garage with cold moist air and this will build up as condensation between the poly and the spray foam. If your garage is 45 degrees and you have a bonus room heated to 72 degrees above the garage the vapor retarder faces the upstairs room. Turbine vents are overkill. Paper faced insulation is not a good vapour barrier.

If you plan to insulate you should use a 6 mil poly vapour barrier on the walls and ceiling. As long a the ceiling is air tight and the ventilation is only above the garage adding ventilation is fine. Plastic vapor barriers should only be installed in vented attics in climates with more than 8 000 heating degree days. Most garages don t need vapor barriers because the amount of vapor that diffuses through garage walls ceilings and the floor is not enough to cause wet walls that result in moisture damages.

Because the closed cell spray foam acts as a vapour barrier if you cover it again with the poly vapour barrier you will have condensation troubles between the two materials. If you re using old uninsulated doors pick up a retrofit kit that add insulating panels. A rigid vent with somewhat less free air area than the existing soffit ventilation is preferred since that lowers the pressure difference across your ceiling air barrier. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.

First of all a garage is not a signicant source of vapor as it is not occupied that much and you don t cook or bath in in it. To know if you need a vapor retarder ask yourself a few basic questions.