Vapour Barrier Garage Ceiling

You don t mention whether there is a bonus room or living space above the garage.

Vapour barrier garage ceiling.

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

Turbine vents are overkill. If you plan to insulate you should use a 6 mil poly vapour barrier on the walls and ceiling. 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. 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.

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 you re using old uninsulated doors pick up a retrofit kit that add insulating panels. Paper faced insulation is not a good vapour barrier.

Install as directed typically cutting to fit and using a staple gun to attach the vapor barrier to the studs. To know if you need a vapor retarder ask yourself a few basic questions. 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. However if you live in a cold climate zone such as alaska it s a good idea to install a vapor barrier on the warm in winter side of the wall.

You can forego the plastic and use a vapor retarder kraft faced insulation or latex ceiling paint in all other climates except hot humid or hot dry climates. Plastic vapor barriers should only be installed in vented attics in climates with more than 8 000 heating degree days.