Vapor Barrier Detached Garage Ceiling

Basically you want to use unfaced insulation when you don t need a vapor barrier or have a separate one.

Vapor barrier detached garage ceiling. 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. Omitting a ceiling vapor barrier by arguing that you have to let the moisture escape or because the house has to breathe out the top is actually correct in a way. Thus installing vapor barriers on wall surfaces must. If you re using old uninsulated doors pick up a retrofit kit that add insulating panels.

I am starting the process of insulating my detached 23 x 32 garage in buffalo ny cold lots of snow winters with the secondary goal of having constant natural gas overhead heat keeping. Water vapor can pass through building materials in several ways including direct transmission and by heat transfer but studies suggest that fully 98 percent of the moisture transfer through walls occurs through air gaps including cracks around electrical fixtures and outlets and gaps along baseboards. Install as directed typically cutting to fit and using a staple gun to attach the vapor barrier to the studs. Unfaced means there s no paper barrier on one side of the insulation.

I live in mn and am insulating my garage ceiling in an attached garage. If you re adding new garage doors be sure to install insulated options. To know if you need a vapor retarder ask yourself a few basic questions. This is normally done because it s the most cost effective method to achieve the desired level of comfort and ease of installation.

Matt risinger a builder in texas on the cutting edge of building science yes that is a thing has a great video about whether or not you need a vapor barrier. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. It also has the advantage of letting out any moisture that may get through the interior vapor barrier. 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.

And the ceiling acts as a enough of a vapor retarder. The tyvek is intended to keep rainwater from getting to the sheathing. I ve read the articles here and on other sites and it seems like i can t get a final decision. The traditional way to insulate the walls and ceiling of a typical garage is to install fibreglass batt insulation in the walls and attic space followed by a six mil poly air vapour barrier and drywall.

It s also incorrect in a way. On the one hand i ve read about how air leakage is the main culprit of transporting moisture so i plan to air seal as best as i can with spray foam and caulk. Yes you should because the vapor barrier should always be installed on the warm side of the wall. I m so confused about vapor barriers.