Resolution of the vapor barrier debate.
How important is vapor barrier in attic.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
If your climate does not meet these conditions a vapor retarder like latex ceiling paint will work well for your house if you are in all other climates except the hot dry and hot humid.
A plastic vapor barrier is best installed in a vented attic within climates with over 8 000 heating degree days.
A vapor barrier in an attic assembly in a severely cold climate with the absence of an air barrier will likely be ineffective.
Throughout the balance of this digest the terms attic and roof will and can be used interchangeably.
In circumstances where conditions inside a home or office are much different than outdoor conditions water.
A vapor barrier is a thin layer of impermeable material typically polyethylene sheeting included in building construction to prevent moisture from damaging the fabric of the building.
Attic vapor barrier detail for cold climates the best approach for a vented attic in a cold climate is installing a layer of drywall with a good coat of latex paint the paint creates a semi permeable vapor barrier.
Do not add a vapor barrier on top of the insulation in your attic since the paper facing on the existing insulation is the vapor barrier.
Some debate still occurs over how necessary vapor barriers are but a consensus is growing closer.
Not every wall does.
Vapor barriers are a must for protecting your home against the damaging effects of moisture and keep your crawl space dry.
In cold climates the primary purpose of attic or roof ventilation is to maintain a cold roof temperature to control ice dams created by melting snow and to vent moisture that moves from the conditioned space to the attic ventilation acts to bypass the vapour barrier created by most roof.
Most authorities now agree that vapor barriers are important under certain conditions but not necessarily as a whole house solution for every home.
The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.
The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it.
