The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it.
Attic insulation vapor barrier cellulose.
Insulation labs is a name to reckon with for efficient vapor barrier installation services.
A vapor barrier is not only unnecessary but also can be potentially harmful especially during the summer months in air conditioned buildings when warm moist air passes through wall assemblies and condenses on the outside of the cool poly vapor barrier.
They help keep moisture from migrating into walls by diffusion but still allow for drying so it doesn t get trapped.
Air sealing an attic.
The best way to answer this question in addition to considering the factors above would be to talk to a professional.
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.
This article explains the necessary work.
Vapor barriers in attics should only be installed on one side of the insulation.
With our vapor barrier installation services there will be no issue of the crawl space of your home becoming a residence for pests bats and rodents.
If you decide to go ahead with the plan to install cellulose on the attic floor you don t need a vapor barrier.
But you do need to perform air sealing work before beginning the insulation job.
No the best option is to install un faced or loose fill fiberglass or cellulose on top of your drywall.
It s actually a smart vapor retarder since its permeability decreases as moisture content increases.
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.
The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below.
Since some leakage of moisture into the insulation in inevitable murphy s law you want it to be able to freely escape from the insulation into the attic.
Should you install a vapor barrier over preexisting attic insulation.