Vapor Barrier Paint For Attic

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.

Vapor barrier paint for attic.

Sherwin williams has a moisture vapor barrier latex paint b72w00001 that comes in at less than 1 perm. I install my vapor barrier in the middle of the wall system between the two walls. A vapor barrier or vapor diffusion retarder is a material that reduces the rate at which water vapor can move through a material. Benjamin moore has a super spec primer k206 00 that is a latex paint and comes in at less than 0 5 perms.

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 vapor barrier in an attic assembly in a severely cold climate with the absence of an air barrier will likely be ineffective. In 2017 dalia kaminski of montreal needed some and has shared with me some very thorough research. Some debate still occurs over how necessary vapor barriers are but a consensus is growing closer.

Most authorities now agree that vapor barriers are important under certain conditions but not necessarily as a whole house solution for every home. Climates vapor barriers or more accurately vapor diffusion retarders should be part of a moisture control strategy for a home. Vapour barrier paint or vapor barrier paint in the u s. Resolution of the vapor barrier debate.

On the other hand an air barrier a properly detailed air tight drywall ceiling for example in the absence of a vapor barrier can be effective since it stops the flow of vapor laden air. Is more of a solution for walls rather than ceilings to prevent the indoor vapour drive during hot humid weather. It combines a primer and finish in a single fast drying coat and is specially formulated for manufactured housing facilities. Moisture vapor barrier primer finish interior latex is a coating designed to reduce the loss of moisture through walls and ceilings.

The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. Such a location works both as a vapor barrier as well as an air barrier and eliminates the need for an external air barrier not a easy application on a multi storried building as well as any special electrical pans and their sealing. Over time this trapped moisture can rot the wood framing in your attic or cause mold and mildew to appear. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers.