Should There Be Vapor Barrier In Attic

The previous owner has 1 foam insulation with a a plastic vapor barrier only on the rafters of the roof about4 from the slate roof but not on the walls of the attic.

Should there be vapor barrier in attic.

Now with attic insulation heat is no longer lost from the living space such that moisture may remain trapped in the attic vapor barriers were therefore necessary to reduce moisture flow into the attic. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. In hot dry climates a vapor retarder should also not be installed but attics can be vented. I want to install insulation in my attic floor which i use for storage.

To stop the movement of vapor effectively through air leaks your vapor barrier should also have an air barrier such as an airtight. Because it s nearly impossible to seal penetrations in the ceiling the reality is water vapor will get into the attic. Should i staple a vapor barrier over the joices and in between then put my insulation. A vapor barrier in an attic assembly in a severely cold climate with the absence of an air barrier will likely be ineffective.

Modern homes or offices that are tightly sealed in order to be highly energy efficient should also have air to air heat exchangers or other methods of ensuring a good exchange of fresh air. In any case the vapor barrier must point to the warm side. A vapor barrier or vapor diffusion retarder is a material that reduces the rate at which water vapor can move through a material. I just want to be able to work in there once in a while over the winter.

Even though we apply vapor barriers to exterior insulated walls in cold climates it s no longer recommended for ceilings floor of the attic. In hot humid climates attics should not be vented and vapor retarders should not be installed on the interior of assemblies. Buildings should meet ashrae standards 62 2 or 62 1 for proper ventilation before being sealed by complete vapor barriers. This barrier is meant to keep moisture from getting to the insulation in the walls and ceilings and it is required by building codes when insulating most houses.

All vented and unvented attics should have an air barrier regardless of climate. Attic vapor barrier detail for cold climates. 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.