You can forego the plastic and use a vapor retarder kraft faced insulation or latex ceiling paint in all other climates except hot humid or hot dry climates.
Do i need a vapor barrier in attic.
Not every wall does.
After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.
Because it s nearly impossible to seal penetrations in the ceiling the reality is water vapor will get into the attic.
A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter.
The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it.
Plastic vapor barriers should only be installed in vented attics in climates with more than 8 000 heating degree days.
In hot dry climates your attic can be vented though like in hot humid climates you should not install any vapor retarder or barrier.
The theory is that part of the moisture vapor in the house is actually blocked by the drywall and paint on the.
Attic vapor barrier detail for cold climates even though we apply vapor barriers to exterior insulated walls in cold climates it s no longer recommended for ceilings floor of the attic.