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Lack of attic vapor barrier

I am ready to add insulation to my attic. The attic is well ventilated (now) as I have installed fully vented soffits and my new roof has a ridge vent, plus I have gable vents with a fan on one end. I have the soffit baffles in. Problem-I only have about 4" blown in fiberglass with no vapor barrier. Do I remove the existing insulation and add a vapor barrier or just insulate over the existing? I live in the Baltimore-DC area.

Re: Lack of attic vapor barrier

Sounds like you could probably just right over the existing insulation with more insulation.

Re: Lack of attic vapor barrier

do not put a vapor barrier over the insulation, it's supposed to go between the ceiling and the bottom of the insulation. if you leave what you have there in place and get some r-13or r-19 to fill the rest of the joist depth that would cover you up to the top of the joists, i assume the joists are 2x8's. then, if you can, at least in the areas that you don't use, i would get some r-36 and lay them horizontal to the joists, up nice and tight to one another and then you'll have a nicely insulated attic.

Timothy Miller
Re: Lack of attic vapor barrier

Hi, consider getting a bid to add additional blown in fiberglass to get a total R38 to R50. You do not need to remove the currant insullation just add more.
If your ceiling is drywall and painted you already have a good vapor barrier. There are paints for ceilings designed to be used as a vapor barrior- inquire at a paint store.

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