Do I Need A Vapor Barrier In Attic

Air sealing an attic.

Do i need a vapor barrier in attic.

Seal the air leakage pathways. You do not need a vapor barrier. A vapor barrier in an attic assembly in a severely cold climate with the absence of an air barrier will likely be ineffective. Since you already have insulation if there was a moisture problem you probably would have noticed signs of it already.

The basics of air sealing are covered in this article. 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 following are a few simple steps to help you undertake the task properly so your vapor barrier retains heat without damaging the insulation. Several layers of paint on the ceiling would qualify as a vapor barrier.

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. 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. Most forms of attic insulation benefit from the addition of a vapor barrier to protect them from the harmful effects of moisture which can reduce their effectiveness over time.

Do i need a vapor barrier. However all attics vented or unvented and in all climates should have an air barrier such as an airtight drywall ceiling. If you are not sure if you need insulation in your walls follow along with this flow chart. Your first job after the studs are in place is to fill those walls with insulation.

No you don t need a vapor barrier. What you need is an air barrier that is at every step of the way you have to pay attention to airtightness. The paper facing contains a layer of impermeable asphalt that prevents water vapor from passing through it. No you don t need a vapor retarder class i or otherwise.

Because it s nearly impossible to seal penetrations in the ceiling the reality is water vapor will get into the attic. Hi beth 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. For example the recommended vapor barrier in a home or office in a humid southern climate built with brick varies. When it comes to the stairway leading into your attic you should heed the advice in this article.

By the time you paint the drywall though you ve brought it into the class iii vapor retarder range between 1 and 10 perms and even less water vapor will diffuse through.