Attic Insulation Vapor Barrier Up Or Down

The heat being lost from the house below warmed up the attic so that moisture was lost through the vents as vapor.

Attic insulation vapor barrier up or down.

You have made the bold decision to insulate your attic. As of right now there is about 7 of blown in insulation in the attic. Attic hatch or door. I do not see a vapor barrier underneath the current insulation.

Affix rigid foam insulation to the attic side of the hatch or door. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. Yes you should put unfaced insulation either rolls or batts on top of existing insulation so that you only have on vapor barrier facing the heated house.

If you install fiberglass batt insulation with a kraft paper vapor retarder in a home which way do you face the vapor retarder. 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. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. To the inside of the home or the outside of the home.

Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. In this case use r 38 insulation as recommended above by energystar. Use a zippered insulated tent to keep the enclosure draft free attic tent at 7 attic cover insulator 120. I will be blowing in approximately another 10 to get an r38 value i live in wisconsin.

If the batts are your only layer meaning the attic joists are currently uninsulated you should install them with the vapor barrier down facing your living area below. Add weatherstripping around the perimeter and a sweep to the door of a walk up attic. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. Not every wall does.

The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. Pull down stair or ladder. 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. In any case the vapor barrier must point to the warm side.

For many building science questions the answer is it depends for this one the answer is clear. Reply dee january 15 2015 at 8 12 pm. 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.