Attic Insulation Vapor Barrier Wrong Way

Though some batts come with a paper or foil facing that can act as a vapor barrier tom silva prefers to use 6 mil polyethylene sheeting cut to fit between the joists and with seams sealed by foil tape to prevent moisture from seeping into insulation.

Attic insulation vapor barrier wrong way.

If you install fiberglass batt insulation with a kraft paper vapor retarder in a home which way do you face the vapor retarder. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. For many building science questions the answer is it depends for this one the answer is clear.

If you re insulating from scratch put the right vapor barrier in the right place. However all attics vented or unvented and in all climates should have an air barrier such as an airtight drywall ceiling. The application can vary so read all instructions on your specific brand of paint. Gradually roll the barrier out and use your chosen method to secure it at regular intervals.

Instead of pulling away the insulation sheets to slip in the barriers apply at least one thick coat maybe two to the insulation. As you work sweep your hand across the surface to push out air and keep the barrier flat. To the inside of the home or the outside of the home. Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers.