Air Barrier In The Attic

Ideally no services such as hvac distribution ducts air handlers plumbing or fire sprinkler systems should be located external to the air barrier figure 3.

Air barrier in the attic. The reduced heat gain may even allow for a smaller air conditioning system. Hey i ve bashed fiberglass here in this blog. Just because a failure in the air control layer air barrier shows up in the heat control layer insulation doesn t mean it s the fault of the insulation. Gaps in the attic or between the lower floors and the attic will let heated or cooled air escape to the great unconditioned outdoors making any insulation you add essentially useless.

Adding a second vapor barrier could cause condensation to become trapped in the insulation between the two vapor barriers. Attic insulation should always be installed with the paper backing facing toward the living space the ceiling in this case. Attics heat up when the sun s radiant energy heats the shingles and the heat is transferred to the interior attic space through the roofing materials via conduction. Some studies show that radiant barriers can reduce cooling costs 5 to 10 when used in a warm sunny climate.

Radiant barriers are utilized to reduce summer heat gain in attics. Find a diagram of common air leaks here here s a quick primer on fixing draft prone spots. Radiant barriers are more effective in hot climates than in cool climates especially when cooling air ducts are located in the attic. Properly sealing and insulating attic knee walls can significantly reduce air leakage and heat loss between the conditioned space and the unfinished attic.

The insulation fiberglass or cellulose is then placed on top of the drywall with no vapor barrier above or below. This acts as a barrier to keep heated moist air from rising up into the attic during cold weather. It is important to choose an air barrier and insulation material that will reduce the air leakage and heat loss as much as possible. 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.