Air Infiltration From Attic Through Ceiling

The opening around a furnace or water heater lue or chimney can be a major source of warm air moving in the attic.

Air infiltration from attic through ceiling.

A form of un controlled attic ventilation will also have an influence on the moisture balance. If you have an attic ac unit you should take this opportunity to check the air seals on the duct work. It reduces energy consumption because the temperature in the attic is lower. Spray foam also reduces infiltration through the ceiling.

This is building science 101. Fill ceiling box gaps with fire blocking foam invert the spray foam can and shove the tube up into the gap. Look for dirty insulation which is evidence that air is moving through it. During the summer standard ceiling insulation reduces the transfer of heat from the attic to the living space.

In the day temperatures can get up to 140f in the attic. Let it cure for about two hours. Loose connections should be clamped taped and caulked. The easiest way to find air leaks is with a blower door.

During the summer standard ceiling insulation reduces the transfer of heat from the attic to the living space. Gently squeeze the trigger and slowly pump foam into the gap. The two control layers we re concerned about here are. Additionally the air tightness of the attic construction itself the un intentional air infiltration i e.

Where walls inner and outer meet the attic floor dropped soffits dropped ceiling areas and behind or under attic kneewalls. Because the pipe gets hot building codes usually require 1 inch of clearance from metal lues 2 inches from masonry chimneys to any combustible material including insulation. Spray foam also reduces infiltration through the ceiling. Consider swapping out or upgrading any duct work that is not insulated properly.

Once this air sealing work is done you may want to add more insulation to your attic floor. It reduces energy consumption because the temperature in the attic is lower. As long as the roof isn t leaking the biggest wintertime source of attic moisture is air infiltration from the conditioned space through the attic floor air sealing the house at the attic floor basement band joist can do a lot for reducing 24 365 outdoor air infiltration which is the major driver of summertime indoor humidity levels. One source is from outdoors through the attic ventilation and the other is from indoors through air leakage across the ceiling plane.

In the day temperatures can get up to 140f in the attic. Then there are the control layers meant to control the flow of heat air and moisture across the building envelope. Once in the attic refer to your sketch to locate the areas where leakage is likely to be greatest. If you want to add insulation remember that air leaks have to be sealed first.