Stopping Air is the Second Most Important Job of a Building Enclosure
Next to rain, air leaks through walls, roofs, and floors can have a HUGE effect on the durability of a house. Uncontrolled air flow through the shell can not only carry moisture into framing cavities causing deteriation of the structure, it can account for a very large portion of a home’s energy use.
Energy efficiency requires a tight shell and good indoor air quality. In “leaky” homes, large volumes of air — driven by exhaust fans, furnace fans, the stack effect, and wind — can blow through the home’s floor, walls, and ceiling. Because air usually contains water vapor, these uncontrolled air leaks can cause condensation. Homes needs an adequate air barrier and a controlled ventilation path.