Ventilation may not be at the top of your list of things to worry about when installing a residential roof, but maybe it should be. After all, air flow, or the lack of it, has a lot to do with energy efficiency, the formation of ice dams and even that deadly black mold from hell we’ve been hearing so much about.
Attics may be ventilated with powered ventilators or a system of fixed static vents, including exhaust vents (ridge vents, roof vents, gable vents and turbines) and intake vents (undereave, cornice or soffit vents). These vents must be balanced, as Principles of Attic Ventilation explains, “In general, the net-free area of intake venting should equal the net-free area of exhaust venting … Net-free area means the total unobstructed area (usually measured in square inches) through which air can enter or exhaust a static ventilation component.”