Proper attic ventilation is important, especially for homes located in climates where snow and ice dams are common. Take advantage of summer weather to inspect your home for adequate attic ventilation and make necessary repairs or improvements.
A well-ventilated attic helps expel warm air and refresh it with cooler outside air. The National Roofing Contractors Association (NRCA) says proper air circulation can help:
- Remove excess heat and moisture from attics to prevent condensation that could lead to mold and mildew,
structural damage and ice
dams during winter.
- Reduce the average air temperature inside an attic during summer.
- Maintain the manufacturer's warranty on some asphalt shingle systems.
Types of attic vents: Attic ventilation recommendations range from 1 square foot of ventilation for every 150 square feet of attic space to 1 square foot for every 300 square feet. According to the NRCA, a common way to vent asphalt roofs is with non-powered or "passive" ventilation that balances air intake with air exhaust. Common passive vents include:
- Ridge vents. Exhaust vents installed along the roof's peak that are either covered by shingles or
exposed along the ridgeline.
- Static vents. Individual protected exhaust vents installed near the roof's ridge.
- Gable vents or wall louvers. Exhaust vents placed in walls at gabled ends of an attic that can function
as both intake and exhaust vents.
- Wind turbine vents. Exhaust vents that use wind power to turn an internal fan, drawing hot air from the
attic. Compared to static vents, these can increase the rate at which air is expelled, depending on
- Soffit vents. Continuous or individual vents installed along an attic's soffits or eaves. Soffit vents should never be blocked by insulation.
The NRCA provides additional information about attic ventilation on its website.