Key takeaways
- Good ventilation has air coming in low and leaving high.
- A common guide is one square foot of vent area per 150 square feet of attic floor.
- Blocked soffit vents are a common problem.
- Balance matters more than the number of vents.
An attic is not just storage. It is a space between your living area and the roof, and the air in it matters.
What ventilation does
In summer, it lets hot air escape so shingles and the house stay cooler. In winter, it lets moist air out so frost and mold do not form.
Intake and exhaust
Cool air enters through soffit vents at the eaves and warm air leaves through a ridge vent or other exhaust at the top. The two must be balanced.
How much do you need?
A common guide is one square foot of net vent area for every 150 square feet of attic floor, split evenly between intake and exhaust. Our Attic Vent Calculator does the math.
Common problems
Insulation blocking the soffit vents, painted-over vents and mixing different kinds of exhaust vents on the same roof all cause trouble.
Insulation helps
Insulation keeps heat in the living space, and ventilation keeps the attic itself dry. They work as a pair.
Related services
Questions about your own roof? Call or text 615-431-3789, or use the quote form below.