Know Your Roof · Soffit & Fascia
Soffit Vents: Types and How They Work
Quick answer
Soffit vents are openings in the underside of your roof overhang that let cool outside air into the attic. They're the intake half of attic ventilation: air comes in low at the soffit, rises as it warms, and leaves through a ridge vent or other exhaust up high.
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Why airflow matters
A ventilated attic runs cooler in summer and drier in winter. With Cincinnati's hot, humid summers and cold winters, steady airflow helps protect the roof deck and the insulation. It also helps keep the roof surface evenly cold in winter, which cuts down on ice dams. Insulation and air sealing matter just as much, though, so vents alone won't fix an ice dam problem.
Types of soffit vents
Continuous strip vents are a long slot running along the soffit, and they give even airflow. Individual vents are rectangular or round and spaced along the soffit. Fully vented panels are perforated along their whole length.
What blocks them
Insulation pushed up against the roof deck is the big one, because it covers the opening. Baffles (also called rafter vents) hold an air channel open. Paint over the slots, dirt and insect nests can block them too.
Intake has to match exhaust
Too much exhaust and too little intake can pull air out of the house. Too little of both leaves the attic stuffy. When ventilation is the question, a roofer should look at both ends.
Looking for another word? See the roofing terms glossary, A to Z.