How far apart should soffit vents be spaced?

Why even spacing matters

Air entering at a soffit vent mostly travels straight up the rafter bay it enters, under the baffle, toward the ridge. A bay with no vent at its foot gets little airflow along its deck, even if the attic as a whole has plenty of vent area. That is why continuous strip vents and fully perforated soffit panels perform so well: they feed every bay.

Practical spacing for individual vents

• Space them evenly along the full eave on every side of the house, not just the front.
• Line them up with rafter bays and their baffles so the opening is not hidden behind a rafter.
• Keep them away from spots where bath fans, dryer vents or kitchen exhaust exit near the eave, so the attic does not inhale that moist air.
• Skip soffit sections over a porch ceiling or a closed bump-out that does not connect to the main attic, unless that space needs its own ventilation.
• Put a vent near each end of every eave, since the corners of hip roofs are where airflow tends to die.

Check the total

Once the spacing is set, add up the net free area of all the vents and compare it with what the attic needs: roughly 0.24 square inches of intake per square foot of attic floor under the balanced 1/300 rule. If you fall short, closer spacing or a switch to strip vents fixes it. Wood soffits on older homes can usually take a continuous strip vent cut down the center. See roof ventilation basics and roof anatomy explained.