Attic ventilation is the movement of outside air through the attic space. In a typical vented attic, cooler air enters near the eaves and warmer, moist air exits near the top of the roof.
Why It Matters
Ventilation helps manage heat and moisture. It can affect comfort, condensation risk, ice-dam conditions, and how roofing materials perform over time.
Common Problems
Common issues include blocked intake vents, not enough exhaust, too many competing exhaust types, bathroom fans venting into the attic, and insulation blocking airflow paths.
Building Codes & Industry Standards
The International Residential Code includes attic ventilation provisions, and roofing manufacturers often include ventilation expectations in product guidance. Requirements can vary based on assembly type, climate, and local enforcement.
Exterior Echelon Notes
Exterior Echelon reviews attic ventilation when evaluating roofing projects because the roof surface and the attic space are connected parts of the same system.
