Short Answer
Attic ventilation helps manage heat and moisture. A properly designed ventilation system generally uses intake ventilation and exhaust ventilation working together.
Detailed Explanation
Attic ventilation serves two critical functions: removing excess heat in summer and removing moisture in winter. In summer, a poorly ventilated attic can reach 150°F or more, which heats the living space below, overworks air conditioning, and accelerates shingle aging from underneath. In winter, warm moist air from the living space rises into the attic and, without proper ventilation, condenses on cold surfaces — leading to mold, wood rot, and wet insulation. A proper ventilation system uses intake vents (usually at the soffit) to bring in cool, dry outside air and exhaust vents (usually at or near the ridge) to let warm, moist air escape. This continuous airflow keeps the attic temperature closer to the outside temperature and manages moisture.
Why It Matters
Poor ventilation is one of the leading causes of premature roof failure, attic mold, and energy waste — yet it's often overlooked during roof replacement.
Common Mistakes
- ✕Installing a new roof without evaluating or upgrading ventilation
- ✕Adding exhaust ventilation without adequate intake
- ✕Blocking soffit vents with insulation
Questions to Ask Your Contractor
- ?Is my attic ventilation adequate?
- ?Do I have both intake and exhaust ventilation?
- ?Is my insulation blocking soffit vents?
- ?Should ventilation be upgraded during my roof replacement?