What are the new roof ventilation systems, and should a new roof include one?
Short answer. The newer ventilation products are mostly refinements: shingle-over ridge vents with external wind baffles and filters, intake vents that install at the roof edge on homes without soffits, and solar powered attic fans. The bigger opportunity is the replacement itself, because a new roof is the cheapest time to correct an attic that was never balanced.
What has changed in vent products
- Baffled, filtered ridge vents. Modern shingle-over ridge vents use an external baffle that deflects wind over the vent, creating low pressure that helps pull air out, plus filter fabric that keeps out insects and wind-driven rain.
- Edge intake vents. Houses with little or no soffit can now get intake through a vent installed along the lower edge of the roof, under the first shingle courses, so a ridge vent still has air to draw from.
- Solar attic fans. These run on their own small panel with no wiring. They help in specific cases but share the downside of any powered fan when intake is short.
- Better intake strips. Continuous soffit vents and fully vented soffit panels offer more net free area than the old round plugs or a few rectangular vents.
Why the replacement is the moment to fix it
During a tear off the decking is exposed, so a crew can cut a ridge slot, remove and deck over old box vents and add edge intake for far less than it would cost later. If your old roof had mixed exhaust, such as a ridge vent plus box vents plus a gable fan, the replacement is the time to pick one exhaust type and size it to the intake.
What to ask for in the estimate
Ask the roofer to write down the existing intake and exhaust, the proposed vents and the net free area math. A good estimate lists ridge vent by the linear foot, any box vents being removed and decking repairs. Robust Roofing walks through that sequence in its guide to roof replacement day. Also see what to expect on replacement day and ridge vent vs box vents.