Attic Airflow Balancing Tips
A well-designed attic venting system is important to prevent ice dams and other roof damage. It’s also essential to balancing attic ventilation, so the right amount of air comes in and out. If there’s too much exhaust in the attic, it can choke the intake vents and cause a problem. Too little intake in the attic can lead to excessive moisture and heat buildup, causing roof damage.
One of the most effective ways to balance spray foam insulation airflow is with a combination of soffit vents and ridge vents, which allow outside air to enter the attic through soffit vents, rise over the attic space, then exit through ridge vents near the top of the attic. The ideal ratio is about 50% intake and 50% exhaust. In most cases, a venting calculator will help you determine the proper ratio for your roof or attic.
Intake vents should be placed in the soffits or eaves. The exhaust vents should be located at the ridge of the attic. The two vents should work together to draw in cool, dry outdoor air and release hot, moist attic air. The resulting airflow helps to reduce overheating and moisture in the house, while protecting insulation and extending the life of the roofing system.
If your attic is unfinished, you may not have soffit vents, but you can still balance the ventilation system by adding gable vents or installing other intake venting systems (e.g., static vents) at the gable ends of your home. Make sure that your vents are not blocked by debris, birds’ nests, or even paint. Performing simple tests with a smoke pencil can also give you insights into how well your vents are working and highlight areas that need improvement.
Joe Blow’s Insulation
29712 US Hwy 19 N Unit 409 Clearwater, FL 33761
727-454-0172