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Roof and Attic Ventilation: Do I Need Gable Vents & Power Fans?

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For many homeowners, improperly ventilated roofs and attics are a common issue. As we previously shared in our post about ridge vents, sufficient ventilation matters for multiple reasons. To recap, proper ventilation can help extend the life of your roof and help keep your home more energy efficient – which will save you money. Unfortunately, many homes are plagued with some major ventilation mistakes that can adversely affect their roofs and their home’s interior environment.

Common Mistake 1 – Gable Vents

One mistake we see often on many homes is the pairing of gable vents with ridge and soffit vents. To supply air to the ridge vents, a home needs ventilation at the roof eave or in the overhang. Soffit vents, when added in addition to ridge and gable vents, will result in interruption of proper air flow. Air should flow in through the intake vents evenly along the roofline and flow out the peak. Any vents placed between the ridge vents and the intake vents may interrupt the flow of air along the roofline. The gable vents will become the intake for the ridge vent – and that could lead to weather infiltration through the gable vents and prevent proper ventilation in the attic.

Common Mistake 2 – Power Fans

We also see a lot of homes with power fans installed in addition to ridge vents. The more ventilation the better, right? Not in this case! Mixing a power vent with a ridge vent can interrupt the attic ventilation system just like a gable vent will. Air will follow the path of least resistance, so when the power vent turns on, it will pull air from the ridge vent. That could lead to weather infiltration and unbalanced airflow along the underside of the roof deck. When the power vent is off, it acts as an opening on the roof and the ridge vent will pull its intake air from the power fan. Again, this can cause weather infiltration and inadequate ventilation along the underside of the roof deck.

We recommend never mixing two different types of exhaust vents on a roof that has a common attic. It can interrupt proper ventilation and create problems for your roof.

Feel free to contact us if you have any questions about proper roof and attic ventilation. And be sure to tune into our next post!

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