Blog – Expert Roofing Advice & Tips

Residential Roof Vents Part One – How They Work

While it may seem simple, your home’s roof is a complex system that includes your attic, which houses your roof’s support structure, and your eavestroughs and downspouts, which help get rid of the water that your roof keeps out of your home. Together they are all designed to protect your home from temperature extremes, rain, wind, snowand anything else Mother Nature has to offer.

One of the least known and understood parts of your roofing system is the ventilation of your roof and attic. But, without proper ventilation, your roof would not last as long, your home would not be as comfortable and your heating and air conditioning costs would be higher.

How Roof Vents Work

Roof vents are placed in openings on the surface of your roof, along the roof’s soffit and/or in the gables of your roof.  Basically, roof vents allow air to circulate through your roof and attic. Some vents are mainly designed to remove air from the attic and some are mainly designed to let air in.

Roof vents offer different benefits to your home and roof depending on the season.

    1. In Summer – Air circulation in your roof helps cool the attic, which in turn keeps your home cooler and reduces your air conditioning costs. That air circulation also helps reduce the moisture that might seep into your roof through small cracks after a rain shower. If moisture stays in your roof, it can cause mould and mildew to grow which in turn could lead to wood rot and reduced r-values for the insulation in your attic. It could also lower the air quality in your home


  1. In Winter – Roof vents help balance air temperatures inside your attic with air temperatures outside. That helps stop condensation from forming. Having condensation is like having a leak. The moisture that builds up from condensation can damage your roof’s structure and also reduce the air quality in your home.

Clearly roof vents are an important part of your roofing system. A general rule of thumb is that your need one square foot of venting area for every 300 square feet of attic area. But, depending on your location and the exposure of your roof, you may need more or less venting.

In Part Two of this series, we will tell you about the different types of roof vents that are available for your home.

Please note: Chouinard Bros. does not recommend any homeowner complete repairs to their roof of their own. Our technicians are skilled at performing this work and have received years of training to understand how to complete repairs safely.

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