Attic Ventilation is Important

Attic ventilation often confuses homeowners who have invested in insulating their homes– if you have insulated your home to keep in heat during the winter and cold during the summer, why would you want the outside air flowing through the attic? Because attic ventilation has several purposes.

Ice damming poor attic ventilation 

One of the most common functions of attic vents for northern homes is that it reduces the chances of ice damming in the winter by allowing a flow of cold air to circulate through the attic space. This prevents the snow from melting on the roof into the gutters for it to freeze again. The fluctuation of freezing and unfreezing can cause the gutters to dam up with ice and potentially back up under the shingles causing leakage.

Though it may seem counter-intuitive, roof vents are also invaluable during the summer. The reason is that heat rises and the build-up is often in the highest point of your home; the attic. A balanced ventilation system allows cold air to flow into the attic during the winter, and hot air to flow out during the summer. Thus, speeding up the amount of time it takes for your home to cool down while reducing your energy costs.

Air flow direction ridge vent

In addition to reducing your electric bill, attic ventilation can help to keep your shingles in good condition for a much longer time, so they don’t need to be replaced nearly as often as they otherwise would. This is because air vents cool the shingles, which slows down oxidation and helps to keep them from growing brittle due to heat damage. The attic vents will also encourage moisture to move out of the attic, preventing mold and rot.

There are several different types of air vents. These are the most common:

Ridge vent shingled.

Ridge Vents:

A ridge vent goes along the length of the roof’s peak. It blends into the roof itself, which keeps the home attractive, and provides even ventilation for the entire roof. It maximizes the air flow over the whole underside of the roof and is not greatly impacted by wind direction or temperature.




soffit vent

Intake Vents:

These vents run underneath the overhang of a roof eave and make up the soffit. The air from the soffit circulates to the intake vents to draw heat and moisture away from the house.



foundation vent


Foundation Vents:

These vents serve primarily to remove moisture that may cause rot or encourage mold to grow. They contain a fan that will run quietly, generally at a lower speed, when humidity levels grow too high. They can be manual or automatic, with a humidistat or thermostat to control when they run.






static roof vents

Static vents:

Static vents, like wind turbines, use air pressure and wind to allow air to flow out of the attic. These are often ideal for people who live in regularly breezy areas and want an inexpensive form of ventilation. They work well year-round, and are very cost efficient, which makes them a popular choice.




Whole-house fans

Whole-House Fans:

Generally installed in a hallway, whole-house fans are an efficient way to blow hot, stale air out of the home from stoves, ovens and cramped spaces. They work especially well for cooling the house when they are used after sundown or early in the morning, before it gets hot outside.






In summary, attic ventilation does more than make your attic comfortable and rid your home of stale air. In addition to reducing your cooling bill during the summer, air vents can help to preserve your home’s condition by preventing ice damming, removing humidity that can rot away at the foundation of your home, and lowering the temperature of your roof to protect your shingles. The benefits and the wide variety of vents available make them an excellent investment for any homeowner.

In order to realize the full efficiency performance and energy savings that a ventilation system can provide it’s important to select the proper vents for your particular roofing set up. This is why it’s a good idea to hire professionals like us, because we’re experts at what we do and we can help you determine the best balanced configuration for optimal effectiveness. Ideally this would be 50% intake with 50% exhaust. There are situations that the ideal balance won’t be possible so in that case it’s better to have more in-take because the excess in-take will convert to exhaust on the lee side of the house.