Posted on: 14 May 2019Share
When you have a new roof installed or put in new attic insulation, it's a good time to think about attic ventilation. Ventilation is important for your attic, even though it may seem like you should keep air sealed out of the attic for energy efficiency. While you do want to seal up leaks, you also want to allow the right amount of ventilation to prevent problems with your roof and home. Here's why attic ventilation is important and how you may want to ventilate your attic.
Why Proper Attic Ventilation Matters
Ventilation is important in all climates and all seasons of the year. In the winter, ventilation protects your roof from the heat inside your house. It does this by allowing cool air to circulate through the attic to counter the warm air that rises to the top of your house from your furnace. Having adequate attic insulation helps with this too as it blocks heat from rising up from your home. Keeping your attic cold in the winter is important so that when it snows, the heat from inside the attic doesn't melt snow that then refreezes and causes an ice dam.
A properly vented attic prolongs the life of your roof even if you rarely get snow. By keeping the attic space under the roof cool, the shingles won't get as hot, which is a benefit since hot shingles can wear down faster. This is especially important in hot weather. If your attic isn't ventilated in the summer, heat will build in the attic. This causes your roofing to be warmer and it can also make it more difficult to keep your home cool. Without the right amount of ventilation, your home can suffer from roof damage, excess heat, and problems with humidity.
How To Improve Attic Ventilation
Attic ventilation is a type of building science. Several things affect how much ventilation your attic needs. A contractor will calculate this based on the square footage of your attic and the slope of your roof. Through calculations, the contractor can let you know how much ventilation you should have and the best way to achieve that amount. One thing to note is that venting air from a bathroom or kitchen into the attic is not the same thing. Those vents should go to the outside. Attic ventilation uses outdoor air that circulates through the attic space.
If you're getting new insulation, then you may want the contractor to install baffles along the perimeter of the attic to allow circulation through soffit vents. When insulation is installed, it's important not to seal off soffit vents. Installing baffles can help keep air flowing even when insulation is up against the wall. If you're having a new roof put on, then your roofer may want to add vents at the same time so shingles can be fitted around the protrusions if there are any. Attic vents can be placed on the ridge of the roof and soffit. They can be placed on a roof gable or they can protrude through the roof and be static or powered by wind. You'll need intake vents which are usually lower on the roof and exhaust vents which are higher so air is constantly pulled in and pushed out of your attic. A contractor can help you determine the right type of vent for your house and climate, and you may want a say in the choice too since a vent might affect the appearance of your roof or home.