Roof Ventilation: Facts Every Homeowner Should Know

Without adequate ventilation, warm, humid air won’t be able to exit your roof and attic, creating a damp environment that’s the perfect breeding ground for mold and rot. That’s why it’s important that your roof and attic have adequate ventilation.



Here are some of the other facts you need to know about roof and attic ventilation:

More Ventilation Isn’t Necessarily Better

If there are too many air vents, the airflow—which should be balanced—in your roof and attic will be disrupted. How much ventilation does your roof need? It depends on the total attic floor space. In general, there should be a square foot of net free area (NFA) (the area through which air can pass through) for every 300 square feet of floor area for attics with a vapor barrier. And if your attic doesn’t have a vapor barrier, there should be a square foot of NFA for every 150 square feet of attic floor space. If you’re not sure if your roof and attic have enough air vents, you should have a roofing contractor conduct an inspection.

Not All Air Vents Can Provide the Same Level of Ventilation

To optimize ventilation in your roof and attic, the right type of air vent needs to be installed. Here’s an overview of the most widely used air vents:

• Box vents – Box vents, which are installed near the top of the roof, don’t provide a lot of venting space. As such, you’ll need to install several of them to make sure your roof and attic are well-ventilated.
• Ridge vents – Ridge vents, which are often installed on shingle roofing systems, have more venting capacity than box vents and are a smart choice if you want to preserve your home’s curb appeal. Since they run along the roof peak, they won’t draw attention to themselves.
• Turbine vents – Turbine vents rely on wind to draw out humid air from your roof and attic.

To learn more about your options, consult a professional exterior remodeling contractor.

Here’s a pro-tip: It’s best to consult local contractors. Since they’re familiar with the local climate and building codes, they can make better recommendations.

TJ Exteriors Inc. has been providing professional roof replacement services to local residents since 1985. To get a free estimate, call us at (952) 448-4312 or fill out this form.