Roof Of Factory With Roof Ventilators

How to Calculate Roof Ventilation

Roof ventilation is a great way to lengthen the life of your roof and make the most of your investment.

Proper roof ventilation will ensure that temperatures in the house stay more consistent, saving you on energy costs as well. It can also protect against rot in the attic and in the roofing materials.

But how much roof ventilation is needed to be effective?

What Is Roof Ventilation?

Roof vents installed in the roof allow for greater air flow through the attic space without letting in bugs or moisture.

When properly installed, the roof vents allow air to escape from the attic, which can stop the roof materials from melting in high heat as well as stop moisture from building up.

How Do I Calculate Roof Ventilation?

The key to effective roof ventilation is not just the type of vents that you install but their number and placement. Your primary goal is balance to ensure that there is enough air flow across the entire area of the roof.

Calculating your roof ventilation needs is simple. All you have to do is compute how much net free area you need to cover and then give yourself one square foot of ventilation for every 300 square feet of enclosed space in the attic.

Half of your roof vents will provide exhaust; the other half of the vents offer air intake.

For example, if you have building with 6,000 square feet of attic space, then you will need 20 square feet of attic ventilation. You calculate this by dividing 6,000 square feet of attic space by 300 square feet to get the number of vents total.

Because you want to have a balanced system, half of those vents will be intake vents and the other half will be exhaust vents. You will need 10 of each in this example.

NOTE: When you go to purchase your vents, you will find that they are rated per square inch of coverage rather than square foot, so you will need to remember that 144 square inches equals 1 square foot.

How Much Ventilation Does My Roof Need?

Contact us at Four Seasons Roofing today to set up a consultation and get your roof ventilation project started.

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