How Many Roof Vents Do I Need In My Roof

You ll need the square footage of your attic to calculate the number of roof vents that you should need.

How many roof vents do i need in my roof.

The net free area nfa ratingindicates the amount of space each roof vent covers. Because you always want your intake nfa to meet or exceed the amount of exhaust nfa we will take the amount of exhaust provided and divide by the nfa rating of the deck air. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space.

Use the calculator below to find out how many exhaust and intake vents you will need on your house. Rounding up you would need ten 10 750 vents. To calculate the number of 750 vents needed divide 480 by 50 to get 9 6 vents. So if your attic is 450 square feet you will need 3 square feet of vent space evened out throughout the entire space and divided equally between inlet and outlet vents.

Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation for every 300 square feet of attic floor space evenly split between intake and exhaust. Near ridge of the roof. And this guideline you ll need a minimum of. You will need to have 1 square foot of vent area for every 150 square feet of attic space.