How Many Roof Vents Do I Need

Thus if your attic is 450 square feet you need roof vents equaling 3 square feet.

How many roof vents do i need.

Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space. They should be divided equally between inlet and outlet vents and they can be used in any combination that will work with your roof s design. Always have a balanced ventilation system. The rule of thumb used to determine the number of roof vents to install is one for every 300 square feet of attic area if your attic has a vapour barrier and one for every 150 square feet of attic area if the attic does not have a vapour barrier.

Keep in mind you should always consult with a professional roofing company when determining how many air vents your roof should have. And this guideline you ll need a minimum of. Near ridge of the roof. For example if you have 1200 square feet of attic space you should need at least 4 air vents to ensure proper ventilation.

For the number of soffit vents in the example divide 8 square feet of ventilation needed by 0 5 for the number of rectangular vents required 16 in the example. Choosing round soffit vents for. 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. How many vents will my house need.

Based on your 1100 sq. 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. You ll need the square footage of your attic to calculate the number of roof vents that you should need. The net free area nfa ratingindicates the amount of space each roof vent covers.

In no case should the amount of exhaust ventilation exceed the amount of intake ventilation.