How Many Roof Vents Do I Need

For example if you have 1200 square feet of attic space you should need at least 4 air vents to ensure proper ventilation.

How many roof vents do i need.

You will need to have 1 square foot of vent area for every 150 square feet of attic space. 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. Always have a balanced ventilation system. 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.

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. Based on your 1100 sq. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. Some local building codes carry special considerations that take precedence.

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. How many vents will my house need. The net free area nfa ratingindicates the amount of space each roof vent covers. Near ridge of the roof.

Keep in mind you should always consult with a professional roofing company when determining how many air vents your roof should have. 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. In no case should the amount of exhaust ventilation exceed the amount of intake ventilation. Fan calculation as a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space.

And this guideline you ll need a minimum of.