How Many Roof Vents Per Square Foot

Always have a balanced ventilation system.

How many roof vents per square foot.

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. 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. 1 square foot of ventilation for every 150 square feet of space. No vapor barrier and for some municipalities in hot climates.

And this guideline you ll need a minimum of. Always have a balanced ventilation system. In no case should the amount of exhaust ventilation exceed the amount of intake ventilation. In no case should the amount of exhaust ventilation exceed the amount of intake ventilation.

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. For pitched roofs with vapor barriers. This means that for every 300 square feet of enclosed attic space 1 square foot of ventilation is required with half at the upper portion exhaust vents and half in the lower portion intake vents. Near ridge of the roof.

This formula is traditionally used for static roof vents which are rated for net free area in terms of square inches. 1 square foot of ventilation for every 300 square feet of space.