Roof Vents Per Square Foot

And this guideline you ll need a minimum of.

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. But what happens if we choose to use those individual metal pot vents instead. Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. This shortcut conveniently calculates the 2015 international residential building code minimum irc section r806 roof ventilation 1 which states in part 1 square foot of net free area for every 150 square feet of attic floor space with the attic defined as length x width floor of the attic.

1 square foot of ventilation for every 300 square feet of space for pitched roofs with vapor barriers 1 square foot of ventilation for every 150 square feet of space no vapor barrier and for some municipalities in hot climates. Near ridge of the roof. Nine hundred square inches equals 6 25 square feet. This formula is traditionally used for static roof vents which are rated for net free area in terms of square inches.

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. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. Use this calculator to help determine the proper amount of attic ventilation based on u s. Building codes typically echo the administration s guidelines.

Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. Based on your 1100 sq. So the ridge ventilation has exceeded the minimum requirement. Standard ridge vent produces 18 square inches of ventilating area per lineal foot.

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. The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. Our roof is 50 feet long so using a standard product we will get 900 square inches of ventilating space.