Number Of Vents For Roof

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.

Number of vents for roof.

As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space. The area of soffit and roof vents is typically measured in 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. Advantages of proper roofing ventilation.

Proper attic ventilation offers numerous advantages to the homeowner. Use the factor 1 square foot 144 square inches to convert. 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. For example if your roof structure has a ventilated area of 150 m 2 and you wish to use the lomanco bib12 unit you would need three units for an efficient and balanced ventilation system.

If your attic floor has an area of 1 500 square feet for example you need 10 square feet of ventilation space unless your house has a vapor retarding liner in which case you need 5 square feet. The table below is a guide that can be applied to most common roof types and pitches. Building codes typically echo the administration s guidelines. 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.

The next step is to select a suitable exhaust vent and intake vent that fits the roof design for best performance and best aesthetics. It s time to install. The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. 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.

27 lineal feet required. Although there are many different types of roof vents to choose from ensuring you have the right number of both intake and exhaust vents is a central part of roof design. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. Use the calculator below to find out how many exhaust and intake vents you will need on your house.

Ventsure 4 foot strip heat moisture ridge vent with weather protector moisture barrier. Ventsure 4 foot strip heat moisture ridge vent.