How Many Turbine Roof Vents Do I Need

As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space.

How many turbine roof vents do i need.

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. Because you always want your intake nfa to meet or exceed the amount of exhaust nfa we will take the amount of exhaust provided and divide by the nfa rating of the deck air. How to determine how many vents you need 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. Furthermore this will ensure that a continuous supply of air moves through the desired space.

To calculate the number of 750 vents needed divide 480 by 50 to get 9 6 vents. Most policies in place require about one foot of vent area for every one hundred fifty feet of attic space. This is one of the most important steps. Roofing resources during covid 19 for contractors for homeowners.

If you install a vent that isn t up to code you could end up having to take it down wasting money and time. 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. Ft of vent space half dedicated for air intake in the soffits and the other half for exhaust on the roof. A small 12 inch diameter turbine vent with a constant wind speed of 5 miles per hour mph can remove 347 cubic feet of air per minute cfm from the attic space.

These can be ridge vents wind turbines or the flat vents your roofer wants to install. 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. How many turbine vents you will need depends on a number of factors including the size and type of building. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator.

Good attic ventilation is important for preventing ice dams in the winter. Having the correct number of turbine vents will provide an effective and balanced system. Attic must have 5 sq. Also this will give you general guidelines to follow as you complete your project.

A single 14 inch diameter turbine vent that is subjected to 15 mph winds can expel up to 1 342 cfm of air.