How Many Vents Does My Roof Need

Choose one of the following products to meet the recommended exhaust nfva of 528 square inches.

How many vents does my roof need.

Even if you have vents in your roof you still need to have soffit vents to allow the air to circulate naturally. As a general rule your roof needs 1 square foot of vent area for every 150 square feet of attic space. I have roof vents so i have roof ventilation. Roofing resources during.

Ridge static attic vents 384 00 minimum sq. How many vents will my house need. Most codes use the 1 300 rule for minimum residential attic ventilation recommendations. 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 for every 300 square feet of attic floor space evenly split between intake and exhaust. 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. Click here to get free fast bids from local roofers who can install turbine vents. If the winds are still the vents still allow air to drift up and out of the attic space although not nearly as much.

Take for example ridge vents. The general rule of thumb in these situations is of roughly one vent per every 300 square feet of attic area if the attic has a vapor barrier. Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof. The majority of roofing experts agree that ridge vents are the most effective and cost effective roof vents available.

Watch my video below. For the 1 150 attic ventilation requirement simply double the amount of exhaust and intake calculated. 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. A single 14 inch diameter turbine vent that is subjected to 15 mph winds can expel up to 1 342 cfm of air.

Thus if your attic is 450 square feet you need roof vents equaling 3 square feet. The first step in determining how many vents you need is to calculate the net free area nfa required. Of net free area of exhaust needed at or near the ridge. Ventsure 4 foot strip heat moisture ridge vent.

Of net free area of intake needed at or near the soffit. How many vents do i need. These specialty vents do not affect the. While hardly anybody agrees on the best roof ventilation system everybody agrees some roof vents do hardly any good at all.