Attic Ventilation Requirements Calculator

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.

Attic ventilation requirements calculator.

Use the duraflo ventilation calculator to determine your home s ventilation requirements. In our case the required 4 vents for the 1200 sq ft house multiply the 144 cubic inches by 4 576 cubic inches. Use avp s roof vent calculator to determine the number and size of exhaust vents you will need. According to the fha federal housing administration us for every 300 square feet of attic floor area you should have at minimum one square foot ventilation.

Calculate the total vent area needed. In order to find the right calculator divide the attic floor space by 300 sq feet. Here s how to determine your requirements. All lomanco attic ventilation product requirements are based on the minimum standard 1 300 rule as set forth by the international building code ibc and the international residential code irc.

Multiply the length of the attic times the width in feet to find the attic area then divide by 150 to find the total square feet of vent space needed. Ventilation calculator 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. Length x width of attic in feet 150 total sq. 1 cubic foot is 12 x 12 144 cubic inches.

Hence you would need two square feet 600 300 of attic ventilation. Next multiply the 4 square feet into cubic inches. If local code requires the 1 150 rule please double the requirements. As an example in an attic that is 30 feet by 20 feet you would have 600 square feet of floor area.

Determine the square footage of the attic or area to be vented choose your square footage 500sq 600sq 700sq 800sq 900sq 1000sq 1100sq 1200sq 1300sq 1400sq 1500sq 1600sq 1700sq 1800sq 1900sq 2000sq 2100sq 2200sq 2300sq 2400sq 2500sq 2600sq 2700sq 2800sq 2900sq 3000sq. Our soffit vents round back vents pop vents and universal vents make excellent intake vents. For balanced ventilation an equal amount of intake vent area net free area should also be installed. Vent calculatordesign your balanced ventilation system.

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.