There should also be a 50 50 balance of attic venting and roof venting.
Calculating attic ventalation.
To find out how many soffit vents you need to install.
Hence you would need two square feet 600 300 of attic ventilation.
If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation.
See quantities below for each gaf ventilation product typically rounded up.
Select ventilation product flex roll ridge vent multi roll multi purpose vent rigid roll ridge.
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.
Hit the calculate button for the recommended amount of exhaust and intake ventilation.
Calculate the soffit vent area needed divide the total vent area by two to determine the soffit vent area.
Enter the length and width of the attic floor or the total square footage of the attic floor.
Let s use the following simple ranch house for an example.
Calculating ventilation area ok to determine how much ventilation area you need for your house all you need to know is the square foot area of the attic to be ventilated.
As an example in an attic that is 30 feet by 20 feet you would have 600 square feet of floor area.
Jones takes this measurement and divides it by 150 for a total of 7 36 square feet of ventilation space that is needed.
Our passive roof vents are ul certified and rated to withstand wind pressure in excess of 200 mph.
Jones has an attic space that measures 23 feet by 48 feet.
The house measures 30 feet by 50 feet.
Calculate or enter the square footage of the attic or area to be vented.
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.
According to their requirements you should have 1 square foot of attic ventilation per 300 sq ft of attic floor space.
This yields a total area of 1 104 square feet.
Calculate the total vent area needed multiply the length of the attic times the width in feet to find the attic area.