See quantities below for each gaf ventilation product typically rounded up.
Calculating attic ventalation.
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.
According to their requirements you should have 1 square foot of attic ventilation per 300 sq ft of attic floor space.
Vent calculatordesign your balanced ventilation system.
Calculating attic ventilation requirements.
If local code requires the 1 150 rule please double the requirements.
If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation.
Our soffit vents round back vents pop vents and universal vents make excellent intake vents.
Roof ventilation calculator enter your attic area or length and width to determine your ventilation needs.
Enter the length and width of the attic floor or the total square footage of the attic floor.
Calculate the square footage of your attic and provide proper attic ventilation with the right number of roof vents ridge vents or soffit vents.
Calculate the total vent area needed.
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.
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.
Width or area.
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.
Enter square footage calculate or enter the square footage of the attic or area to be vented.
Select ventilation product flex roll ridge vent multi roll multi purpose vent rigid roll ridge.
Result of item 1 300.
Hit the calculate button for the recommended amount of exhaust and intake ventilation.
There should also be a 50 50 balance of attic venting and roof venting.
Length x width of attic in feet 150 total sq.
For balanced ventilation an equal amount of intake vent area net free area should also be installed.
Calculate the area of your attic and the proper number of vents.
Calculate the square footage of the attic space.
Determine the amount of ventilation needed for your home with this formula.