Calculating Attic Ventalation

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.

Calculating attic ventalation. Divide the square footage item 1 by 300. Our soffit vents round back vents pop vents and universal vents make excellent intake vents. Result of item 1 300. Select ventilation product flex roll ridge vent multi roll multi purpose vent rigid roll ridge.

Calculate the area of your attic and the proper number of vents. If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation. Calculate the square footage of the attic space. See quantities below for each gaf ventilation product typically rounded up.

Calculate the total vent area needed. Determine the amount of ventilation needed for your home with this formula. Use avp s roof vent calculator to determine the number and size of exhaust vents you will need. Calculate the square footage of your attic and provide proper attic ventilation with the right number of roof vents ridge vents or soffit vents.

According to their requirements you should have 1 square foot of attic ventilation per 300 sq ft of attic floor space. Enter square footage calculate or enter the square footage of the attic or area to be vented. Width or area. For balanced ventilation an equal amount of intake vent area net free area should also be installed.

If local code requires the 1 150 rule please double the 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. 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. 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. Hit the calculate button for the recommended amount of exhaust and intake ventilation. Calculating attic ventilation requirements. Length x width of attic in feet 150 total sq.

There should also be a 50 50 balance of attic venting and roof venting.