Attic Ventilation Requirements Calculator

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.

Attic ventilation requirements calculator.

Select ventilation product flex roll ridge vent multi roll multi purpose vent rigid roll ridge. Length x width of attic in feet 150 total sq. Calculate the total vent area needed. The majority of the requirements related to attic ventilation have not changed much from the previous editions.

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. If your roof is 1200 sq ft soffit floor space you will need 4 sq feet of roof ventilation. There should also be a 50 50 balance of attic venting and roof venting. If local code requires the 1 150 rule please double the requirements.

Our passive roof vents are ul certified and rated to withstand wind pressure in excess of 200 mph. 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. Width or area. A 50 x 30 attic would have a total area of 1 500 sq.

Ft divided by 150 equals 10 sq. 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. Home attic vent calculator for years we have been working with architects and specifiers to ensure affordable roof ventilation that upholds building code standards. Divide the square footage item 1 by 300.

The following are the requirements taken directly from the irc. Gaf attic 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. Calculate the square footage of the attic space.

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. Use this calculator to help determine the proper amount of attic ventilation based on u s. Vent calculator design your balanced ventilation system. Result of item 1 300.

Roof ventilation calculator enter your attic area or length and width to determine your ventilation needs. The two square feet is divided equally between the intake and the exhaust one square foot for each. In order to find the right calculator divide the attic floor. Calculating attic ventilation requirements.

Hence you would need two square feet 600 300 of attic ventilation.