Roof Attic Ventilation Requirements

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 attic ventilation requirements.

Enter square footage calculate or enter the square footage of the attic or area to be vented. Attic ventilation requirements how many attic vents your roof needs industry standard for proper attic ventilation recommends for no vapor retarder type of attic insulation no paper plastic or aluminum layer between the attic floor and insulation layer 1 sq. Typically building codes include minimum requirements applicable to attic ventilation. You can calculate attic ventilation requirements by determining the square footage of your attic.

Feet of attic space divided 50 50. The amount of space you devote to intake must be equal to the amount you allow for exhaust and these must be calculated according to the size of your attic and slope of your roof. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. The roofing industry also has practical guide lines for attic ventilation.

Foot of ventilation for every 150 sq. Most building codes require a ratio of 1 150 ventilation space to attic floor space. See the benefits of attic ventilation a new roof is more than just shingles. The following are the requirements taken directly from the irc.

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. The key to proper ventilation of your roof and attic is balance. Intake vents located at the lowest part of the roof under the eaves allow cool. The majority of the requirements related to attic ventilation have not changed much from the previous editions.

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. If you don t know how your roof vents work or if you re unsure about your attic ventilation in general you should talk to a roof inspector about your current system and any inherent weaknesses that may be at. Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems. Code requirements the international building code.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.