Roof Attic Ventilation Requirements

Intake vents located at the lowest part of the roof under the eaves allow cool.

Roof attic ventilation requirements. 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. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. 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.

See the benefits of attic ventilation a new roof is more than just shingles. The following are the requirements taken directly from the irc. You can calculate attic ventilation requirements by determining the square footage of your attic. Foot of ventilation for every 150 sq.

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. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. 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. The roofing industry also has practical guide lines for attic ventilation.

Most building codes require a ratio of 1 150 ventilation space to attic floor space. Typically building codes include minimum requirements applicable to attic ventilation. 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. Most effective ventilation uses a ridge and soffit continuous ventilation system but even these designs can vary from roof to roof.

Effective attic ventilation systems reduce damaging heat and moisture in your attic promote energy efficiency by helping to reduce the load on your air conditioner in the summer and also reduce the risk of ice dam formation on your roof. The key to proper ventilation of your roof and attic is balance. Feet of attic space divided 50 50. Enter square footage calculate or enter the square footage of the attic or area to be vented.

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.