Attic Ventilation Requirements

Allows cool dry air to enter the attic.

Attic ventilation requirements.

Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems. 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. Feet of attic space divided 50 50 between the inlets and outlets. Ridge vents are one of the easiest ways to meet roof venting requirements.

The following are the requirements taken directly from the irc. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. This means that if you have a 1500 sq attic then you would need at least 10 sf of ventilation. Other options to meet your attic ventilation needs are.

The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. Hence you would need two square feet 600 300 of attic ventilation. Attic ventilation is an important part of keeping your building healthy.

Standard attic vents like af 50 s ventilation fans or solar powered attic fans. Calculate the square footage of the attic space. The following product options will allow you to achieve an intake nfva of 528 square inches. Choose one of the following products to meet the recommended intake nfva of 528 square inches.

Result of item 1 300. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Most building codes require a ratio of 1 150 ventilation space to attic floor space. Code requirements the international building code.

Current regulations state that the minimum attic ventilation requirements are 150 1. Foot of ventilation for every 150 sq. Divide the square footage item 1 by 300. Calculating attic ventilation requirements.

The roofing industry also has practical guide lines for attic ventilation. Intake vents located at the lowest part of the roof under the eaves allow cool. Typically building codes include minimum requirements applicable to attic ventilation. The majority of the requirements related to attic ventilation have not changed much from the previous editions.