Attic Ventilation Requirements

Most building codes require a ratio of 1 150 ventilation space to attic floor space.

Attic ventilation requirements.

Ridge vents are one of the easiest ways to meet roof venting 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. Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems. Current regulations state that the minimum attic ventilation requirements are 150 1.

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. Code requirements the international building code. Standard attic vents like af 50 s ventilation fans or solar powered attic fans. 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. Allows cool dry air to enter the attic. The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes. The majority of the requirements related to attic ventilation have not changed much from the previous editions.

Hence you would need two square feet 600 300 of attic ventilation. The following are the requirements taken directly from the irc. Attic ventilation is an important part of keeping your building healthy. Calculating attic ventilation requirements.

The roofing industry also has practical guide lines for attic ventilation. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. Feet of attic space divided 50 50 between the inlets and outlets. Intake vents located at the lowest part of the roof under the eaves allow cool.

Divide the square footage item 1 by 300. Typically building codes include minimum requirements applicable to attic ventilation. Foot of ventilation for every 150 sq. This means that if you have a 1500 sq attic then you would need at least 10 sf of ventilation.

The two square feet is divided equally between the intake and the exhaust one square foot for each. Calculate the square footage of the attic space. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. The following product options will allow you to achieve an intake nfva of 528 square inches.