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.

Attic ventilation requirements.

Calculating attic ventilation requirements. The roofing industry also has practical guide lines for attic ventilation. Typically building codes include minimum requirements applicable to attic ventilation. Result of item 1 300.

Divide the square footage item 1 by 300. Allows cool dry air to enter the attic. Most building codes require a ratio of 1 150 ventilation space to attic floor space. Feet of attic space divided 50 50 between the inlets and outlets.

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. Attic ventilation is an important part of keeping your building healthy. Intake vents located at the lowest part of the roof under the eaves allow cool.

Current regulations state that the minimum attic ventilation requirements are 150 1. The majority of the requirements related to attic ventilation have not changed much from the previous editions. The following are the requirements taken directly from the irc. 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.

Calculate the square footage of the attic space. 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. Foot of ventilation for every 150 sq.

Standard attic vents like af 50 s ventilation fans or solar powered attic fans. 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. Other options to meet your attic ventilation needs are. Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems.

This means that if you have a 1500 sq attic then you would need at least 10 sf of ventilation. The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes. 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.