Attic Ventilation Requirements

Code requirements the international building code.

Attic ventilation requirements.

Calculating attic ventilation requirements. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. The two square feet is divided equally between the intake and the exhaust one square foot for each. 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. A ridge vent is a ventilation strip that is placed along the ridgeline of the home. The majority of the requirements related to attic ventilation have not changed much from the previous editions. The roofing industry also has practical guide lines for attic ventilation.

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. Feet of attic space divided 50 50. Hence you would need two square feet 600 300 of attic ventilation. 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.

Divide the square footage item 1 by 300. 1 300 ventilation ratio recommended. This means that if you have a 1500 sq attic then you would need at least 10 sf of ventilation. Result of item 1 300.

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. Calculate the square footage of the attic space. 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.

Attic ventilation is an important part of keeping your building healthy. The recommended ventilation ratio to provide for vented attic assemblies when an air barrier is present is the 1 300 ratio as specified by most building codes. It is important that air movement occurs and is not impeded by any framing members of the. Intake vents located at the lowest part of the roof under the eaves allow cool.

The following are the requirements taken directly from the irc. Foot of ventilation for every 150 sq.