Attic Ventilation Requirements

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

Attic ventilation requirements. Hence you would need two square feet 600 300 of attic ventilation. Foot of ventilation for every 150 sq. 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. 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. Attic ventilation is an important part of keeping your building healthy. The roofing industry also has practical guide lines for 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.

Roof insulation thermal resistance at roof perimeter should be equal or greater to thermal resistance of exterior wall. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. 1 300 ventilation ratio recommended. Prior to installing the ridge vent a 1 inch wide strip of roof decking is cut out along both sides of the ridgeline to allow for air movement through the vent.

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. The following are the requirements taken directly from the irc. It is important that air movement occurs and is not impeded by any framing members of the.

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. A ridge vent is a ventilation strip that is placed along the ridgeline of the home. 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.

Result of item 1 300. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. 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. Typically building codes include minimum requirements applicable to attic ventilation.

Feet of attic space divided 50 50. 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.