Attic Ventilation Requirements

1 300 ventilation ratio recommended.

Attic ventilation requirements.

This means that if you have a 1500 sq attic then you would need at least 10 sf of 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. The majority of the requirements related to attic ventilation have not changed much from the previous editions.

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

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. Hence you would need two square feet 600 300 of attic ventilation. Attic ventilation is an important part of keeping your building healthy. Result of item 1 300.

Feet of attic space divided 50 50. Current regulations state that the minimum attic ventilation requirements are 150 1. The following are the requirements taken directly from the irc. Divide the square footage item 1 by 300.

The two square feet is divided equally between the intake and the exhaust one square foot for each. 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. Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems. 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. Code requirements the international building code. Typically building codes include minimum requirements applicable to attic ventilation. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

The roofing industry also has practical guide lines for attic ventilation. Calculating attic ventilation requirements.