Attic Ventilation Requirements

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

Attic ventilation requirements.

1 300 ventilation ratio recommended. 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. The roofing industry also has practical guide lines for attic ventilation. Intake vents located at the lowest part of the roof under the eaves allow cool.

This means that if you have a 1500 sq attic then you would need at least 10 sf of ventilation. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. Attic ventilation is an important part of keeping your building healthy. The following are the requirements taken directly from the irc.

The majority of the requirements related to attic ventilation have not changed much from the previous editions. Code requirements the international building code. Current regulations state that the minimum attic ventilation requirements are 150 1. 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.

Hence you would need two square feet 600 300 of attic ventilation. Feet of attic space divided 50 50. Result of item 1 300. 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. Calculating attic ventilation requirements. It is important that air movement occurs and is not impeded by any framing members of the. Foot of ventilation for every 150 sq.

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. Typically building codes include minimum requirements applicable to attic ventilation. The two square feet is divided equally between the intake and the exhaust one square foot for each.

Divide the square footage item 1 by 300. 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.