Minimum Attic Ventilation Requirements

Code requirements the international building code.

Minimum attic ventilation requirements.

Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems. 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 federal housing authority fha and the urban development hud have established minimum requirements 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.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Based on your 1100 sq. The roofing industry also has practical guide lines for attic ventilation. According to their requirements you should have 1 square foot of attic ventilation per 300 sq ft of attic floor space.

Attic ventilation is an important part of keeping your building healthy. Figure 1 soffit to ridge attic ventilation. Of net free area of exhaust needed at or near the ridge. Ridge static attic vents 384 00 minimum sq.

The majority of the requirements related to attic ventilation have not changed much from the previous editions. In order to have a balanced ventilation system you need to have the right roof vent calculation. At least code required minimum ventilation b balance ventilation between intake and exhaust c control heat moisture and air fl ow between the attic and the occupied space this document outlines reasons for ventilating roofs provides design guidelines discusses regulatory requirements and identifi es roof ventilation. Intake vents located at the lowest part of the roof under the eaves.

According to the fha federal housing administration us for every 300 square feet of attic floor area you should have at minimum one square foot ventilation. Of net free area of intake needed at or near the soffit. The following are the requirements taken directly from the irc. Current regulations state that the minimum attic ventilation requirements are 150 1.

And this guideline you ll need a minimum of. 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. Exhaust nfva near ridge of the roof. As an example in an attic that is 30 feet by 20 feet you would have 600 square feet of floor area.

The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction.