2009 Irc Roof Ventilation Requirements

The following are the requirements taken directly from the irc.

2009 irc roof ventilation requirements.

U factor and total ua res check approach. Between half and two thirds of the provided ventilation shall be installed at the eaves. Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems. For impact rated fenestration complying with section r301 2 1 2 of the irc or section 1608 1 2 of the ibc maximum u factor shall be 0 75 in zone 2 and 0 65 in zone 3.

The roofing industry also has practical guide lines for attic ventilation. The ventilation openings shall have a least dimension of 1 16 inch 1 6 mm minimum and 1 4 inch 6 4 mm maximum. 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. Code requirements the international building code.

Where the roof sheathing is less than 3 4 inch 19 1 mm thick the nails. Ventilation openings shall have a least dimension of 1 16 inch 1 6 mm minimum and 1 4 inch 6 4 mm maximum. January 2009 code for residential buildings that creates minimum regulations for one and two family dwellings of three stories or less. Vented attics shall have a minimum net free ventilation area at least 1 300 of the area of the vented space.

The majority of the requirements related to attic ventilation have not changed much from the previous editions. Typically building codes include minimum requirements applicable to attic ventilation. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction. It brings together all building plumbing mechanical fuel gas energy and electrical provisions for one and two family residences.

Where the roof sheathing is less than 3 4 inch 19 mm thick the. Fasteners for asphalt shingles shall be galvanized stainless steel aluminum or copper roofing nails minimum 12 gage 0 105 inch 2 67 mm shank with a minimum 3 8 inch diameter 9 5 mm head of a length to penetrate through the roofing materials and a minimum of 3 4 inch 19 1 mm into the roof sheathing.