2009 Irc Roof Ventilation Requirements

It brings together all building plumbing mechanical fuel gas energy and electrical provisions for one and two family residences.

2009 irc roof ventilation requirements.

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 majority of the requirements related to attic ventilation have not changed much from the previous editions. The ventilation openings shall have a least dimension of 1 16 inch 1 6 mm minimum and 1 4 inch 6 4 mm maximum. Code requirements the international building code.

Fasteners for asphalt shingles shall be galvanized steel stainless steel aluminum or copper roofing nails minimum 12 gage 0 105 inch 3 mm shank with a minimum 3 8 inch 10 mm diameter head astm f 1667 of a length to penetrate through the roofing materials and a minimum of 3 4 inch 19 mm into the roof sheathing. 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. Where the roof sheathing is less than 3 4 inch 19 1 mm thick the nails.

Vented attics shall have a minimum net free ventilation area at least 1 300 of the area of the vented space. The following are the requirements taken directly from the irc. Open vent pipes that extend through a roof shall be terminated at least 6 inches 152 mm above the roof or 6 inches 152 mm above the anticipated snow accumulation whichever is greater except that where a roof is to be used for any purpose other than weather protection the vent extension shall be run at least 7 feet 2134 mm above the roof. 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 roofing industry also has practical guide lines for attic ventilation. U factor and total ua res check approach. Where the roof sheathing is less than 3 4 inch 19 mm thick the. Between half and two thirds of the provided ventilation shall be installed at the eaves.

Ventilation openings shall have a least dimension of 1 16 inch 1 6 mm minimum and 1 4 inch 6 4 mm maximum. Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems.