The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction.
2009 irc roof ventilation requirements.
Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems.
Ventilation openings shall have a least dimension of 1 16 inch 1 6 mm minimum and 1 4 inch 6 4 mm maximum.
It brings together all building plumbing mechanical fuel gas energy and electrical provisions for one and two family residences.
Typically building codes include minimum requirements applicable to attic ventilation.
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.
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.
Where the roof sheathing is less than 3 4 inch 19 1 mm thick the nails.
The following are the requirements taken directly from the irc.
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 ventilation openings shall have a least dimension of 1 16 inch 1 6 mm minimum and 1 4 inch 6 4 mm maximum.
The majority of the requirements related to attic ventilation have not changed much from the previous editions.
Where the roof sheathing is less than 3 4 inch 19 mm thick the.
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.
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.
Code requirements the international building code.
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.
The roofing industry also has practical guide lines for attic ventilation.
U factor and total ua res check approach.
