Roof Venting By Roof Sq Footage

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.

Roof venting by roof sq footage.

For balanced ventilation an equal amount of intake vent area net free area should also be installed. Standard ridge vent produces 18 square inches of ventilating area per lineal foot. Nine hundred square inches equals 6 25 square feet. For the 1 150 attic ventilation requirement simply double the amount of exhaust and intake calculated.

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. If this is not possible and the homeowner does not have any documentation on file listing attic square footage you could use the footprint of the house aerial view of the house or the number of shingle squares one. Of net free area of exhaust needed at or near the ridge. Ideally the attic square footage would be measured at the attic floor length x width regardless of roof pitch by the way.

Of net free area of intake needed at or near the soffit. Ridge static attic vents 384 00 minimum sq. Based on your 1100 sq. And this guideline you ll need a minimum of.

So the ridge ventilation has exceeded the minimum requirement. Use avp s roof vent calculator to determine the number and size of exhaust vents you will need.