Venting Attic Space

Attic fans perform this ventilation by pushing hot air out into the environment while also pulling fresh cool air into the attic.

Venting attic space. Divide the attic s square footage by 150. A ridge vent is a ventilation strip that is placed along the ridgeline of the home. 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. Prior to installing the ridge vent a 1 inch wide strip of roof decking is cut out along both sides of the ridgeline to allow for air movement through the vent.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. It comes on an easy to install flexible mesh roll and is hand nailable with no complicated fitting wrapping nail gun adapters. That said air resistance and interference such as vent grates reduces the area of true ventilation. For instance attic ventilation is used widely in cold climates to evacuate the warm moist air that escapes from the living space below.

The result is a cooler attic space with plenty of air exchange. 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. Throughout the balance of this digest the terms attic and roof will and can be used interchangeably. Rarely will you find a building practice that works everywhere.

Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation. The following is a list of options for installing ventilation into a residential attic space. In cold climates the primary purpose of attic or roof ventilation is to maintain a cold roof temperature to control ice dams created by melting snow and to vent moisture that moves from the conditioned space to the attic ventilation acts to bypass the vapour barrier created by most roof. Intake vents located at the lowest part of the roof under the eaves allow cool.

When installed as part of a properly balanced when installed as part of a properly balanced attic ventilation system gaf cobra exhaust vent is a shingle over exhaust vent installed at the roof ridge that helps exhaust excess heat and moisture from your attic. Space attic vents evenly and mark the locations by driving nails up through the shingles photo 1. One reason for the lack of agreement over attic ventilation is the tremendous variation in climate across north america.