Generally as the roof pitch increases the volume inside the attic also increases along with the amount of needed.
Estimating ventilation requirements for attic.
Calculating attic ventilation requirements.
Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems.
Hence you would need two square feet 600 300 of attic ventilation.
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.
Standard attic vents like af 50 s ventilation fans or solar powered attic fans.
How does roof pitch come into play when calculating attic ventilation current irc requirements do not factor the role a roof s pitch plays in the amount of attic ventilation needed but ventilation manufacturers do.
The two square feet is divided equally between the intake and the exhaust one square foot for each.
Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator.
The roofing industry also has practical guide lines for attic ventilation.
Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
The open area of a vent is sometimes listed on the roof air vent as nfva net free vent area.
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.
If not measure the size yourself.
Divide the square footage item 1 by 300.
Result of item 1 300.
Code requirements the international building code.
The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes.
Attic ventilation requirements how many attic vents your roof needs industry standard for proper attic ventilation recommends for no vapor retarder type of attic insulation no paper plastic or aluminum layer between the attic floor and insulation layer 1 sq.
In of vent opening per 150 sq.
It is important that air movement occurs and is not impeded by any framing members of the.
Calculate the square footage of the attic space.
Then aim for about 1 sq.
Ridge vents are one of the easiest ways to meet roof venting requirements.
A ridge vent is a ventilation strip that is placed along the ridgeline of the home.
Intake vents located at the lowest part of the roof under the eaves allow cool.
Other options to meet your attic ventilation needs are.
Enter square footage calculate or enter the square footage of the attic or area to be vented.
Typically building codes include minimum requirements applicable to attic ventilation.
Foot of ventilation for every 150 sq.
