Regarding attic ventilation nrca recommends designers provide at least 1 square foot of nfva for every 150 square feet of attic space 1 150 ventilation ratio measured at the attic floor level ceiling.
Rule roof ventilation.
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.
Good roof ventilation can do this but shingle color sun exposure and insulation are exponentially more important to overall energy efficiency than ventilation.
Too many people believe the importance of roof ventilation is to increase energy efficiency during the summer.
The first step is to check out this 60 second video and learn about the 300 1 rule the difference between intake and exhaust ventilation and why proper ventilation is so important to get right to help calculate your attic ventilation needs visit gaf ventilation calculator.
Hit the calculate button for the recommended amount of exhaust and intake ventilation.
Hot air exhaust vents located at the peak of the roof allow hot air to escape.
Calculate or enter the square footage of the attic or area to be vented.
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.
Of attic floor space.
Wash the underside of the roof deck with air.
That means the entire perimeter of the roof needs to have air inlets meaning continuous soffit ventilation.
Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic.
This means for every 150 square feet of attic floor space there should be 1 square foot of net free area.
A ridge vent is a ventilation strip that is placed along the ridgeline of the home.
The code minimum for attic ventilation in the 2012 irc section r806 roof ventilation is as follows.
By gaf roof views.
If you re actually going to vent the roof let s be serious about venting the roof.