What is the best way to get my existing roof to "breathe" more?
I have a cookie-cutter home here in Phoenix with an asphalt roof, and I need my attic to breathe. I would like a list so I can prioritize. If I could only do one thing, what should I choose? Solar attic fan, roof vents, etc.?
Review your existing roof venting.
- Do you have adequate soffit and roof vents?
- For a balanced system, you are required to have 50% of venting at the soffit and 50% at the highest point of the roof.
To calculate the required amount of vent, use the following equations.
- 150 square inches of ventilation per square foot of attic for a balanced system.
- 350 square inches of ventilation per square foot of attic for a non-balanced system.
The best type of soffit venting to install is a continuous soffit vent system. Make sure also that all spaces between the joists and rafters allow for a minimum of 1.5 inches of clear ventilation from soffit to ridge.
Also, at the highest point on the roof, I would recommend the installation of a quality continuous ridge vent.
- Do not install a combination of venting.
- For example, do not install ridge vents if you have gable vents or roof "can" vents lower than the ridge.
This will not allow the soffit vents to function and will defeat their purpose.
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