February 12, 2008

Why is Attic Ventilation Important?
The constant, year-round movement of air across the attic is a process that can improve home comfort, reduce damage to the roof structure and help keep a roofing warranty valid. Every time stale, overheated air is vented out of the home, and fresh air is pulled in to replace it, you have an "air exchange." The process of air exchange is more than a breeze moving through the home. It's a process that provides a steady, high volume of air movement. It's a system of components, all sized and positioned to create a balanced flow of intake and exhaust air moving though the attic.                    

Vent Requirements
A balanced ventilation system means about 50% of the required ventilating area should be provided by exhaust vents in the upper portion of your attic with the remaining 50% provided by intake vents.

Please remember, building codes specify the minimum amount of ventilation. You may want to increase the requirement to ensure proper ventilation.

Common Mistakes
Too often, builders install products that short-circuit their ventilation system. When designing a ventilation system, avoid these common pitfalls:

? Don't use a combination of different types of exhaust vents, like power vents with ridge vents. In this case, competing vents pull air from each other instead of soffit vents.

? Don't underestimate your ventilation needs. Remember that 15 roof vents or 5 turbine vents would be needed to provide the same ventilation as 42 feet of ridge vent.

? It is of no use to install exhaust vents without adequate intake. An effective balance of intake and exhaust must be achieved to properly ventilate the home. The flow of air in your attic is limited to the amount of intake.

Evaluate Your Needs for Ventilation
To specify an attic ventilation system, you should first determine the square footage of the attic. You'll need this figure to make sure you install adequate ventilation. If the roof pitch is 7/12 to 10/12, add 20% to your calculation for vent requirements; 30% for roof pitches of 11/12 and steeper.

Effective ventilation requires a balancing act. You want to "wash" the entire attic by pulling air from the soffits in the low areas to the vents at the ridge in the high areas.

For more information please contact us at info@affordableroofingfl.com.