Effective attic ventilation is critical
for a long-lasting roof!
A properly balanced attic ventilation system will help to:
Cobra® Exhaust Vent is a key part of the GAF Lifetime Roofing System,
and has even earned the prestigious Good Housekeeping Seal (U.S. only).
(See Details)
* The GAF Lifetime Roofing System has earned the prestigious Good Housekeeping Seal (U.S. only), which means that Good
Housekeeping stands behind the products in this system. (Refer to Good Housekeeping Magazine for its consumer
protection policy. Applicable in U.S. only.)
Florida Building Code
ICC-ES ESR 1265
Balanced ventilation requires an equal amount of intake ventilation and exhaust ventilation. GAF recommends, at a minimum, providing 1 square foot of Net Free Ventilation for every 300 square feet of attic floor space. Consult local building codes for specific ventilation requirements in your area.
How Much Do I Need? (Based on 1/300 Rule)
|
||
Total Attic
Square Footage |
Recommended Length of
Cobra® Exhaust Vent (Feet)* |
Minimum Intake Ventilation
(Net Free Area in Sq. In.)* |
1600
|
23/28
|
389/395
|
1900
|
27/33
|
457/466
|
2200
|
32/38
|
541/536
|
2500
|
36/43
|
609/607
|
2800
|
40/48
|
676/677
|
3100
|
45/53
|
761/748
|
3400
|
49/58
|
829/818
|
*First figure pertains to hand nail, second figure pertains to nail gun.
NOTE: Always have a balanced ventilation system. In no case should
the amount of exhaust ventilation at the ridge exceed the amount of soffit ventilation.
All documents are U.S. English unless otherwise noted
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