Product Brochure

Cobra
®
is one of the most trusted brands in attic ventilation...
protecting millions of homes since 1991! Offering a wide array of
high-performance ridge and intake venting solutions for virtually any
climate, Cobra
®
products are designed with the contractor in mind.
From the unique EasyTear
™
Sizing Feature (available on Cobra
®
plastic vents) to the Smart Nail
™
Fasteners (available on Cobra
®
Exhaust Vent), Cobra
®
products help ensure a fast, easy installa-
tion. Cobra
®
Attic Ventilation Products are part of the GAF Lifetime
Roofing System and are covered by up to a Lifetime ltd. Warranty.*
They’ve even earned the Good Housekeeping Seal!**
A leading brand in the roofing industry for off-ridge ventilation...
Master Flow
®
Attic Ventilation includes a complete line of roof
louvers, turbines, intake vents, electric vents, and innovative
Green Machine
™
solar-powered vents. From extra-wide nailing
flanges and pre-drilled fastener holes to 100% factory-tested motors,
contractors and property owners alike can be confident in their
long-term performance and reliability. Plus, they’re backed by GAF,
North America’s Largest Roofing Manufacturer, and have also
earned the Good Housekeeping Seal!**
** Cobra
®
and Master Flow
®
Attic Ventilation products have
earned the prestigious Good Housekeeping Seal, which
means that Good Housekeeping stands behind these
products. (Refer to Good Housekeeping Magazine for
its consumer protection policy. Applicable in U.S. only.)
iness Practice
Step 1 Calculate attic square footage
How: Multiply length of attic (in feet) times width of
attic (in feet)
30' x 40' = 1,200 square feet
Step 2 Calculate NFA (Net Free Area) needed for this attic by
using the "1 in 300" rule
How: Divide attic square footage by 300
1,200 sq. ft. ÷ 300 = 4 square feet of NFA needed
Step 3 Convert square feet of NFA to square inches
How: Multiply square feet of NFA by 144
4 sq. ft. x 144 = 576 square inches of NFA needed
Step 4 Split the amount of NFA needed equally between the
intake and the exhaust
How: Divide square inches of NFA needed by 2
576 sq. in. ÷ 2 = 288 square inches of NFA
needed equally for exhaust & intake
Step 5 Calculate number of feet of Cobra
®
Exhaust Vent
(Hand Nail)
How: Divide the square inches of NFA needed at
the ridge by the NFA of the Cobra
®
Exhaust Vent
(Cobra
®
Exhaust Vent is 16.9 sq. inches of NFA
per lineal foot)
288 sq. in. ÷ 16.9 = 17 lineal feet
This attic requires 17 lineal feet of Cobra
®
Exhaust Vent to meet
the “1/300” attic ventilation rule
Calculating How Much Ventilation to Install:
*
Remember: Always have a balanced ventilation system. In no case
should the amount of exhaust ventilation exceed the amount of
intake ventilation.
* Calculations are based on 1 square foot of net free ventilating opening for every 300 square feet
of insulated ceiling with a vapor barrier. Some building codes require 1:150 if there is no vapor
barrier. Always consult local building codes for other ventilation requirements.
Example: Calculating the number of lineal feet of Cobra
®
Exhaust
Vent (Hand Nail) needed for a 30’ x 40’ attic:
Attic
Ventilation Calculator
3
®
* See GAF Shingle & Accessory Ltd. Warranty for complete coverage and restrictions. The
word “Lifetime” refers to the length of coverage provided by the GAF Shingle & Accessory Ltd.
Warranty and means as long as the original individual owner(s) of a single-family detached
residence [or the second owner(s) in certain circumstances] owns the property where the shin-
gles and accessories are installed. For owners/structures not meeting the above criteria, Lifetime
coverage is not applicable. Lifetime ltd. warranty on accessories requires the use of at least three
qualifying GAF accessories and the use of Lifetime Shingles.
Visit gaf.com/VentCalculator
to calculate the amount of
Cobra
®
and Master Flow
®
Vents
needed for your next job!