The original Cobra® Ridge Vent — protects over 2 million homes!
The performance of a baffled rigid vent... with the ease of a roll!
Premium quality rigid-style vent. Snow Guard™ filter helps resist snow infiltration. Includes 3" ring shank nails for easy installation. Available in colder climates.
Safe and effective exhaust ventilation for homes with little or no ridge.
Allows you to add attic intake ventilation when you have no soffits.
For those who prefer roof louvers or where existing louvers are being replaced.
Helping to reduce attic cooling costs, this next generation vent combines increased airflow with excellent aesthetics
Removes damaging heat and moisture from your attic... without the need for an electrical connection.
Master Flow® Power Ventilators are your best overall investment in attic ventilation.
Gable mount attic ventilators are the easiest power vent to install.
Deluxe turbines are designed with upper and lower stainless steel ball-bearing systems for years of trouble-free operation.
Removes damaging heat and moisture from your attic whether the sun is out or not!
Provide increased airflow over typical ridge vents, turbines, and roof louvers to help reduce hot or moist air in your attic.
Quality-built for long life on the roof.
Perfect for houses with insufficient soffit ventilation.
Perfect for houses with insufficient soffit ventilation. Installs without an electrical connection.
Designed for flush or recessed installation.
Remove damaging moisture – help prevent structural decay and mold growth.
Smart energy savers for any climate where air conditioning costs are a concern.
Press sealed design for maximum leak protection.
Provide protection against dangerous sparks while reducing downdrafts, clogging, soot, and creosote build-up.
Proper attic ventilation systems allow a continual flow of outside air through the attic, protecting the efficiency of the insulation and helping to lower temperatures in the living space.
It consists of a balance between air intake (at your eaves or soffits) and air exhaust (at or near your roof ridge).
The U.S. FHA (Federal Housing Administration) recommends a minimum of at least 1 square foot of attic ventilation (both intake and exhaust) for every 300 square feet of attic space. For example, if your attic is 900 square feet, you need a total of 3 square feet of ventilation. This amount should be divided equally between intake and exhaust ventilation (i.e., 1 1/2 feet of each) to insure proper air flow through the attic. To calculate the amount of ventilation you need for your home, visit GAF's Ventilation Calculator .
It is estimated that 9 out of 10 homes in North America do not have proper attic ventilation. Why? Because most people are unaware that attic ventilation can impact the longevity of their entire home!--
In the summer, improper ventilation can cause attic heat to build in excess of 160°F. This super-heated air eventually penetrates the ceiling insulation into the living area below.
A properly ventilated attic can help reduce the load on your air conditioner by
moving the super-heated air out of your attic before it builds up and causes damage.
In the winter, various household appliances, bathtubs, showers, and cooking vapors can contribute to excess moisture build-up. Improperly ventilated attics will allow this moisture to collect and cling to the underside of the roof. The moisture will condense and fall, soaking the attic insulation and reducing its efficiency.
Finally, attics should be properly ventilated to help prevent ice dams in cold northern climates. During the winter, ice and snow on a roof will melt and run down the deck to the cooler eaves. This run-off can re-freeze, creating an ice dam that may force water back up under the shingles and leak into your home — causing hundreds or thousands of dollars of damage to your ceilings and walls. Adequate attic ventilation reduces the amount of initial melting that occurs on your roof, thereby reducing the chance that ice dams will form.
Calculating Your Ventilation Requirements
Example: Calculating the number of linear feet of Cobra® Exhaust Vent needed for a 30"x 40" attic:
Calculate attic square footage
How: Multiply length of attic (in feet) times width of attic (in feet)
30" x 40" = 1,200 square feet
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
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
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
Calculate # of linear feet of Cobra® Exhaust Vent
How: Divide the square inches of NFA needed at the ridge by the NFA of the Cobra® Exhaust Vent (Cobra® Exhaust Vent has 16.9 sq. inches of NFA per linear foot)
288 sq. in. ÷ 16.9 = 17 linear feet
This attic requires 17 linear feet of Cobra® Exhaust Vent to meet FHA minimum requirement
Intake ventilation MUST be at least equal to exhaust ventilation.
To determine the number of intake vents needed, install enough vents so that their combined NFA is at least 300 square inches.
Always have a balanced ventilation system. In no case should the amount of exhaust ventilation exceed the amount of intake ventilation.