GAF Attic Ventilation, Roof Vents

Cobra® Attic Ventilation

Cobra Exhaust Vent
Cobra® Exhaust Vent

The original Cobra® Ridge Vent — protects over 2 million homes!

Cobra Ridge Runner Cobra®
Ridge Runner®
(Attic Exhaust Vent)

The performance of a baffled rigid vent... with the ease of a roll!

Cobra Snow Country Advanced Cobra® Snow
Country™ Advanced
(Attic Exhaust Vent)

Premium quality rigid-style vent. Snow Guard filter helps resist snow infiltration. Includes 3" ring shank nails for easy installation. Available in colder climates.

Cobra Hip Vent Cobra® Hip Vent (Attic Exhaust Vent)

Safe and effective exhaust ventilation for homes with little or no ridge.

Cobra FasciaFlow Vent Cobra® IntakePro (Attic Intake Vent)

Allows you to add attic intake ventilation when you have no soffits.

Master Flow® Attic Ventilation & Accessory Products

(not covered under Lifetime Roofing System Warranty)

Master Flow Roof Louvers Master Flow®
Roof Louvers
(Attic Exhaust Vents)

A complete line of quality options for those who prefer roof louvers (or where existing roof louvers are being replaced).

MasterFlow Solar-Powered Roof  Vent Master Flow® Green Machine™ High-Power Solar Roof Vent – Available in Solar & Dual-Powered Models (Attic Exhaust Vent)

Helping to reduce attic cooling costs, this next generation vent combines increased airflow with excellent aesthetics

MasterFlow Solar-Powered Roof exhaust Vent Master Flow®
Green Machine™
Solar-Powered EcoSmart Roof Vent
(Attic Exhaust Vent)

Removes damaging heat and moisture from your attic... without the need for an electrical connection.

Master Flow Power Roof Ventilators Master Flow®
Power Attic Ventilators - Roof Mount
(Attic Exhaust Vents)

Help exhaust the greatest volume of hot and/or humid air from the attic vs. conventional attic exhaust vents.

Master Flow Power Gable Ventilators Master Flow®
Power Attic Ventilators - Gable Mount
(Attic Exhaust Vents)

Typically the easiest power vents to install and will not detract from the look of the finished roof.

Master Flow Rotary Turbine Vents Master Flow®
Rotary Turbine Vents
(Attic Exhaust Vents)

Designed with upper and lower stainless steel bearing systems for years of trouble-free operation on the roof.

Master Flow Green Machine Dual Powered Master Flow®
Green Machine™
Dual-Powered EcoSmart Roof Vent
(Attic Exhaust Vent)

Removes damaging heat and moisture from your attic whether the sun is out or not!

Master Flow Solar Powered Roof Intake Booster Master Flow®
Green Machine™
EcoSmart Ridge Vent
(Attic Exhaust Vent)

Provides increased airflow over typical ridge vents, turbines, and roof louvers to help reduce hot or moist air in your attic.

Master Flow Aluminum Ridge Vents Master Flow®
10' Aluminum
Ridge Vent
(Attic Exhaust Vent)

Made of durable aluminum construction with built-in baffle for reliable performance on the roof.

Master Flow Soffit/Undereave Vents Master Flow®
Soffit/Undereave Vent
(Attic Intake Vent)

Easy-to-install options for providing critical attic intake ventilation at the soffit or undereave areas of the roof.

Master Flow EmberShield Master Flow® EmberShield® Closeable Soffit Vent (Attic Intake Vent)

Helps prevent wildfire embers from being drawn into the attic.

Master Flow Solar Powered Roof Intake Booster Master Flow®
Green Machine™
Solar-Powered Intake Booster Vent
(Attic Intake Vent)

Perfect for houses with insufficient soffit ventilation.  Installs without an electrical connection.

Master Flow Gable Louver Master Flow®
Gable Louvers
(Intake or Exhaust Vents)

Flush and recessed-mount vents for gable wall and other hard-to-ventilate areas.

Master Flow Foundation Vents Master Flow® Foundation Vents (Foundation/Crawl Space Vents)

Solutions to help remove damaging moisture from the foundation area of the home.

Master Flow Whole House Fans Master Flow®
House Fans

Smart energy savers for any climate where air conditioning costs are a concern.

MasterFlow Chimney/Roof Caps & Other Accessories Master Flow®
Roof Caps & Other Accessories

A wide array of goose neck vents, roof caps, jacks, and flashings, as well as moss and mildew preventers and other accessories.

Master Flow Safety Caps for Chimneys Master Flow® Safety Caps
for Chimneys

Provide protection against dangerous sparks while reducing downdrafts, clogging, soot, and creosote build-up.

Poor Attic Ventilation Can Ruin Your Insulation, Destroy Your Shingles, And Potentially Raise Your Energy Bills!

Proper Attic Ventilation

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 .

Why Take Risks?

Many 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.

Types of damage that can result include:

  • Premature aging of your roofing system ("fried" shingles)
  • Warping, cracking, or breaking down of wood framing
  • Damage to siding, exterior or interior paint, and wallpaper

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.

Additional structural damage can include:
  • Roof deck warping and rotting of the wood frame
  • Mildew growth
  • Buckling of shingles and felt

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:

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 # 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.

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