RoofViews

Your Home

The Most Common Types of Roof Vents for Attic Ventilation

By Wendy Helfenbaum

August 03, 2021

types of roof vents

Roof vents form the base of your attic ventilation system. They let your attic breathe—and they help protect your roof system from damaging heat and moisture.

Here's how two important types of roof vents work and what benefits they can bring your house.

What Products Do I Need for an Effective Attic Ventilation System?

An attic ventilation system consists of intake vents and exhaust vents. Together, these products can be used to create a balanced attic ventilation system that helps to reduce attic temperature and excess moisture.

Intake vents, located at or near the bottom of your roof, are a very important part of your attic ventilation system. These vents allow fresh air from outside into the attic. If there's no air coming in, then no air can flow out, reducing the effectiveness of the attic ventilation system and potentially causing roof system degradation.

This air current continually flows through the attic and then back outside through exhaust vents positioned at or near the top of your roof. The vents help protect the roof system from the inside out. It's important that the amount of exhaust ventilation at or near the ridge does not exceed the intake air ventilation at or near the soffit.

Types of Intake Vents

There are two types of intake vents: soffit vents and rooftop intake vents. Most homes have soffit vents if they are constructed with roof overhangs or eaves. Because the soffit is typically located at the lowest point of the roof, it's in the perfect spot for fresh air to enter the attic. Soffit vents come in various styles, including individual vents, continuous strips, and ventilated soffit panels.

Homes with limited or no soffits can use rooftop intake vents, which do not require homeowners to build expensive new soffits or alter existing ones.

Choosing Exhaust Vents for Your Attic Ventilation System

Exhaust ventilation is most efficient when it's installed at or near the highest point of your roof where hot, humid air can easily escape. Exhaust vents are divided into three common categories: static, powered, and mechanical.

1. Static Exhaust Vents

Since they make use of the natural flow of air as hot air rises, static exhaust vents do not require electricity.

Different Types of Vents

There are three types of static exhaust vents:

  1. Ridge vents: These are installed on most homes, since this type of exhaust vent is effective and fairly easy to install at the highest point of the roof: the ridge or peak. It's the ideal location to allow hot air to escape the attic. Ridge vents also blend in with the finished roof thanks to their low profile. They are covered by ridge cap shingles.

  2. Hip vents: Hip vents are similar to ridge vents in both design and function. They help ventilate homes with hip roof designs that have very limited or no ridge area. To provide a uniform appearance, the hip vents themselves are typically installed along the entire length of the hip, while the air slots underneath the hip vents are located only at the top portion of the hip. Depending on the design of your roof, hip vents can also be combined with ridge vents to provide the amount of exhaust your attic needs.

  3. Roof louvers: Also known as box vents, roof louvers offer another exhaust vent option for modern roof designs, hip roofs, smaller roof areas, and those with limited or no ridge line. In order to achieve the proper amount of exhaust ventilation, roof louvers usually require the installation of multiple vents due to their small size. However, the louvers can be installed on the back portion of the roof for a streamlined appearance. They can be installed on both existing or new roofs.

2. Powered Exhaust Vents

Powered exhaust vents help remove a large volume of warm, humid air from the attic. Powered by electric, solar, or a combination of both, often referred to as dual-powered or hybrid, these vents have different cubic feet per minute (CFM) airflow ratings: the higher the CFM airflow, the faster the vent exhausts air out of the attic. Powered vents typically include thermostat control with some models available with an optional humidistat/thermostat control.

Powered Exhaust Vents

There are two common types of powered exhaust vents:

  1. Roof-mounted: In electric, solar or dual-powered options, these exhaust vents are installed over the openings in the roof deck.

  2. Gable-mounted: This type of exhaust vent can be easily installed from inside the attic, which helps avoid roof penetration.

3. Mechanical Exhaust Vents

Mechanical

Mechanical exhaust vents such as wind turbines harness the power of the wind to help remove excess heat and moisture from the attic. With enough wind, the turbine spins and pulls heat and moisture from the attic. Turbines sit higher above the roof surface, so they stand out more than other exhaust options, but they move air effectively. When there's no wind, their function is similar to that of a static exhaust vent.

Which Types of Roof Vents are Best for my Home?

Every home is different. The best vents for your roof will depend on your home's architectural style, the design of your roof, and your local climate. It's important not to mix different types of exhaust vents in the same attic space, which can prevent proper airflow through the space.

A qualified roofing professional can implement a balanced attic ventilation system of intake and exhaust vents that will help reduce excess heat and moisture from your attic. To help calculate your attic's ventilation needs, click here or contact a contractor certified by GAF* near you.


* Contractors enrolled in GAF certification programs are not employees or agents of GAF, and GAF does not control or otherwise supervise these independent businesses. Contractors may receive benefits, such as loyalty rewards points and discounts on marketing tools from GAF for participating in the program and offering GAF enhanced warranties, which require the use of a minimum amount of GAF products.

About the Author

Wendy Helfenbaum is a Montreal-based journalist, content marketing writer and TV producer who covers design, architecture, real estate, gardening and travel for many publications and brands, including Country Gardens, Metropolis Magazine, Realtor.com, Marriott Traveler, Costco Connection, Toll Brothers, PBS NextAvenue.org and many more. Wendy loves keeping up with current design trends and is addicted to home improvement DIY reality shows. Follow her @WendyHelfenbaum.

Related Articles

GAF Timberline HDZ Reflector Series Shingles on a roof.
Residential Roofing

Timberline HDZ® Reflector Series Shingles: A New Era in Reflective Shingles

GAF Timberline HDZ® Reflector Series Shingles come in rich, vibrant colors, giving homeowners attractive color options that can be used to comply with the Cool Roof Requirements of Title 24 and the LA County Green Building Standards Code.*Here's why you may want to add these shingles to your business offerings, especially if you work in California.Timberline HDZ® RS ShinglesA few features make these shingles stand out.Meeting California Code ComplianceIn California, residential roofs must meet solar reflectance requirements because they are mandated by California's Building Energy Efficiency Standards Title 24, Part 6 and Los Angeles County Green Building Code. Both codes set a minimum reflectance rating known as the solar reflective index (SRI), which measures a material's ability to reflect sunlight and heat. The lower the SRI value (from 0 to 100), the hotter a material becomes in sunlight. The higher the value, the cooler the material. Shingles with a higher SRI help reduce temperatures by reflecting sunlight which can help reduce the cooling load.The new Timberline HDZ® RS Shingles provide solar reflectance that complies with both Title 24 and the Los Angeles County Green Building Code.Title 24California's Title 24 covers the entire state, unless local requirements are stricter, providing cool roof requirements for residential and commercial buildings based on their locations within 16 climate zones. For residential buildings (new construction), climate zones 1 through 9 and 16 have no cool roof requirements. Climate zones 4, and 8 through 15 require cool roofs for new and reroof applications when more than 50% of the roof is removed.If shingles don't meet the required SRI, alternative paths to compliance include using a radiant barrier, airspace, or additional attic insulation.Los Angeles County Green Building CodeThe Los Angeles County Green Building Code's Cool Roof Ordinance covers buildings in the county and prescribes SRI values depending on the type of building (low-rise residential, high-rise residential and hotels/motels, and nonresidential) and roof slope. High-slope (more than 2:12), low-rise residential roofs must have an SRI of 20 or more. Exceptions apply to roof repairs or replacements where less than 50% of the roof is removed, additions of less than 500 square feet or less than 50% of the total roof area, and green roofs.Selling Points for California HomeownersWhen working with property owners in California and Los Angeles County, you can highlight the following selling points of Timberline HDZ® Reflector Series Shingles.Potential Savings on Cooling CostsReflective roofing may help decrease a roof's temperature and cooling load, which has the potential to lower cooling costs.****StyleTimberline HDZ® RS Shingles provide the darkest highly-reflective shingle available, Charcoal, thanks to EcoDark® granules. They also feature GAF's High Definition® color blends for dimensional, wood-shake look.Peace of MindHomeowners can enjoy heightened confidence when choosing Timberline HDZ® RS Shingles because they come with a Lifetime Limited Warranty***** against manufacturing defects and a 25-year StainGuard Plus™ Algae Protection limited warranty.**Enhancing Homes' AppealHomeowners can rest assured that the new Timberline HDZ® Reflector Series Shingles offer the durability of GAF shingles while providing deep, rich color options to match their unique aesthetic.Color OptionsTimberline HDZ® RS shingles feature newly formulated EcoDark® Granules that provide deep rich, dark colors including Charcoal, the darkest highly-reflective shingle color in California, as well as other popular shingle colors that offer color blends for a more dimensional look.Time-Release Algae Fighting TechnologyTimberline HDZ® RS shingles feature GAF Time-Release Algae-Fighting Technology which uses specially engineered capsules that are infused with thousands of copper microsites. This allows the copper to release steadily over time for long-lasting algae fighting power. It's technology so strong, it powers the 25-Year StainGuard Plus™ Algae Protection Limited Warranty.**WindProven Limited Wind WarrantyTimberline HDZ® RS shingles have LayerLock® technology and the StrikeZone™, nailing area like traditional Timberline HDZ® shingles, and are eligible for the WindProven™ Limited Wind Warranty with no maximum wind speed limitation when installed with the required combination of accessories.***Curious to learn more? Visit the GAF Timberline HDZ® RS Shingles product page for more details.*Can be used to comply with the Cool Roof Requirements for steep slope residential buildings of 2022 Title 24, Part 6, of the California Code of Regulations and the Green Building Standards Code of Los Angeles County.**25-year StainGuard Plus Algae Protection Limited Warranty against blue-green algae discoloration is available only on products sold in packages bearing the StainGuard Plus logo. See GAF Shingle and Accessory Limited Warranty for complete coverage and restrictions.***15-year WindProven™ limited wind warranty covers GAF Shingles with LayerLock® Technology only and requires the use of GAF Starter Strips, Roof Deck Protection, Ridge Cap Shingles, and Leak Barrier or Attic Ventilation. See GAF Roofing System Limited Warranty for complete coverage and restrictions. Visit gaf.com/LRS for qualifying GAF products. For installations not eligible for the WindProven limited wind warranty, see GAF Shingle & Accessory Limited Warranty for complete coverage and restrictions.****Energy cost savings are not guaranteed and the amount of savings may vary based on a variety of factors, such as climate zone, utility rates, radiative properties of roofing products, insulation levels and HVAC equipment efficiency.*****Definition of Lifetime: The word "Lifetime" means as long as you, the original owner(s) [or the second owner(s) if coverage was properly transferred during the Smart Choice Protection Period], own the property where the shingles and/or accessories are installed. The Lifetime warranty is applicable only to shingles and accessories installed on a single-family detached residence owned by individuals. For any other type of owner or building, such as a corporation, governmental entity, religious entity, condominium or homeowner association, school, apartment building, office building, or multi-use structure, the length of the warranty is 40 years. See the GAF Shingle & Accessory Limited Warranty, GAF Roofing System Limited Warranty and GAF Golden Pledge Limited Warranty for complete coverage and restrictions.

By Authors Dawn Killough

September 06, 2024

Contractor on a roof install with workers
Your Home

What to Look for When Finding a Contractor

Your roof is a long-term investment that helps protect your family, may improve your home's resale value, and crowns your home's aesthetic so finding a contractor that is qualified is very important. To help you choose a roofing contractor with confidence, here are three qualities to look for.1. Professional Experience and ReputationBefore you hire, do your research. Choose a company based on experience and reputation—not just price. If you decide on price alone, you may not be making the best choice.RecommendationsWord-of-mouth from trusted sources is a great starting place. Ask neighbors, friends, and online community forums for referrals.ResearchVisit the company's website to determine the products and services it offers—as well as the number of years it's been in business. Then, verify the company is licensed and insured.ReviewsNext, read reviews from multiple online platforms to learn about customer experiences. Resources could include Google Reviews, Yelp, Better Business Bureau, and the company's social media pages. While searching, look for info such as ease of interactions, professionalism during installation, cleanup after project completion, and overall satisfaction with the outcome.2. CertificationsFinding a contractor certified by a manufacturer typically indicates that a contractor has met the certification requirements of the manufacturer. For example, contractors certified by GAF must be insured and licensed in states where they operate (if required). GAF also considers factors such as years of roofing experience, credit rating and overall standing with the Better Business Bureau.Higher tiers of certification may be allowed to offer better enhanced warranties on qualifying roofing systems. For example GAF Master Elite® Contractors are entrusted to offer the GAF Golden Pledge Limited Warranty* on qualifying roofing systems, which provides up to 30 years of misapplication coverage.VerificationVerify contractor certifications whenever possible. For example, the GAF website lets you verify whether a company is certified by GAF by simply entering their phone number or contractor ID.AwardsIn addition to certifications, select contractors may also qualify for manufacturer awards. For example, the highest distinction a GAF Master Elite® contractor can earn is the GAF's President's Club Award. This award indicates that a contractor has demonstrated commitment to installing GAF roofing systems backed by GAF's strongest warranties and dedication to learning about GAF's products and services.3. Operational ApproachAfter identifying several contractors, consider these talking points when interviewing the contractors:ExperienceAsk the contractor whether it has experience installing roofs on the type of roof architecture you have.AvailabilityWhen do you need the project to start, and when can the company actually do the installation? If your roofing needs are urgent (leaks, damage, etc.), make sure they can perform the work in the timeframe you are looking for.EstimateAsk the contractor to provide you with an estimate. As a preliminary step, try using GAF's estimate tool. However, keep in mind that the estimate provided by the tool is non-binding and contractors will provide their own estimates. Review actual estimates from contractors closely to understand what is included. The cheapest option is not always the best. Consider experience, and reputation, too.Payment OptionsAsk your contractor about payment options, including payment and financing options to make sure you choose the best option for you.Starting Your SearchPrioritizing these qualities when looking for a contractor may help you find the right company for the job.Are you ready for a new roof? Find a GAF certified roofing contractor** today.*See GAF Golden Pledge Limited Warranty for complete coverage and restrictions.**Contractors enrolled in GAF certification programs are not employees or agents of GAF, and GAF does not control or otherwise supervise these independent businesses. Contractors may receive benefits, such as loyalty rewards points and discounts on marketing tools from GAF for participating in the program and offering GAF enhanced warranties, which require the use of a minimum amount of GAF products. Your dealings with a Contractor, and any services they provide to you, are subject to the GAF Contractor Terms of Use.

By Authors Annie Crawford

August 20, 2024

A roofer installs GAF's Cobra SnowCountry Advanced Premium Exhaust Vent on a Roof Ridge
Residential Roofing

The Role of Roofing Codes and Standards in Roof Venting Product Development

When developing a new roofing product, it's important to ensure it meets the local roofing codes and requirements in multiple jurisdictions. These standards are often regionally similar, but some may require additional testing or the use of certain raw materials. The product development team at GAF works hard to ensure products meet some of the strictest codes, so they can provide years of protection no matter where they're installed.Jeremiah Hershberger, GAF product manager of residential accessories, recently discussed the role codes and standards play in residential roofing product development, specifically concerning roof vent code requirements.Why Are Product Codes and Standards Important?The main purpose of building codes and standards is to maintain public health, safety, and welfare in all structures. They do this by ensuring that buildings are constructed in such a way as to minimize potential hazards, like fire, structural failure, or storm damage.Building codes exist to improve the safety and livability of buildings. They set minimum requirements for the materials and systems installed, as well as their installation methods. In the US, building codes are upheld and enforced by state, county, and city governments through the permitting and inspection processes.Standards also provide minimum design and performance metrics for products and systems. However, unlike local building codes, they are often universally upheld (nationally or worldwide). Organizations like ASTM International and the National Fire Protection Association are responsible for creating, updating, and communicating these standards. Local building codes often use these standards to set minimums for product and installation quality.How Do Roofing Codes and Standards Affect Product Development?"The goal of product development at GAF is to provide enhanced value for our customers and contractors," Hershberger explains. Ultimately, customers need to be confident in the performance of GAF products and building codes and standards provide a minimum threshold for product performance. Accordingly, they must be taken into consideration when designing products.Codes are prescriptive performance requirements for buildings. They include both the materials used to construct the building and how they're installed. All products used in a particular building must meet the local code requirements for that county or city.Standards are used as bases of comparison. Types of standards include:Testing standards that define methods and minimum acceptable resultsRating standards that provide a way to fairly compare productsDesign standards that set the criteria for specific roof system designsWhen products are developed for use in many geographic areas, they must meet several locations' requirements. For instance, when developing a new off-ridge ventilation product, GAF considers not only how much net free area (NFA) the unit will have, but also the performance characteristics required to meet Florida Building Code, Texas Department of Insurance (TDI), and Miami-Dade standards so the product can be used in areas that adhere to those codes.Why Does GAF Pay Attention to Codes and Requirements?"We want our customers to be confident in the performance of our products not based solely on our word but also on the basis of third-party standards that level set the industry," notes Hershberger. "Codes and testing requirements provide customers with that outside assurance that our products will hold up to the environmental rigors of a specific region or location."For example, TAS-100(A) tests a product's performance in wind-driven rain. The test provides information on how well a ventilation product will perform in such an environment and helps the product development team learn how likely it is that a ventilation product might leak, so we can then mitigate that risk.How Do Codes Affect Product Quality?Codes may specify what raw materials can be used to make a product or how it will perform in certain standardized tests. For instance, ASTM E108 or ANSI/UL790 Class A roofing fire ratings require a high degree of fire protection to the roof deck, which directly affect the materials used to produce these products. Similarly, the UL 2218 Class 4 impact test or the ASTM E330 Uplift Pressure Test show how a product performs under naturally occurring forces (e.g., hail or wind)"GAF strives to find the balance between performance, strength, and ease of installation (or handleability)," Hershberger says. "This often leads us to develop products that use higher grade materials (better performance over time), are simpler to manufacture with fewer points of potential failure, and are easier to install correctly (ensuring repeatability)."How Codes Affect the Development of High-Quality Roof VentsCreating high-quality roof vents and rooftop accessories didn't occur by accident. The GAF development team focuses on roofing codes and requirements through an intentional design process to drive innovation. From product ideation to design, development, and launch, the team ensures products meet or exceed several codes and standards, including:Florida Building CodeSets minimum performance standards for roof construction, such as wind resistance, fire performance, and roof ventilation requirements. Products must be approved by the state before being installed.Miami-Dade CountyThis county in Florida has some of the strictest building codes in the country due to its classification as a High-Velocity Hurricane Zone. Products used there must also be approved by the county as meeting not only Florida Building Code, but the stricter county requirements.Texas Department of Insurance (TDI)Regulates insurance companies and the insurance/claims process in the state of Texas. Roofing products are evaluated based on TDI-adopted building specifications regarding products used and installation methods.Other tests performed to ensure product performance include:TAS-100(A). Determines the water infiltration resistance of a ridge area ventilation system (ridge vents, static vents, turbines, or powered vents).Simulated snow/ice dam. Ice dams can form when a roof is not properly ventilated, leading to snow melting and refreezing along the lower edge of the roof.UL2218 Class 4 impact test. The UL2218 test is a steel ball drop test that evaluates the impact resistance of roof coverings. Class 4 products are shown to withstand the 20-ft drop of a 2-inch diameter steel ball without cracking through significant damage.Ensuring Roofing Products Are Up to the TaskThe product team at GAF routinely performs these tests to ensure roofing materials meet local roofing code requirements. The company then makes the results publicly available, helping customers nationwide rest assured that they can rely on GAF roofing products to perform as expected.For more information on the GAF ventilation products that meet or exceed code requirements, explore the ridge and off-ridge ventilation offerings.

By Authors Dawn Killough

August 15, 2024

Don't miss another GAF RoofViews post!

Subscribe now