Ridge Vents: A Guide to Essential Roof Ventilation

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Written by Brenda Woods Updated 03/25/2024

For a roof to function properly, air needs to circulate freely between the attic, roof decking, and outdoors, and precipitation must be kept out—which is where ridge vents come into play.

What Are Ridge Vents?

Ridge vents are low-profile ventilation systems installed along the peak of a sloped roof. These roof vents run the length of your roofline just below the peak and allow hot air and moisture to escape the attic. They play a crucial role in ensuring proper airflow within your attic, which is essential for moisture control, temperature regulation, and roof lifespan.

While there are a handful of roof vent systems available to consumers, ridge vents are particularly popular because they’re nearly invisible from the ground. They are often made of the same materials as your roof, which allows them to blend in seamlessly. It’s important to note that ridge vents are most effective on gable roofs with long ridge lines; other types of roofing, such as flat roofs, require a different solution.

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Understanding How Ridge Vents Work

Ridge vents are one part of a larger roof ventilation system that relies on convection, or the tendency of hot air to rise. Openings along the length of the ridge vent allow hot, humid air to escape the attic while cool, dry air enters through the soffit vents under the eaves. This passive ventilation creates a continuous circulation of air without the need for a fan.

On windy days, air blowing across the ridge creates a low-pressure zone that draws air out of the attic through the ridge vent. Wind isn’t necessary, though. Even on calm days, warm air will naturally rise and escape through the vents via convection.

Though ridge vents allow air to flow freely, they are designed to keep out rain, snow, and debris. They typically have baffles or mesh screens that prevent water and larger particles from entering the attic space.

Benefits of Ridge Vents

Here are some advantages ridge vents offer:

Improved Energy Efficiency

Proper attic ventilation keeps heat from building up in your attic, which reduces the strain on your HVAC system—especially during the summer. This translates to lower energy bills, a more comfortable home, and a longer-lasting HVAC system.

Extended Roof Lifespan

Ridge vents reduce stress on your roof by keeping the attic temperature close to the outside air. This minimizes harmful freeze-thaw cycles, prevents ice dam formation, and reduces the risk of shingle deterioration, extending how long your roof lasts and potentially saving you thousands on the cost of a new roof.

Prevention of Moisture Damage

Moisture that becomes trapped within the roofing system or the attic can become a breeding ground for mold and mildew, which can become toxic over time. Ridge vents promote better airflow, circulating damp, stale air outside and fresh air inside. This prevents condensation buildup on roofing materials and protects your home from costly mold remediation and structural repairs.

Better Indoor Air Quality

Not only do ridge vents expel hot air and moisture, but they also allow fresh air to circulate throughout your attic, leading to better overall air quality in your home. This can be especially beneficial for people with allergies or respiratory problems.

Ease of Installation and Maintenance

Most ridge vents are relatively easy to install, especially compared to other ventilation options. Additionally, they require minimal maintenance, typically just periodic cleaning of any debris buildup.

Relatively Low Cost

Compared to the potential damage they help prevent and the long-term benefits they offer, ridge vents are a relatively low-cost investment. Their affordability makes them a smart choice for any homeowner looking to improve their home’s health and efficiency.

Types of Ridge Vents

Most ridge vents fall into one of two design categories: shingle-over or exposed. Homeowners must also decide whether to invest in a baffled ridge vent or settle for an unbaffled version.

Shingle-Over vs. Exposed

Baffled vs. Unbaffled

Shingle-over ridge vents have a discreet design, covered by a layer of special ridge cap shingles that blend in with the rest of your roof. They require minimal roof cutting, which saves you money on installation. However, they may not be as effective or durable in high winds or on steep roofs.

Exposed ridge vents are typically made of finished aluminum and are not covered by any other roofing material. Though they are more visible than shingle-over vents, they are also sturdier and more effective. They typically cost more and require professional installation, but they provide better ventilation—particularly in windy areas or steep roofs.

Baffled ridge vents have a built-in shield, or baffle, that blocks windblown rain, snow, and debris while still allowing air to flow freely. Baffled ridge vents cost more but provide an extra layer of protection for your attic. They are especially beneficial in areas with harsh weather or homes with steeper roofs.

Unbaffled ridge vents have a minimalist design with no barrier to block windblown precipitation and debris. They allow for maximum airflow and have a lower price tag than baffled ridge vents, and they may be fine for mild climates and lower roofs. However, you may need to invest in additional weather protection.

Installation and Maintenance of Ridge Vents

While we recommend professional installation for roof vents, homeowners can play a role in properly maintaining them.

Installation Process

Ridge vents are sold by linear foot and can be purchased in most home improvement stores. Here are the steps a roofing contractor will follow to install a ridge vent:

Remove enough shingle caps and shingles on the roof’s peak to expose at least 3 inches of roof decking.
Cut an opening for ventilation in the decking along the peak.
Reattach the existing type of roof shingles to cover the exposed deck, adding new high-quality roofing shingles as necessary.
Place the ridge vent over the ventilation opening and nail it down on each side as instructed by the manufacturer.
Seal edges with caulk as recommended by the manufacturer.
Add any connectors or end caps that came with the ridge vent.
If using a shingle-over vent, reinstall shingle caps over the vent’s top.

Common Installation Mistakes to Avoid

Here are some common pitfalls and how to avoid them:

Not leaving a gap: Vent material will expand and contract slightly with temperature changes. Leave a gap of about 1/8 inch between sections to prevent buckling.
Crooked installation: Nail one side of the vent down the entire ridge’s length before moving to the other side. This will help ensure the vent forms a straight line.
Overdriving nails: Hammer carefully or use a nail gun with adjustable depth control and practice on scrap material to determine the right setting. Overdriving the nails can cause buckling, so make sure nail heads are flush with the vent surface.
Using the wrong nails: Use the nails included with the ridge vent, which are different from the nails used for regular shingles.
Poorly securing the ridge cap shingles: When installing ridge cap shingles, use two nails on either side of the shingle to protect against strong winds.

Maintenance Tips for Homeowners

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Regular professional inspections of your roofing and ridge vents will ensure a longer life. Homeowners should also inspect ridges for loose or damaged shingles, moss, or algae buildup. It’s important to keep the ridge vent free of obstructions such as leaves, debris, and ice to maintain proper ventilation. If debris buildup is a regular problem, consider trimming back nearby tree branches or hiring a roof cleaning company.

Removing moss from your roof is a relatively simple DIY project. If you decide to tackle this project yourself rather than paying for a professional roof cleaning, check out the video below first. General contractor Tom Silva helps a homeowner remove moss from his roof and install zinc strips near the ridge to prevent the moss from returning.

Comparing Ridge Vents With Other Roof Ventilation Systems

Ridge vents aren’t your only option for attic ventilation. Another system may be more effective depending on your roof type, attic shape, and climate.

Box Vents

Gable Vents

Power Vents

Like ridge vents, box vents are used in conjunction with soffit vents to create convection-based airflow. However, instead of one long vent, a box vent system includes a number of devices that a roofer installs along the ridge. A box vent may be square or round and may protrude slightly above the roof line. Box vents are more expensive than ridge vents because you need to cut through shingles and decking to install them. They’re better suited to low-slope or multi-ridged roofs.

Gable vents installed on opposing attic walls to allow for a cross breeze. Gable vents are less expensive to install than a combination of ridge and soffit vents. However, they’re susceptible to heavy rain and wind damage and aren’t suited for climates without regular breezes.

If your attic is a finished space complete with heating or cooling, passive ventilation won’t sufficiently maintain airflow, and you’ll need to keep the area as insulated as other living spaces. You’ll likely need active mechanical ventilation in the form of a fan or power vent. This system costs more to install and run than a passive system, but it ensures ventilation no matter the temperature.

How To Hire a Pro

Your home’s roof is a complicated system. We recommend hiring a licensed roofing company to get the best results and maintain your roof’s warranty. Here’s what to look for when choosing a professional roofer:

Anyone who does work on your house should be bonded and insured.

Check the company’s Better Business Bureau page and customer reviews on sites such as Trustpilot. Ask for references from previous customers.

Get quotes from at least three local contractors. When possible, get an itemized estimate so you know where your money is going.

In nearly all states, professional roofers must have the specialized training and experience to earn and maintain a roofing license.

Make sure you understand the timelines for both the project and payment.

Our Conclusion

While ridge vents are not recommended for all roof styles or all climates, they help eligible households ventilate attic space and lengthen a roof’s lifespan while cutting down on energy costs. Further, ridge vents keep attics free of moisture and roof repair expenses down.

Ridge vents work best on simple, single-ridge roofs with a moderate pitch. If you have a steep or complex roof, other vent types may be more effective. You should also consider the climate. If you live in an area with lots of wind, rain, or snow, your roof may need additional protection. A professional roofer can help you determine the best solution for your home.

FAQ About Ridge Vents

How many ridge vents do I need for my roof?

According to the Federal Housing Administration (FHA), you need 1 square foot of ventilation for every 300 square feet of attic space. You can find attic ventilation calculators online to estimate how many ridge vents you need for your roof.

Can ridge vents be installed on an existing roof?

Ridge vents can be installed on an existing roof and are often easier to install than other vents.

Are ridge vents weatherproof?

No ridge vent is completely weatherproof. However, ridge vents with baffles keep out precipitation, debris, and insects more effectively than those without baffles.

What are the signs of inadequate attic ventilation?

Here are some signs that your attic has inadequate ventilation:

Cracked or blistering shingles
Excessive heat
Ice dams in the winter
Mold, mildew, or discoloration on building materials
Respiratory problems or allergy attacks
Visible condensation or moisture

Can ridge vents help reduce energy costs?

Yes, ridge vents can help reduce energy costs. Proper ventilation helps regulate the temperature in your attic, which in turn reduces heating and cooling costs.

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