Should you use Ridge Vents on your Roof

For a roof to function properly, air needs to circulate freely between the attic, roof decking, and outdoors and precipitation must be kept out—ridge vents help on both fronts. The devices are often made of the same materials as your roof. Roof vents run the length of your roofline just below the peak and allow hot air and moisture to escape the attic. 

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. It’s important to note that gable roofs with long ridge lines are good candidates for ridge vents; other types of roofing, such as flat roofs, are not.

Ridge vents are one part of a larger roof ventilation system that relies on convection, or the tendency of hot air to rise, to function. When hot, humid air escapes the attic through the ridge vents, it allows cool, dry air to enter through rafter or soffit vents at the eaves. This creates passive ventilation that happens automatically without the need for a fan. 

Here are some advantages ridge vents offer:

Improved Energy Efficiency

Proper attic ventilation through ridge vents can help extend how long a roof lasts by keeping your attic cool and reducing strain on your HVAC system, lowering energy bills. In colder climates, a properly insulated ceiling and attic means less work for your furnace. 

Prevention of Moisture Damage

Moisture that becomes trapped within the roofing system or the attic will likely create mold and mildew that can become toxic over time and pose respiratory risks to your house’s residents. Allowing damp, stale air out and fresh air in through ridge vents prevents condensation from forming on interior roofing materials.

Extended Roof Lifespan

Ridge vents provide the best roof insulation by leading to more ventilation through your home’s upper tiers. This ventilation reduces strain on your roof by keeping the attic at nearly the same temperature as the outside air. In cooler months, this means a decreased risk of ice and snow buildup—a hazard that can damage roofing and force you to face the cost of installing a new roof.

Here are the types of ridge vents you’ll find on the market:

Shingle-Over Ridge Vents

This vent type is installed at a roof’s peak and is covered with a special layer of ridge cap shingles. Some models come equipped with a baffle, which is an exterior channel that allows for additional airflow and prevents windblown rain from getting inside the vent. Ridge vents with a baffle cost more, but they help prevent wind, water, and insects from coming into the vent. 

Exposed Ridge Vents

An exposed ridge vent is made of finished aluminum and isn’t covered by any other roofing material. It’s more visible than a shingle-over vent, but it’s easier to install, and the exposed metal can add visual interest to the roof.

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:

1. Remove enough shingle caps and shingles on the roof’s peak to expose at least three inches of roof decking.
2. Cut an opening for ventilation in the decking along the peak.
3. Reattach existing types of roof shingles to cover the exposed deck, adding new high-quality roofing shingles as necessary.
4. Place the ridge vent over the ventilation opening and nail it down on each side as instructed by the manufacturer.
5. Seal edges with caulk as recommended by the manufacturer.
6. Add any connectors or end caps that came with the ridge vent.
7. 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:

• Vent material will expand and contract slightly with temperature changes. Leave a gap of about 1/8 inch between sections to prevent buckling.
• 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.
• Don’t overdrive the nails, which can cause buckling.
• Use the right nails. These should be included with the ridge vent and are different from the nails used for regular shingles.
• When installing ridge cap shingles, use two nails on either side of the shingle to protect against strong winds.

Maintenance Tips for Homeowners

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.

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

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

Gable vents are a different type of ventilation system. They are 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.

Power Vents

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. To keep the roofing system cool in the winter, 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 conditions.