The installation of roof vents is a crucial part of the roofing system and design. Proper ventilation in your roof helps control any excess moisture and heat that cause condensation and early aging of your other roofing materials. The best roof ventilation systems don’t just extend the lifespan of your roof. They help lower your home’s energy bills and help make your house an overall healthier place to live due to the boost in air quality that proper roof ventilation offers.
With any product, there are different types of roof vents that are more effective than others. However, each vent type has the task of either removing old, stale air from your attic (exhaust vents) or bringing fresh air into your home (intake vents). To ensure you have proper roof ventilation, you must have both types of these vents installed.
Why Proper Roof Ventilation is Important
Heat and moisture buildup in an attic can cause quite a few problems. Many of these problems are predictable. Different issues can occur in conditions of extreme heat or extreme cold.
When it’s hot outside, and the sun is beating down on your roof, the temperature in the attic can increase. Exposure to excessive heat can cause warping to the roof’s sheathing and distort and prematurely age the shingles. Another side effect is heat radiating down into the living areas if the attic floor is not adequately insulated.
If you live in an area where the temperature drops below freezing during the wintertime, warm air escaping into the attic from the heated living area below rises to the underside of the roof decking. As the roof decking warms, the bottom layer of any accumulated snow or ice begins to melt, causing water to trickle down the roof. Once this runoff water reaches the cold outer edge, it will refreeze into ice. If this continuously happens, it will form what is known as an ice dam. Once an ice dam forms along the eaves of your roofing system, it blocks the escape of further runoff water. Once the water has nowhere to go, it can back up under the shingles, causing potential wood rot and roof leaks.
The Two Roof Ventilation Types
Since hot air rises, roof exhaust vents are generally installed towards the top of your roofline. This type of vent is designed to take all of the hot, stale air out of your attic, and in turn, the condensation that comes with hot air. If the hot air in your attic is allowed to remain motionless, it will eventually lead to bad-smelling mildew growth and eventually mold growth.
Types of Exhaust Ventilation
Ridge vent is the most common exhaust ventilation. A ridge vent sits at the peak of your roof and runs across the entire span of your roofline. When installing, an air slot is cut into the roof first, and then that the ridge vent covers the air slot. Ridge cap shingles are then installed over the ridge vent to protect it.
Off Ridge Vents
The most popular brands of off ridge vents are approximately 4 feet in length and made of galvanized steel. They are installed by cutting a hole the size of the vent in the roof approximately one foot below the ridgeline.
Box Vents (also known as Louver Vents)
Box Vents are installed similarly to Off Ridge Vents by cutting a hole the size of the box vent into the roof. There are a wide variety of sizes available so that you can choose the size best suited for your space. The most common sized Box Vent on the market today is 18 inches by 18 inches.
Hard-Wired Powered Attic Vents
Hard-Wired Powered Attic Vents are electric propelled fans that help pull stale, hot air out of the attic space. They work similarly to a box fan placed in an open window on a hot day. While these vents effectively pull the hot, stale air out of your attic, they do come with higher electricity bills.
Solar Powered Attic Vents
Solar Powered Attic Vents work exactly like a Hard-Wired Powered Attic Vent but remove almost 100% of the electricity costs associated with Hard-Wired Powered Attic vents.
Roof Turbines (also known as Whirlybird Ventilation)
Roof turbine vents were first used in the early 1900s and consist of aluminum blades inside an aluminum covering known as a cowl. Turbine vents rotate using the wind to pull air up from inside the attic and out of the home. Roof turbines need winds of at least 5 to 6 miles per hour to activate and spin the interior blades.
Cupola Vents are among the least common types of roof vents due to their cost and complexity of installation. Cupola Vents were originally used in barns. The vents allow air into a barn loft and help dry hay and other crops within the barn. We see these types of vents installed on homes to allow extra light into the area underneath the vent.
The exhaust vents that help hot air leave your attic space are important for your home’s health, but hot air can be stubborn and sometimes needs to be pushed out, and that is where intake vents come in. The intake vents allow cooler air to come into your attic space and are installed onto your roof lower than the exhaust vents. Since the cooler air enters the attic underneath the hot air (and because hot air rises), the intake ventilation will help push the hot air out of the attic space.
Types of Intake Ventilation
Soffit Vents are the most common form of intake ventilation. These vent types are unquestionably the most effective intake vent for the cost. Soffit Vents are installed directly on your eaves, which is the area directly under your roofline. You can choose to install continuous soffit vents that often wrap around the entire eave of the home or individual soffit vents, generally spaced six feet apart on the eaves.
Gable Vents are generally used with a gable style roof as a vent can be placed on either side of the home. The premise of these vents is that air flows in on one side of your attic and out through the other side. These vents come in all shapes and sizes, but the most common choice is a triangular shape that sits directly below the peak of your roof.
Over Fascia Vents
Over Fascia Vents are a newer form of roof ventilation designed primarily for roofs that do not have enough eave space to install Soffit Vents. A Fascia Vent is placed at the top of the fascia board and gutter and directly underneath the starter row of shingles.
Drip Edge Vents
While not every roof has a drip edge installed, a drip edge is designed to go directly under the first row of shingles to help drain water off your roof and into the gutters. A Drip Edge Vent incorporates a standard drip edge with small holes either drilled into the drip edge installed or attached as an add-on.
Which Roof Ventilation Option is Best for your Home
The best way to go about figuring out the best roof ventilation option for your home is to have a local roofing contractor come out and perform an inspection of your home. The inspector will provide you with their recommendations as to which roof ventilation type will be best for your home. How many vents are needed to provide the most benefit to your home depends on what kind of ventilation they recommend. If you live in the Charlotte, NC market or surrounding areas and want to ensure your roof ventilation system is working properly, reach out to Signature Exteriors today. Give us a call at (704) 729-4898, or send us an email, and one of our team members will promptly be in touch.