Our attics collect a lot of heat, especially if you’re living in a hot and humid climate – which is where a gable vent comes into play.
Excessive heat and moisture in an attic can do some serious damage to your home, from causing the early degradation of your roof to the growth of harmful mildew and mold.
Those issues can lead to thousands of dollars in repairs, which is why proper ventilation is crucial.
One of the most common attic ventilation systems is a gable vent.
These vents are installed to the side of attic walls and, in theory, give hot air a place to escape.
But if you’re thinking about installing gable vents or modifying your current ones, there’s some important information you need to consider.
So, let’s closely answer the question of what is a gable vent and dive into the top things you need to know about them!
1. What is a Gable Vent?
Gable vents are a type of exhaust vent that is installed on the walls of attics.
Their purpose is to allow proper airflow when an excessive amount of heat occurs.
Throughout the year, attics can become dangerously hot and cause mildew and mold to grow and damage the roof.
There should be at least two gable vents located on either side of the attic to allow a breeze to move through the room.
Gable vents can be paired with other ventilation systems, but you need to be careful–two ventilation systems improperly placed can actually do more harm than good (see sections below for more information).
This type of ventilation system is standard for most homes; they’re also cheap, making them a great option for anyone looking for a quick and easy solution for their attic.
Gable vents come in all shapes and sizes, so let’s talk about which ones are best.
2. Which Type of Gable Vent is Best?
You can find gable vents in nearly every kind of material.
But which one should you choose?
Let’s first talk about materials to avoid.
Wood should be avoided.
Wooden gable vents are more commonly seen in older houses; we have better options today.
Wood easily rots and gets warped by extreme temperatures.
Depending on where you live, a wooden gable vent might only last a few years.
Plastic and vinyl vents, like wood, have a short lifespan.
The hot air from the attic and the heat from the sun causes them to dry, crack, and warp.
Critters have also been known to chew through plastic and vinyl vents.
Galvanized metal is a strong, durable option.
The problem is that it easily rusts.
You could apply a coat of anti-rust paint, but if you forget to reapply it, one season of rain will bring on the rust.
Ready for the best material?
The best material for gable vents is aluminum.
Aluminum vents are durable, unaffected by heat (no warping), and too hard for animals to chew through; they will also not rust.
If you install aluminum vents, they should last for 50 or more years!
3. Do Roofers Install Gable Vents?
Roofers will install gable vents; it’s recommended you have a professional take care of the task to ensure they’re properly installed.
If the vents aren’t put in correctly, it could be an invitation for critters and insects to enter your attic–no one wants that to happen.
While roofers install the vents, they should also investigate any other ventilation systems that were already in place.
Sometimes multiple systems can work against each other, which is another reason it’s important to have a professional handle the task.
Gable vents cost around $175, and you can expect to pay another $175 for installation fees.
That’s a total price of about $700 if you install two of them, but aluminum vents can last more than 50 years, so it’s money well spent.
As always, choose a roofing company that’s reputable.
Just because some roofer knocked on your door and offered his services doesn’t mean you should do business with him–do your research.
4. Should Gable Vents Be Closed in the Winter?
Keeping your gable vents open during the summer is a no-brainer.
But what about the winter?
Gable vents should be left open during the winter–no questions asked.
Although closing them off during the colder months might seem logical, it would create the very problems the vents are there to prevent.
Closing your vents in the winter would stop the airflow in the attic.
Additionally, homeowners will likely be running their heaters during the colder months, and–as we all know–hot air rises. Without vents, hot air would have nowhere to escape.
There may be some instances, such as heavy wind and rainfall, when closing your vents would be a good idea.
But, as a rule of thumb, don’t close your vents in the winter–it could take years off your roof’s lifespan.
5. Does Water Get into Gable Vents?
It is possible for water to get through gable vents.
Water can be a real issue, causing damage to the attic flooring and introducing moisture to the room.
So how can you stop this from happening?
Well, some gable vents are already designed to keep water out.
These vents will have two sets of slats, one that’s pointed down and the other that’s pointed up. This design helps prevent rainwater from blowing in.
Another option is to install deflectors on the top of the vents if water is draining down from above.
Lastly, no matter what type of gable vent you have, it needs to be properly sealed.
Gaps along the perimeter of the vent can lead to a lot of water sneaking through.
You can seal a gable vent with caulk or sheet metal.
If you do decide to close your gable vents during a heavy storm, immediately open them when the storm passes.
Keeping them closed off means the attic is not being ventilated, increasing the chances of issues occurring.
6. Can Animals Get Through Gable Vents?
Unfortunately, gable vents can be an easy entryway for animals.
Not all gable vents are equal.
Some are made with flimsy materials that can be bent or chewed through.
Common animals that are able to enter an attic through gable vents are mice, squirrels, bats, and raccoons.
Yes, even a big raccoon can manipulate some gable vents to break into your home–that’s an issue.
Well, don’t let the idea of critters crawling through your vents scare you because there are some simple steps you can take to avoid it.
Install strong, durable vents.
Add steel mesh.
Install a vent cage.
Relocate the vent.
If you’re having a pest problem with your gable vents, the first step would be to install strong, durable vents.
The best material to use would be heavy-grade aluminum, which would be too strong for raccoons to open.
You could also add a lining of steel mesh to prevent small critters like mice, bats, and squirrels from getting through. Just make sure to use something they won’t be able to chew through, like hardware cloth.
Another option is to install a vent cage (also referred to as a vent guard). These are metal cages that go over gable vents.
The cages work well to keep out animals, but they’re not aesthetically pleasing.
If you’re having continuous issues with animals entering a certain gable vent, consider moving it somewhere that’s more difficult for animals to reach.
7. What Happens If an Attic is not Vented?
Attics can seem like a detached part of the house.
But they are very much attached, and not installing proper ventilation can cause big issues.
Let’s take a closer look at what can happen to an attic that’s not vented.
Mildew and Mold
Mildew and mold are common problems in attics without proper ventilation.
During the winter, warm air from the house rises through the attic and comes into contact with the cold attic roof, creating condensation.
That condensation then drips onto the floor or along the ceiling and causes mildew and mold growth.
Excessive Heat
Attics can easily become hot without ventilation.
If heat isn’t able to escape through vents, extremely hot temperatures can damage roofing materials.
Ice Dams
A poorly ventilated attic will be warmer than the outside temperature during the winter.
If it snows, the warm ceiling of the attic will heat the roof and cause the snow to melt.
That melted snow will then create a ridge of ice at the edge of the roof, preventing melting snow from properly draining.
Backed-up water can result in mold and mildew and damage roofing materials.
Early Roof Degradation
Over time, an attic that’s not vented will begin to degrade from excess moisture and heat.
Nails and flashing will rust, leaks will occur, mold and mildew will accumulate, and the overall integrity of the roof and attic floor (the home’s ceiling) can be threatened.
8. Where Do You Put a Gable Vent?
When answering the question of what is a gable vent, we need to talk about placement.
Gable vents should be placed on both sides of the peaks of a gabled roof.
Placing them across from each other creates airflow and allows the breeze to easily enter and escape.
In an ideal scenario, gable vents are aligned with the direction of the region’s primary winds.
If the prevailing winds are perpendicular to the home (and gable vents), the ventilation system will not work as well.
It’s also important to know that gable vents do not work well with ridge vents.
Using the two ventilation systems can disrupt the airflow and result in improper ventilation–that’s not what we want.
Sometimes, if there’s enough distance, two ventilation systems can work together.
So, if your home already has a ventilation system, talk with a professional roofer to find out if installing gable vents would be a good idea.
9. Is an Attic Fan Necessary with Gable Vents?
If you believe your gable vents aren’t providing enough ventilation, attic fans can be the answer to your problems.
Attic fans will help keep the space cool, lower moisture levels, and increase airflow.
But here’s the deal, attic fans are becoming much less popular.
Most newer houses are actually built without them.
Let’s take a look at why houses aren’t typically built with attic fans anymore and the best type of fans to use if you choose to install them.
10. Why Don’t They Put Attic Fans in Houses Anymore?
Traditional attic fans, when used alone, don’t always provide enough cooling or ventilation to be effective.
The original thought behind attic fans was that they would reduce how often a homeowner would have to run air conditioning.
Well, it turns out that running traditional attic fans for long periods of time can actually be more expensive than relying on air-conditioning units.
But thanks to new technology, there’s a viable solution.
Homeowners can now install solar attic fans–fans that run off solar energy.
These fans are capable of cooling an attic by about 20 degrees and cost zero dollars to run.
You can find solar attic fans for about $300 to $500.
Just make sure to consult with a professional roofer to ensure the fan is installed in the best location.
11. Can I Have Too Many Gable Vents?
Too many gable vents can negatively impact the ventilation of an attic.
Most houses will only need two gable vents–one on each side of a gabled roof.
If your home has multiple gabled roofs, it could be beneficial to have a gable vent at each end.
When you notice signs that your attic needs better airflow (but you already have gable vents), you should install other types of ventilation systems, such as soffit vents.
But how do you know if your attic’s ventilation systems need to be improved?
12. How Do You Tell if an Attic is Properly Ventilated?
Figuring out whether or not your attic’s ventilation system needs to be improved is fairly straightforward.
The first thing you’ll want to do is look for symptoms of poor ventilation.
Check the area for mildew and mold, look at the quality of the vents, and search the edge of the roof for ice dams.
On hot days, feel the ceiling. Excessive heat is a good sign of poor ventilation.
If you want to get a clear idea of how well your attic is ventilating air, you can perform the smoke test.
To perform the smoke test, bring a fog machine up into the attic.
Turn the machine on and see how well the attic pushes out the fog.
Windy days will blow the fog out quicker than non-windy days, but regardless, the fog should not get stuck in the attic.
You could also do this by lighting incense in the attic; however, you need to be very cautious as attics contain highly flammable materials.
Final Thoughts
So, do you feel like you could confidently answer the question: What is a gable vent?
Ensuring your attic is properly ventilated is crucial if you want to avoid big, expensive problems in the future.
Heck, if you put it off long enough, you might have to get a whole new roof–no thanks.
Gable vents are a great and inexpensive way to improve the airflow in your attic.
Unless you’re experienced in installing ventilation systems, speak with a roofing company to ensure the job is done right.
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Disclaimer: we are not lawyers, accountants or financial advisors and the information in this article is for informational purposes only. This article is based on our own research and experience and we do our best to keep it accurate and up-to-date, but it may contain errors. Please be sure to consult a legal or financial professional before making any investment decisions.
Prior to starting Gokce Capital, Erika received a Bachelor of Architecture from the University of Southern California and a graduate degree in Urban Policy from Columbia University. She worked as both an architectural designer and engineer in New York before joining the New York City Department of Housing Preservation and Development.
Erika currently lives in the New York Metropolitan area with her spouse, daughter and cat. She is originally from Chicago and still considers herself a midwesterner at heart.
Erika also loves to read, write and travel (fun fact, she has visited all 50 states and more than 30 countries!). Her new book, Land Investing Mistakes: 11 True Stories You Need To Know Before Buying Land, is now available on Amazon.