How To Properly Vent An Attic – What You Need To Know

Since hot air rises, your attic often becomes one of the warmest spots in your home. Also, it’s filled with insulation that could have off-gassing that requires ventilation. Whatever the case is in your home, knowing how to properly vent an attic is crucial to prevent the accumulation of pollutants and harmful gasses.

In this post, I will share some tips that you can use to keep your attic ventilated. It’s way different than other rooms in your home because, in an attic, you have a smaller room to work on. Also, it is elevated, and hot air can be challenging to get rid of. 

How to know if your attic needs ventilation

how to properly vent an attic

Proper attic ventilation reduces heat and pollutant buildup. This makes your attic suitable for living or storage of your belongings. But when does it need ventilation?

Basically, you need to ventilate your attic regularly. Maintaining healthy humidity levels will keep pests and rot at bay. Still, there are some signs that you can check to confirm if there’s an urgent need for ventilation. Here are some of it:

  • Frost. If there’s frost or dampness in your attic, it’s a sign that you need to ventilate the room. During the winter season, escaping warm air from your home can lead to condensation. It often occurs in the roof sheathing or rafters. You can use a flashlight to inspect these parts.
  • Extremely hot ceiling. If you can’t stand touching your attic’s ceiling for more than three seconds, it’s a sign that the room is overheating. This situation will increase your energy bill as your AC units compensate for the cooling process.
  • Stuffy odor. A stuffy attic simply means that the air is stagnant and that pollutants have already accumulated inside. This is very important to get rid of, or it will soon spread all over your home. That spells allergic reactions and respiratory irritations.

The goal here is to prevent these situations from occurring. This is possible by ventilating your attic regularly and placing vents that will keep the air moving.


What will happen if you don’t vent your attic?

Many homeowners are guilty of neglecting their attics for too long. Aside from the clutter and dirt, the following will occur if you don’t ventilation your attic:

  • Formation of molds and mildew. Your attic is probably the most suitable place for molds and mildew to thrive. It’s often dark, and the accumulated moisture due to lack of ventilation will fuel the proliferation of the mold spores. Before you know it, there’s a brewing mold infestation in your home.
  • Premature roof damage. Another result of poor attic ventilation is premature damage to your roof. This is due to trapped moisture that will rot the roof material. Instead of lasting for decades, you may need a premature roof replacement, which can cost a fortune.
  • Higher energy bills. Trapped heat will jack up your energy bills as your HVAC system will use more power to cool your scorching hot attic. This could have been prevented if you vent it properly throughout the year.
  • Ice dams. A poorly ventilated attic has warm air. During winter, this warm air will cause snow that falls into the roof to melt. The water will then drip into the roof’s bottom then refreezes. These ice dams can damage your gutters and pose a risk to someone standing underneath.

All of these are enough reasons to observe proper ventilation in your attic. If you’re wondering how to do it, the tips below would be a big help.


How to properly vent an attic

Venting an attic requires time, effort, and a few materials. The following are some of the most effective ways to keep your attic’s indoor air properly ventilated:

🏠Open the attic windows

The easiest way to cool down your attic during a hot summer day is by swinging its windows open. This will allow warm air to escape and fresh air to replace it.

However, I have some caveats about this method.

First, you should avoid opening the windows if your place experiences intense pollen levels. In this case, opening the windows would be counterproductive as the pollutants in your attic would increase.

Also, this isn’t a smart move during winter as it will allow freezing air to enter. When that happens, your heaters would have to work harder to regain the warmth of your home.

Lastly, some attics have no windows, so this may not be applicable to some homes.


🏠Use vents

how to properly vent an attic

The most effective way of ventilating your attic is installing vents. There are multiple types you can choose from, including the following:

  • Intake vents
  • Ridge vents
  • Box vents
  • Off-ridge vents
  • Cupola vents
  • Roof turbines

Intake vents

Intake vents come in four types: soffit, over-fascia, gable, and drip edge vents. As how it’s called, these vents bring fresh air into your home. It’s possible by placing the vents lower into the roofline, unlike exhaust vents that extract hot air.

Of the four types, soffit vents are the most popular since it’s also easier to install. It’s also the most effective in terms of air intake when paired with a ridge vent.

This is followed by gable vents, which are triangular-shaped and placed on the side of the attic roof.

Meanwhile, an over-fascia type is installed right under your gutter. It’s suitable for roofs with no eaves where soffit types can be fitted. However, the efficacy of over-fascia intake vents is in question because it’s too narrow.

Lastly, drip edge vents are basically drip edges with perforated parts to allow airflow. If you don’t have enough eaves for a soffit, drip edge vents are good alternatives.

Overall, intake vents are yin, and exhaust vents are yang. It comes hand in hand for proper ventilation of your attic.

Ridge vents

Ridge vents, on the other hand, are the most common type of exhaust vents among houses. It’s installed at the peak of the roof and stretches throughout the roofline. It’s often included in most roofing installation packages.

This vent type is so popular because it’s also very effective. It’s placed right on the best spot on your roof for ventilation. And due to its large coverage, your attic will be ventilated properly.

Moreover, ridge vents allow warm air to escape. It works even better with a soffit intake vent since both utilize the natural flow of hot and cool air.

The good thing about modern ridge vents is that they are often very strong that a person can stand on them without the material cracking. It also lasts longer than other vent types, which will help you save money in the long run.

Box vents

Also known as Louver vents, box vents are available in various sizes, but the most common is 18 x 18 inches.

These box vents are installed across the roofline. You can use multiple box vents for optimal ventilation of your attic. However, since they are small, they don’t ventilate as much as ridge vents unless you install many of them.

Still, box vents are the usual option for homes with complicated rooflines that are composed of multiple sections. It’s also a good choice for roofs where a ridge vent isn’t possible to install.

Off-ridge vents

Similar to box vents, off-ridge vents are placed across the roofline. It’s often made of metal and installed on three shingle slabs.

Overall, this vent type isn’t very popular and not as effective as other vents. However, if your roofline is small or narrow, this might be the best solution. It also comes in handy for roofs with small eaves.

Nevertheless, off-ridge vents can be used in conjunction with other vent types. This is to improve the ventilation of your attic if it’s prone to moisture buildup.

Cupola vents

Cupola vents require more expertise to install since it has a larger protruding structure. It’s similar to a chimney, except that it has a red metal roof and louvers/slats on the sides.

Like off-ridge vents, cupola vents aren’t that popular because of the complexity, cost, and upkeep. It’s also not suitable for all areas, especially those that receive a lot of snow during winter. But if you don’t mind paying for premium ventilation, you can always try a cupola for a change.

Roof turbines

Roof turbines are very popular modes of ventilation for attics. Some call it ‘whirlybird’ as it spins on top of the roof. It’s made of metal and requires a wind speed of at least 5 miles per hour to do its magic.

Moreover, roof turbines are more affordable than cupolas and more popular as well. It acts as a large exhaust on your roof, although installation can be pretty challenging.

Another good thing about this vent type is its eco-friendly design. It doesn’t require electricity and the material lasts pretty long. But just like cupolas, they are not suitable for every home.


🏠Run an air purifier/dehumidifier 

Aside from installing vents, another great way to ventilate your attic is by using an air purifier and dehumidifier. As the air purifier removes irritants and pollutants, the dehumidifier will suck out excess moisture. This is very effective in preventing condensation and damage to your roof.

However, make sure that you’re using an air purifier or dehumidifier suitable for the floor size of your attic. This is to guarantee that the devices are performing well in cleaning the air and ventilating the room.

When using a dehumidifier, draining is very crucial. If you can’t use a continuous drain option, make sure that the unit you’re going to buy has a large water tank.

Meanwhile, you should select an air purifier with activated carbon to neutralize malodors and harmful gasses.


Frequently Asked Questions

Q: How much does it cost to add attic vents?

A: Attic vent installation cost varies widely, depending on your location and the type of vent you’re planning to install. Usually, it will range from $300 to $700, which is inclusive of labor and materials. This cost can be higher and lower based on the size of the roof and the challenges that entail the installation.

Q: Should I install gable vents if I already have soffit vents?

A: Soffit and gable vents are an excellent pair with soffit vents. It allows ideal air intake and extraction. Gable vents function both as an intake vent and an exhaust, which will complement the effect of soffits. Just keep in mind that this additional installation will also cost more.

Q: Do attic vents help cool the entire house?

A: Attic vents can help reduce the indoor temperature of your home. It will also prevent trapped warm air from making it harder for your air conditioner to maintain the desired temperature. If installed well, your attic vents will bring a myriad of benefits to the entire house. Just make sure that you also maintain it all year long.

Q: Can you over-vent an attic?

A: It’s not possible to have too much intake air in your attic, but you can have too much exhaust. This is because the excessed intake air will be converted into exhaust later on. As long as your vents are functioning properly, over-venting shouldn’t be a problem. You should also ask the help of a professional roofer to ensure that there won’t be excessive exhaust ventilation.

Q: Can you install too many soffit vents?

A: There’s no such thing as ‘too many soffit vents’. As an intake vent, you can install as many soffit vents that you like. Still, you should observe the minimum requirements, which is 4 x 16 inches. You should also check with your local building codes to be sure of the proper measurement.


Final words

Knowing how to properly vent an attic will save you from expensive roof damage later on. It will help keep your home cooler while preventing noxious gasses from accumulating in your attic. Also, ventilation is a good way to disperse airborne irritants. When paired with an air purifier or dehumidifier, your attic will have excellent air quality.

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