Roof Ventilation: How Many Vents You Need And Different Types Explained

Ventilation for a house is all about letting the old, stale air out and new, fresh air in. The best ventilations will not just extend the life of your roof, but also help to bring down the energy costs, make your indoor atmosphere a lot more conducive to living, and best of all, help to extend the life of your roof by a great extent. For any homeowner, their home is an oasis of rest and comfort.  

In this article, we will see more into why you should have proper ventilation in place for your home, and how it helps to safeguard your home from extremes in temperature, and the ways it helps to protect the integrity of your roofing system. 

Roof Ventilation

What Is Roof Ventilation?

Now, according to the National Roofing Contractors Association (NRCA), and the building codes of the municipality in which your house is located, not to mention any roofing contractor you hire, the amount of ventilation space for your attic floor space is 1/150. It means you need to install 1 square foot of vent area for every 150 square feet of attic floor space. 

Roofing ventilation or attic ventilation is a system that allows the air to circulate and flow through the attic space, to keep the air cool during the summer and dry during the winter

Before you install ventilation for your roof, you will need to consider the following factors:

  • Building code
  • The climatic conditions of your place
  • The design of your roof

What Is The Purpose Of Roof Ventilation?

Roof ventilation is essential for every home no matter the climate. During the summer, the roof vents will help to keep your attic cool. So, how about during the winter? Roof vents during the colder months of the year will help to keep the attic nice and dry. It is important to keep the air in your home space dry, otherwise, mold and mildew formation is inevitable. 

During the summer when the temperature outside soars, you naturally take a retreat inside your home whenever it is possible. During the hot months of the year, a good ventilation system in your attic will allow all that hot air to escape the attic space. What effect will this have on your home? Well, for one, the overall temperature of your house will be reduced. Moreover, without a ventilation system in place, your air conditioner will have to work extra hard to maintain a comfortable indoor atmosphere. Roof vents will reduce the load on your air conditioners.

During the winter months, when it snows an awful lot, the attic ventilation is just as important. When it gets super cold outside, warm air that is trapped in your attic space will lead to the snow melting and refreezing as ice. When there is no vent for that warm air to escape, the result is ice dams on your roof. 

The heat from the sun and your roof will end up melting all the snow and ice; when a lot of water gets clogged up over your roof, it refreezes to create puddles along the surface of your roof. Now, these ice dams lead to mold and mildew growth and can cause enormous damage to your roof. It could affect your health too! A proper ventilation system will clear the moisture in your living space and allow it to escape through the attic.

  • Hot air, when trapped in your home, will make it virtually impossible to keep the indoor temperature of your room cool and comfortable.
  • Hot air trapped inside your house during the winter will result in mold, mildew and ice dams formation. 

So, you MUST have a good roof ventilation system in place to maintain a conducive indoor atmosphere all year round and protect your roof, and consequently home from damages that could lead up to costly repairs. Not what you want, we bet!

Now that you know why it is so important to have proper roof ventilation in place, let’s get right into two roof ventilation types for your home.

The Two Styles Of Roof Ventilation

So, the working of a roof vent is straightforward. They pave the way for continuous airflow in your attic space, remove hot air as well as moisture from the attic and your roof, and reduce the impact of extreme temperatures both outside your home as well as inside. 

1. Exhaust vents: Exhaust vents have the work of getting rid of stale air from your attic space. Hot, humid and stale air are the consequence of stagnant hot air that rises in your attic but has no room to escape. Stagnant hot air can lead to mildew and mold. Have you ever wondered why your attic smells so musty at times? The reason is most probably lack of ventilation. Exhaust vents take their place at the top of your roofline.

2. Intake vents:  Intake vents do the job of bringing in fresh, cool air into your home. Placed below the exhaust vents, cool air enters right below the hot air and ends up pushing all that trapped hot air out of the attic space.

The Two Types Of Roof Vents

Ventilation is all about creating airflow. Airflow can be achieved by natural means while some require a power source or electricity. 

Natural Ventilation: Air flows through the attic due to the stack and wind effect. Feeling lost? Allow us to elaborate. If you have read the guide till now, you will know that hot air will arise within a room. This will create high pressure at high points in the attic. If enough room is given for the hot air or high-pressure air to clear out, it will be replaced by cool (low-pressure) air. So, obviously hot air will move out and in turn, cool air will come in only when there is the option for an inlet. The air that escapes is the exhaust, while the cool air that comes in is called the intake.

What about the wind effect though? When a heavy gust of wind blows against your house, and your roof, it will give rise to exhaust as well as intake. This is the wind effect. Now both these are necessary for an attic that is properly ventilated. Remember, hot trapped air out, cool; fresh air is happening constantly!

You can very well make use of the airflow that can be created as a result of the thermal difference to keep your indoor space nice and comfortable. Natural ventilation can be fixed in doors, windows, and other gaps.

Mechanical Ventilation: While natural ventilation does not require any additional help, mechanical vents make use of a power source for continuous airflow. Let’s say your property is located at a place where it’s not very windy, or there are too many buildings surrounding your house, or your roof design and construction is such that there is not much airflow into your home; then the use of mechanical vents become necessary.

Now, you should know that there are different vents. The right roof vents for your home depends entirely on the climatic conditions of your locality and your roof (and home) design. Let’s look at some of the roof vents out there. You can choose the roof ventilation system(s) for your home based on your home’s specific needs.

Different Types Of Roof Ventilation

Intake and Exhaust Vents are installed at different parts of your roofing system. 

Intake Vents

These allow the cool, fresh air inside. You can make use of intake vents to circulate cool air within your home and prevent it from overheating. When fresh air rushes in, hot, musty air rushes out in a hurry! Used in conjunction with exhaust vents, intake vents not just help in strengthening the air circulation and minimize the attic heat to keep your indoor space cool and comfortable, but they also help to keep your energy costs at bay and extend the lifespan of your roof by shielding it from ice dams.

These are the common intake vents. To achieve an optimal balance of low and high-pressure areas, you can make use of the following intake vents.

Soffit Vents: Soffit or eave vents is one the most common intake vents. Soffit is harder to spot on the outside because it is the material under the eaves of your roof. Soffit vents are placed in two strategic spots. One will run the entire length of the soffit while the other will be placed between the joists. They can also be placed under the drip edge by the gutters or at the roof’s edges beneath the shingles.

Gable Vents: These are somewhat outdated, and generally, they are used with gable roofs. They function as both an intake as well as exhaust. Now while gables vents help in letting air in or out, they are not of much help in circulating the air evenly throughout your attic. They are installed at the end of your attic, or the gable end of your building. Gable vents or louvered vents not just help air to be drawn out of your attic space; they are also effective in preventing snow, rain, and moisture from being blown back in.

Now to exhaust vents! 

Exhaust Vents:

There are more varieties of exhaust than intake vents, ridge vents being the most common of the lot. Exhaust vents work by allowing the (trapped) air to escape. Say goodbye to stagnant, trapped air with these exhaust vents!

Ridge Vents:

One of the most popular venting options, roof vents are an indispensable part of any house you are looking to purchase. These vents are installed at the peak of the roof slope (and under the shingles, they do more than just venting certain specific spots of your roofing system and protect your home from rain and snow; they allow for an even distribution of air and keep the air in your home space under constant circulation. Since it sits atop the peak of the roof, the installation is easy. But since they run the entire length of the roofline, they are expensive too! 

The position also means they are located in the best possible place to let hot air out the attic space. But trust us, your dream home and the wonderful roof design you spent hours selecting deserves a ridge roof ventilation! They don’t just create hot and cold spots in your room, they distribute hot and cold air evenly across your roof. This means only one thing – the integrity of your room will remain in top-notch condition for years on end!

Another reason ridge vents are so popular is that they blend in with the natural appearance of the roof and are not obvious to the naked eye. Now, that’s protection and ventilation to give the ultimate indoor conducive atmosphere without disrupting the appearance of the roof.

A pro tip, when you use this type of vent with the previous option listed (soffit vent), the combination of the two will end up giving the best ventilation you can imagine! If your roofing contractor doesn’t include a ridge vent in the roofing project, we highly recommend you have a nice, long chat with them and get them to install one for your home.

Wind Turbines:

Wind turbines (or whirlybirds) are yet another option that works without any power source. You must have come across plenty of those in older homes. There is a catch, however; your home should be located in a very windy place. So, how do they work? They catch the wind and airflow in the turbines as the wind turbine spins. Hot and humid air will then be let out by the vanes, and in its place, the cool wind will come gushing in making your attic and consequently, your indoor space, cool and refreshing.

Constant wind circulation is a must for wind turbines. They may look cool, but they are not all that effective when there is little or no breeze. And we’ll admit something, they are not the best vents even on those strong windy days! But that doesn’t mean it’s all doom and gloom. There are some cons to having whirlybirds as a roof ventilation option. They are eco-friendly, they are very easy to maintain, and you hardly hear them at all even on those days when the wind blows in a fury!

Box Vents:

Box vents or Louver vents are installed as a whole bunch for additional ventilation. Just one or two won’t just do the trick – you need to install a host of them for the best ventilation solution for your roof. 

Box vents are named so because they take the shape of, well, boxes! These are just as popular as ridge vents with good reason. They are a bit small but don’t let their size fool you. They are super versatile, even more versatile than ridge vents, in fact!

You may have seen rooftops with several box vents. They work by allowing hot air to rise and moisture to escape effectively, as they are installed close to the roof ridge. It is at the roof ridge that most of the hot air will automatically escape.

For one, they don’t need to run across the entire roof horizon, as is the case of ridge vents. You can get them installed snugly in small areas on your roof that absolutely need ventilation but don’t have enough space to accommodate a ridge vent.

A box vent is ideal for complex roof lines with lots of intrinsic details, holes and little nooks inside which you can install the box vent system. However, if you have a large and simple roofline, we recommend the use of ridge vents. Like with ridge vents, you should ideally use them along with a soffit vent for optimal ventilation performance. 

Power Attic Ventilators:

Power attic vents are a type of mechanical roof ventilation that runs on power, obviously! If your home is not located in a very windy area or your roof design is such that exposure to the wind is minimum, power attic ventilators are a great option! This electric roof vent will run continually on the power source to keep your home at an optimal temperature and to provide sufficient ventilation for your roof. You can avoid extremes of temperatures with this type of vent.

Power attic ventilators are electric-propelled fans that help in evacuating stale air out of the attic space. There is one drawback, however; a higher electric charge on your home energy bill! When used for years, the operational costs just keep adding up, and we leave it to you to decide if they are worth investing in.

Signs of Poor Ventilation

Now, there are various signs, most of them apparent, which indicate that your house can do with a ventilating system. 

1. When you notice icicles and ice dams on your roof, it means there is something awfully wrong with your roof ventilation system.

2. One of the reasons for the musty attic smell is the improper ventilation system in your home.

3. Noticed varying temperature spots in your house as you move from one room to the other? You may even have felt chilly at the lower flight of stairs and warmer as you climb up. This is a pretty good indicator of ineffective roof ventilation. If nothing is done about it, hot air cannot escape and will be trapped in the upper rooms, making them warmer (and more uncomfortable to be in!).

4. Roof leaks, mold and mildew formation is a sign of flaws in your ventilation. It could pose serious health issues not just for your roof and building but your health as well. After a heavy shower or storm, water will be collected atop the roof. If the excess water is not drained after such events, or if your roof is damaged because of a storm or rain, the undrained water will accumulate and eventually lead to mold and mildew formation. This could lead to health issues like cough and irritation to the throat, eyes, and skin.

5. This is a less obvious one, but the performance of your air-conditioner could indicate how poorly or otherwise your ventilation is performing. Improper ventilation could cause hot air to be trapped inside, and your air cooler will work on overload to keep your indoors cool. The increased pressure on the air conditioner may cause it to be repaired often. So, if you want your HVAC (Heating, Ventilation, and Air Conditioning) system to work in prime condition, ensure that you have a proper ventilation system in place.

Benefits Of Proper Ventilation

If you are a homeowner, have no second thoughts about having a ventilation system. They come with tons of benefits and round the year to provide the best possible protection for your home.

1. Proper roof ventilation will increase the lifespan of your roof. When the roof gets very hot on peak summer days, it gets heated up. Hot shingles will damage with prolonged exposure to the sun, so if you have a vent system in place, you can extend the life of your roof. During winter, if too much snow freezes over your roof, it could end up damaging the shingles. Both extremes of temperature can be avoided with ventilation.

2. A high-quality ventilation system will keep you cool and comfortable during summer. When the sun blazes down, don’t all want to remain indoors (and, of course, remain cool!). Roof vents pave the way for air circulation and will keep your indoor temperature chill. 

3. You can end up saving a lot on your energy costs by investing in a ventilation system. Efficient air ventilation will ensure that hot, high-pressure air goes out. There is no other way! What it means is that your air-conditioner does not have to work extra hard to cool your house.

Your attic will be chill and comfy, and your electric bills are reduced to a great extent. Moreover, you can avoid regular repairs on your air conditioner.  

4. Proper ventilation will make sure there are no extremes of temperature. It will also provide proper moisture control during the winter months. The latter means no damage to your roofs because of mold, mildew or water leakage. You can protect the health of your room and your family with an efficient ventilation system.


Want to get the most value out of your well-designed and carefully selected roof? Then install a proper ventilation system! This way, you will not just prolong the lifespan of your roofing system, but you will also be able to keep your home at a very comfortable temperature. Also, enhance the efficiency of your heating and cooling system, and shave a few dollars off your electric bill.

We hope this article will come in useful to pick the right roof ventilation based on the design of your roof and the style of your home. Good luck!

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