To put it simply, roof ventilation is a system that allows air to circulate through the attic. Roof vents are essential to every home. Yet not many homeowners know much about their roof ventilation systems. Roof vents may not be something you necessarily think about, but it should be.
Roof vents help protect buildings in many ways. They extend the life of the roof, regulate indoor temperatures, and reduce the cost of energy. A well-vented attic will also protect buildings from damage caused by rot.
Let’s take a look at how attic ventilation works. We will discuss why ventilation is important and how it protects homes when installed properly. Hopefully after reading this guide, you will be more aware of roof vents and what they do.
What is Roof Ventilation?
Roof ventilation allows air to flow through the attic space, escaping through the roof vents. Properly installed roof vents will prevent the roof from overheating. They also prevent condensation from developing. When the roof overheats or moisture builds up, this can lead to substantial damage or health risks.
When ventilation systems that have not been installed correctly; this can lead to problems. These issues that develop can pose a serious risk to health and cause damage to the property. Some of the problems that can occur are mold growth, ice dams, and higher energy costs for the homeowner.
Roof Vents for Every Climate
Every home requires attic ventilation as it has a purpose throughout hot, cold, and mixed climates. And therefore, throughout every season. Vents work by clearing hot and wet air from the attic. As a result, homeowners can regulate the temperature of their home year-round. A well-ventilated roof will keep the temperature of the home comfortable and at the temperature you would expect for the time of year.
In cold climates, roof vents ensure that the attic is the right temperature. When it is icy, roof vents will prevent ice dams from forming. Ice dams develop over a short period when the heat of the sun and the warmth of the roof melt the snow and ice. This water then collects, refreezes, and creates puddles along the roof. Also, ventilation will allow any moisture in the air to clear from the living space below, escaping through the attic.
Ventilation is just as important in hot climates. When the weather is warmer, vents will work by clearing the hot air from the attic. As a result, this will cool the house and reduce the cost of running air conditioning systems.
Lastly, it is worth noting that before installing a ventilation system there are some things to consider. It is important to assess how airtight your attic is. We recommend sealing the attic floor or ensuring the hatch is as airtight as possible. If cold air can leak through into the levels below, this will contribute to energy loss. Energy loss will then lead to higher energy bills over time. Also, cold air seeping out from the attic may cause the temperatures in the attic to be too warm. This can lead to ice dams in cold seasons.
There are many types of roof ventilation systems. Some require electricity, some are powered by the wind, and some passively circulate air. Ventilation systems will only work when air can circulate. Here are the two main methods of creating a good airflow:
Mechanical – This method requires a power source and has moving parts.
Natural – Air can naturally flow through the attic, using the stack effect and the wind effect. We will discuss more on the stack effect and the wind effect a bit later.
Types of Roof Ventilation
The key to understanding attic vents is to be aware that there is no vent better than the other. As climates vary around the world and all homes are designed differently, roof vents need to be suited to each house. Therefore, you will need a custom ventilation system to suit your home. Here are some of the different vents there are out there:
Wind Turbines – It goes without saying that this type of vent relies on a constant source of wind. While the wind is blowing, Wind Turbines are a great option. But if your climate does not have much wind, this would not offer proper ventilation for your property.
Box Vents – Also known as Louvers, these types of vents are installed in a hole that is cut out of the roof. Box Vents allow hot air to rise and moisture to escape effectively as they are installed close to the roof ridge. The roof’s ridge is where most of the hot air will travel to escape through the roof naturally.
Soffit Vents – This type of attic vent is also referred to as eave vents. Soffit Vents are installed into the eaves and allow for air to flow through. Proper ventilation happens when the cool air can enter near the eaves and exit near the peak. And this is exactly how soffit vents (eave vents) work.
Ridge Vent – This attic vent works well alongside soffit vents. A Ridge Vent is a commonly used roof exhaust vent and should be installed along the entire roof’s horizontal ridge. This creates a far better appearance by allowing it to blend into the roof’s natural look. A roof Ridge Vent works by distributing hot and cold air, rather than creating hot and cold sections. By distributing temperatures along the roof, this prolongs your roof’s longevity.
Roof Vent Cap
As part of any roof ventilation system, a roof vent cap can help provide an escape for hot air. This escape of hot air also pulls cooler air inside, without the need for using a roof fan. Roof vent covers work at keeping moisture, rain, and insects out. At the same time, roof vent covers reduce your energy cost and reduce the temperature in the attic to keep your home comfortable. A Roof vent cap could be the ventilation solution you are looking for.
Power Vents require motors to power its large attic fan. A roof exhaust fan will work by pushing out the hot air and moisture through the attic. Some types of roof vent fan come with adjustable thermostats and humidistats to allow the homeowner to control when the attic exhaust fan turns on. The models with thermostats are more energy efficient because they only kick in when they are required. This means the roof fan is not constantly running and costing you money.
How Roof Ventilation Works
Now you know what roof ventilation is, we will now discuss in-depth about how the system works. Natural ventilation systems rely on air being able to naturally flow through the attic. This uses the stack effect and wind effect, but what are they?
The stack effect is when hot air rises into the attic, causing high pressure within the high points of the roof. Exhaust is when hot air escapes through the attic. However, the hot air can only escape when there is a way for cooler air to flow into the attic. Intake is when this cool air enters the attic.
When wind hits the roof from the outside, this increases the intake and exhaust, and this is known as the wind effect. Both intake and exhaust are important because they help encourage the natural circulation of air.
Whether you can use natural vents or require a mechanical roof vent, the idea is the same. Roof vents will work at allowing air to circulate the attic to regulate the temperatures.
But how many roof vents are needed? Having the right number of intakes and exhausts is essential to creating proper ventilation. Intake and exhaust both work together to manage the temperature within the attic and roof. You can never have too many, but you can have too little, so it is important to get it right.
A general rule is that a home needs one vent for every 300 sq. ft. Although, if there is no vapor barrier in the attic, the amount doubles. If your home has no vapor barrier in the attic, it is recommended to have one vent for every 150 sq. ft.
Benefits of Roof Ventilation
Roof ventilation is essential for every homeowner as it offers a range of benefits. Roof vents work throughout the year and in all climates to give your home the best protection.
Proper attic ventilation will extend the life of your roof by keeping the shingles cooler. In the warmer months, roof vents will allow air circulation so that hot air can escape. The attic and roof will both be kept much cooler, as a result. When the roof becomes warmer due to poor ventilation, this heats the roof shingles. When this occurs, the shingles become damaged.
Ventilation will also help homeowners to reduce their energy costs. When we enter the warmer months and summer begins, we want to keep cool inside our homes. A well-vented roof will allow the hot air to escape efficiently. As the hot air escapes, the attic is kept cooler and therefore reducing the strain on air conditioning systems.
Roof vents also help to reduce the extreme indoor temperatures. We have all walked upstairs to find it much warmer than downstairs. However, if this persists, it may be the result of a poorly vented roof. If hot air is unable to escape, it will stay in the upper levels of your home.
Problems from Poor Ventilation
Poor ventilation can cause many problems such as expensive damage and even health issues. Homeowners need to understand the adverse effects of poor ventilation. So, we will discuss a few of the issues that can occur when there is not sufficient roof ventilation.
During cold seasons, it is icy, cold, and may snow depending on your climate. Ice can build up on top of the roof, creating ice dams. Ice dams are created when the heat from inside the attic and the heat from the sun melt snow or ice. This water then collects at the edge of the roof and refreezes. This refrozen ice, then builds up behind and/or underneath the roof. Any further water that runs down to the edge will then be stuck behind the dam. When there is a build-up of ice, it can cause damage to the attic, walls inside the home, and the entire roof itself. Roof vents will allow the warm air to escape, not allowing it the time to melt the snow or ice.
While the build-up of snow and ice can sometimes pose a risk without proper ventilation, having no snow can also be a problem. If it is snowing heavily and snow has not been able to lay on your roof, this may suggest a ventilation issue. During the snowy seasons, a lack of snow can be a sign of poor ventilation. If your roof is warmer than it should be, due to poor ventilation, snow will melt quickly. We already know that this can lead to ice dams, so if you notice this occurring it is time to get a roofing expert in to assess your property.
When hot air is unable to escape through the roof, this can also create condensation. Moisture that forms will help produce rotting, which can lead to serious damage to the structure of your home. Condensation can also lead to water collecting and dripping down through the ceiling. This then causes further damage to the living space below. As your attic and home become damp, mold will start to develop and grow. Mold can potentially be dangerous and cause bad health problems for those living in the home.
We hope that you have found this guide on the importance of attic ventilation helpful. All homeowners and property owners need to understand what roof ventilation systemsdo. When roof vents have been installed correctly, all property owners benefit from them.
For expert advice on what types of roof vents will work best in your home, give us a call today. Our team will be happy to assist and help with your roof repairs or questions. Get in touch today for an estimate.