Why Are Roofing Vents Important?
Your roofing system needs balanced attic ventilation to perform at its best. When you’re
replacing your roof, ask your roofing contractor about ventilation options for your roof and
attic. They should offer several ventilation products for you to consider, ensuring you have a
balanced system of intake and exhaust vents.
Be prepared to discuss ventilation options with your contractor by understanding the different
types of roofing vents necessary to create a balanced attic ventilation system.
Depending on the shape, size, and materials of your roof and architecture of your home, either
a section or the entire underside of your roof deck is exposed to your attic space.
Attics may often be seen as unconditioned storage spaces. While that may be true for some
homes, especially those with rafter framed attics, some “attics” are little more than gaps
between the ceiling and roof deck. Big or small, these spaces need venting to manage heat and
moisture inside the structure as well.
Without correctly balancing the amount of intake roof ventilation with exhaust roof ventilation,
moisture can build up in your attic, leading to a potential host of problems, including:
- Mold
- Mildew
- Damage to the structural integrity of your roof
How Balanced Attic Ventilation Works
Let’s first take a quick look at how balanced attic ventilation works. Imagine it’s a hot summer
day and you leave the front door of your house open so you can unload camping equipment
from your car. Your house windows are also open, and there’s a breeze blowing outside.
Suddenly, the front door slams shut. Why does that happen? Your home was drawing in air
through the open front door to replace the air leaving through the open windows. In
other words it was ventilating.
This is exactly what is happening in your attic through your intake and exhaust vents. First, air is
released from the attic to the outdoors through the exhaust vents, creating a vacuum. Then,
fresh air from the outside rushes back in through the intake vents, filling the vacuum.
If you don’t have the right amount of intake vents or if they’re blocked, air may be pulled from
your living spaces to help balance the pressure. Likewise, if you don’t have the right amount of
exhaust vents, warm pressurized air from the attic can make its way into your conditioned living
spaces. Both scenarios are not energy efficient and can potentially impact your home’s energy
costs. If you find yourself constantly adjusting your thermostat, then you may have a ventilation
issue.
Different Types of Roofing Vents
Intake Vents
Intake vents do just as their name suggests — they take in air from the outdoors. This fresh air
goes into the attic and replaces the air that went out from the exhaust vents, helping to ensure
balanced airflow.
Intake vents are typically placed under the eaves of the roof. They help the exhaust vents in the
attic do their job more effectively and assist in controlling energy costs.
There are two types of intake vents: soffit vents and roof-mounted intake vents.
Soffit Vents
Soffit vents are the most common type of intake roof vents, and they’re placed underneath the
roof eaves all along the length of your house or between the joists.
Roof Intake Vents
If your home has no soffit or exposed rafters under the eaves, a roof mounted intake vent can
be used to provide adequate air intake. These vents have a low profile that blend into the
roofline.
Exhaust Vents
Exhaust vents allow air to flow out of the attic to the outdoors. Attic fans and ridge vents are
two examples of exhaust vents, and these are typically placed higher on the roof, often the
highest pitch where hot air tends to gather.
Ridge Vents
Ridge vents, as the name implies, run along the very top of a roof on the ridge, typically where
the two sloping portions of a roof meet. They’re ideally placed to catch the wind blowing over
the roof, which helps expel moisture and heated air from the attic.
Static Roof Vents or Roof Louvers
Static roof vents or roof louvers permit air to escape the attic and are placed flat on the roof
and evenly distributed near the ridge.
You might find these listed under various names depending on the region in which you live,
such as:
- Slant-backs
- Box vents
- Turtle vents
- Half-rounds
- Off-ridge vents
In the western U.S., they’re frequently called dormer vents.
Wind or Roof Turbines
Wind or roof turbines have blades or vanes built in. The wind turns these blades, creating a
spinning vacuum that helps draw out hot, moist attic air.
Attic Fans
Attic fans are typically located on a wall inside the attic. Their job is to pull air from the attic and
vent it to the outside. Attic fans can move large amounts of hot or humid air from an attic,
which can help keep your heating and cooling costs in check. Homeowners can gain more
control over ventilation by turning attic fans on and off as needed.
Powered Roof Vents
Powered roof vents work on the same principle as fans. Although a more expensive option,
powered roof vents can be configured to run off electrical or solar power. The added
mechanical force behind these roof vents can significantly increase air circulation, potentially
saving you money in the long run.
Gable Vents
A few vents, such as gable vents, serve as both intake and exhaust vents, depending on wind
direction and speed.
Roofing Vents: The Bottom Line
The key concept in proper roof ventilation, especially in Vancouver, is balance. To achieve
balanced airflow through your home’s attic spaces, you need the correct amount of intake and
exhaust vents. Roof intake and exhaust vents work together to help remove warm, moist attic
air and replace it with fresh, drier air while also trapping in hot air during cold months. In the
process, air pressure remains equalized.
If you notice any signs of improper ventilation in your home talk to us at Cambie Roofing. We
can check for airflow obstructions or see if you need additional vents of one type or another.
Also, make sure to discuss ventilation solutions with your roofing contractor before beginning a
roof replacement.