Your roofing system needs balanced attic ventilation in order to work at peak efficiency.
While replacing your roof, your contractor should provide you with a variety of ventilation options to choose from, ensuring that you have a well-balanced system of intake and exhaust vents.
Understanding the various types of roof vents required to build a balanced attic ventilation system will help you prepare to discuss ventilation choices with your contractor.
Find out why attic ventilation is so crucial for your roof and house.
Roofing and Attic Ventilation Products
Roof and attic ventilation solutions come in a variety of shapes and sizes. They’re commonly known as:
- Roof vents
- Attic fans
- Gable vents
- Louvers
Products for attic and roof ventilation fall into one of two categories:
- Intake ventilation
- Exhaust ventilation, or
- Both intake and exhaust
Why do I need intake and exhaust vents for my attic?
Every attic ventilation system should include a mix of intake and exhaust vents that are strategically located.
Roof vents and attic fans work year-round to:
- Remove warm, moist air
- Reduce condensation
- Keep your attic drier
- Allow pressurized heated air to escape so it doesn’t force its way into conditioned spaces
The key to ideal ventilation is having the correct amount of both types. Having only one or an uneven amount of one type of venting can lead to pressurization problems.
Big League Roofing Tip: Use the Ownes Corning Ventilation Calculator to help determine how much ventilation you need for your attic.
But, hey, it’s only the attic, so who cares?
Your attic space may be exposed to a piece or the full underside of your roof deck, depending on the form of your roof and the construction of your home.
Attics are frequently misunderstood as unconditioned storage areas. While this is true for some homes, particularly those with rafter-framed attics, some “attics” are little more than gaps between the ceiling and the roof deck. These spaces, whether large or tiny, require ventilation to control heat and moisture within the structure.
Moisture can build up in your attic if the quantity of intake roof ventilation is not properly balanced with the amount of exhaust roof ventilation, which can lead to a variety of issues, including:
- Mold
- Mildew
- Damage to the structural integrity of your roof
Big League Roofing Tip: Ask your contractor how to ventilate an area above a cathedral ceiling or other small attic space.
Intake Vents
Intake vents perform exactly what their name implies: they pull air in from the outside. This fresh air enters the attic and replaces the air that has been escaping through the exhaust vents, ensuring a balanced airflow.
Intake vents are commonly found beneath the eaves of a roof. They aid in the efficient operation of attic exhaust vents and aid in the reduction of energy expenditures.
Soffit vents and roof-mounted intake vents are the two types of 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 blends into the roofline.
Exhaust Vents
Exhaust vents allow air to escape from the attic to the outside. Exhaust vents, such as attic fans and ridge vents, are often located higher on the roof, frequently at the highest pitch, where hot air tends to collect.
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
- Dormer vents
Gable Vents
Gable vents, serve as both intake and exhaust vents, depending on wind direction and speed.
How Balanced Attic Ventilation Works
Let’s have a look at how balanced attic ventilation works now that you’re familiar with the various types of intake and exhaust ventilation equipment for your roof and attic.
Imagine it’s a hot summer day, and you’ve left your front door open to unload and bring groceries in from the car. There’s a breeze outside, and your house windows are open as well. The front door slams shut unexpectedly, likely frightening you.
What happened?
Your home was ventilating by pulling in air through the open front entrance to replace the air that was leaving through the open windows.
This is exactly what your intake and exhaust vents are doing in your attic. To begin, a vacuum is created by releasing air from the attic to the exterior through the exhaust vents. Then, through the intake vents, new air from outside rushes back in, filling the vacuum.
Air may be drawn from your living rooms to help equalize the pressure if you don’t have enough intake vents or if they’re clogged. Warm pressured air from the attic can also find its way into your conditioned living spaces if you don’t have enough exhaust vents. Both situations are inefficient in terms of energy use and may have an influence on your home’s energy bills.
If you’re continually tweaking your thermostat, you’ve got a problem.
The Bottom Line
As you can see, balancing is a vital idea in optimal roof ventilation. You’ll need the right number of intake and exhaust vents to ensure balanced airflow in your attic areas. Intake and exhaust vents on the roof work together to remove warm, moist attic air and replace it with fresh, dryer air. The air pressure is maintained throughout the procedure.
Consult a roofing contractor if you see any indicators of poor ventilation in your home. They can examine for airflow obstacles and determine whether or not you require more vents of various types. Before starting a roof replacement, make sure to talk to your roofing contractor about ventilation options.