Roof Ventilation 101: Your Guide To Proper Roof Ventilation

Roof ventilation is a term that may sound familiar, but not everyone knows exactly what it means. So, when it comes to roof ventilation, there are three key things you need to know:

  1. It’s vital to prolong the life of your entire roofing system.
  2. Poor ventilation traps moisture which causes mold growth and water damage.
  3. Recurrent ice dams are caused by poor roof ventilation.

Today, we’ll expand on those and talk about everything you need to know about roof ventilation. You’ll learn how to do it, why it’s important, and bust a few myths along the way!

Roof Ventilation: Defined

Simply put, a roof vent will remove moisture and hot air from your attic. However, there are many different types of roof vents that can remove moisture and heat in various ways. But in the end, one thing is true: it’s critical to ensure your roof and attic stay at the right temperature and moisture-free.

There are two types of roof ventilation: exhaust vents and air intake vents. Each is valuable but varies in many ways. We’ll detail the differences and benefits of each below.

Exhaust Vents: Remove Moisture and Heat

An exhaust vent is designed to remove hot air and moisture from your attic. The most common type of exhaust vent is a ridge vent. Ridge vents sit at the peak of your roof and ensure any hot air rising to the top of the attic has a place to escape. 

Hot air contains moisture, so poor ventilation can create a very moist environment that can end up rotting and warping the wood in your attic. Other types of exhaust vents include:

  • Off-ridge vents
  • Box vents
  • Hard-wired powered vents
  • Solar-powered vents
  • Roof turbines (whirlybird vents)
  • Cupola vents
Off-ridge Vent

Intake Vents: Bring in New, Fresh Air

An intake vent is designed to bring in clean, fresh air from the outside. While exhaust vents are meant for removing moisture and heat, intake vents remove stale air that might be trapped inside your attic or roofing system and replace it with fresh outside air. They can also help reduce temperatures which will lower cooling costs during the summer months. 

The most common type of intake vent is your soffit vents. The soffit along the eaves of your roof ensures a steady flow of air is always coming into your attic space. Other common types of air intake vents include:

  • Gable vents
  • Over fascia vents
  • Drip-edge vents

Both exhaust and intake vents work in tandem to create a consistent airflow that keeps moisture out, air circulating, and allows proper temperature control in your attic.

Gable Vent

Roof Ventilation: Fact vs. Fiction

Some people may think that having vents in their attic means cold air will come into their home, and they’ll have to crank up the heat. This, among other myths, will get cleared up today. Roof ventilation is vital to your roof’s health and prevents expensive damage to your home.

Fact: Improper ventilation traps heat and moisture in the attic.

Heat doesn’t rise, but hot air does. And when hot air sits in your attic for an extended period of time, the built-up moisture also sits there and dampens wood beams, floorboards, and roof decking. 

That persistent moisture can cause mold growth in your attic or warp wood that is vital to ensuring your roof stays strong and secure. Thus, getting that moisture and hot air out of the attic is essential to temperature control and upholding the integrity of your roof.

Rotting attic due to humidity and growth of molds from poor ventilation

Fiction: My home’s ventilation was built to code, so it should be fine.

Codes change all the time. So even if your home was built a decade ago, your ventilation system must get updated to current codes and the proper amount for the size of your roof. The bigger your attic space, the more vents you’ll need. Make sure you find yourself a contractor who can help you get where you need to be.

Fact: Poor ventilation is the leading cause of recurrent, damaging ice dams.

Ice dams are huge, yes, dams of ice that build up on the edges of your roof during the cold months. But, no, it’s not because cold air is being let into the attic. It’s because the poor ventilation is causing an imbalance of warm air at the roof’s peak, with cooler air on the bottom. So when snow and ice melt at the top of the roof, it refreezes at the bottom, forming giant ice dams.

Ice dams are hazardous and damaging to your home. They are not like icicles but instead can get so heavy they tear off gutters, soffits, and even shingles. Plus, when the ice dams thaw in the spring, that water has nowhere to go but into your attic at the roof’s edge—causing extensive water damage to your home. 

So please, get the proper ventilation.

ice dam formation on home due to poor roof ventilation

Fiction: Having vents in my attic will let the cold air in and cool the house down.

And lastly, we want to reiterate that your roof vents are meant to circulate air in your attic and not your home. If your home and attic are well insulated on top of well ventilated, you should have no issues with heat or cold escaping from or entering your home. You will have more issues with high energy bills and inconsistent temperature with fewer attic vents and poor ventilation.

Signs of Poor Ventilation

We briefly touched on the signs of poor ventilation with our myth-busting guide, but there are a few other key signs to watch out for that can indicate a poorly ventilated roof.

  • Recurrent ice dams.
  • Excessive moisture and humidity in your attic.
  • Wet spots on the ceiling near your attic (can also indicate a roof leak).
  • Cold spots in the upper level of your home.
  • Deteriorating insulation from soaking up excess moisture.
  • Rusty attic fasteners.
  • Damaged or curling shingles.
  • Unusually high energy or heating bills.
  • Visible damage inside your home, like peeling paint or bubbled ceiling.
Woman Turning down thermostat because of high energy bills due to poor roof ventilation

Roof Venting Basics to Help Improve Your Home

Now that you know a bit of why you need roof ventilation let’s go over more of the basics of how it works, where it’s needed, and how it’s installed.

Airflow, Airflow, Airflow

The main thing to know is that roof venting is about getting proper airflow into the attic space. We’ve gone over what can happen when you don’t have it, but what happens when you do have it?

Proper airflow means consistent temperatures across your attic and in your home. It also means your home’s wood beams and structure stay dry and last much longer. 

Airflow will also ensure your shingles and roofing materials last as long as they intended, without having to work extra hard to insulate your home. And lastly, consistent airflow can protect any items or insulation you have in your attic that can get very damaged by trapped moisture.

exhaust vent installation for residential roof ventilation

How Do the Vents Work Together?

Like we mentioned above, your roof requires both intake vents and exhaust vents to work properly. The intake vents are most often near the bottom of your roof or attic, with the soffit being the most common place. Then exhaust vents are started at the top of your roof, either on or near the peak.

How it works is air flows into the air intake vents at the soffit vents, fills the attic space, and helps push out that stale, hot air out the top of your roof. This nice, even flow is what keeps everything working in tandem together. 

Both electrical powered and roof turbines move so they can actually enhance how much air gets sucked out of the attic. They are more expensive but can work wonders for larger attic spaces.

It’s worth noting that gable vents are a great way to let air in and out but don’t contribute to helping air flow throughout the attic based on their placement and design.

What Do You Need to Ventilate Your Roof?

There are many parts to a roofing ventilation system, and it’s good to know the names of each, so you know what you do or don’t need. Common ventilation parts include:

  • Continuous soffit vent
  • Turbine vent
  • Gable vent
  • Hood vent
  • Soffit vents
  • Round soffit vents
  • Ridge vent
turbine roof ventilation
Turbine Vent

Important Things to Know Regarding Ventilation

Like your home and roof, a bit of homeowner maintenance is required to keep things running smoothly and prevent any issues. The same goes for your roof ventilation system. The following important things to note are vital to keeping your vents clean and in working order.

  • Pairing insulation with ventilation is critical to really seeing cost-savings on bills. A properly ventilated attic is excellent, but without the insulation to support it, you might not see a big difference in your bills or temperature control inside your home, depending on the situation. So always make sure your attic is properly insulated as well, especially if insulation was damaged due to excess moisture.
  • Look into your shingles. Venting often shows the most benefit in hot climates where hot air gets trapped in the attic with nowhere to go. This heat can damage roofing shingles by prolonged exposure to high temperatures and moisture. Some shingle manufacturers might even void warranties if ventilation standards are not met or cause shingle failure. So make sure to pair your ventilation with well-installed shingles as well. The roofing system should work as a whole.
Roof Shingles damaged because of poor roof ventilation
  • You should have at least 1 square foot of vent area per 300 square feet of attic floor. More ventilation is never bad, but this is a general rule of thumb to follow.
  • Your vents can and will get clogged. Things like insulation, dirt, debris, cobwebs, and more can clog up your soffit vents. When you clean your gutters (which you should also do), you can also clean out your soffit intake vents. A light pressured air compressor can do the trick; just make sure to wear goggles!
  • If your roof gets damaged from a storm, it’s possible your vents did too. There are many pieces to your roofing system, from the shingles to the gutters to the flashing, and of course, your vents. The vents are often made of a light metal which is susceptible to dents and damage from hail. So if you ever experience a hail storm or extreme weather, make sure to check (or hire a professional) to look for damage on your vents.
damaged metal vent on brown home
  • Be mindful of how snow and ice melt on your roof. Comparing it to your neighbors is a good trick to see if your roof is well ventilated and insulated. In the winter, a completely bare roof among a bunch of snow-covered ones can be a good sign that you have too much heat escaping from your attic, thus melting the snow. This is also how ice dams form, so address it as soon as possible.

Now that we’ve covered everything you need to know about ventilation, you might be thinking, “Great; my roof isn’t well ventilated. ” That’s ok! We’re so happy we diagnosed the problem. Now, all you have to do is contact Apple Roofing.

contact roofing contractor for roof ventilation issues

Our highly experienced team of contractors can inspect your roof and help you get the ventilation, insulation, and shingles you need to get the ideal roofing system for your home. Contact us to schedule a FREE estimate for your next roof project.

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