If you’re investing thousands into solar panels in Ottawa, your attic’s airflow might be the one thing silently draining your system’s efficiency.
When people think about solar energy, their minds usually jump straight to the panels — those shiny rectangles soaking up the sun. Fair enough. They’re the stars of the show. But what’s going on underneath them is just as important, and often overlooked.
Airflow in your attic isn’t the most exciting topic, but it plays a big role. It helps your roof breathe, keeps moisture out during the cold months, and stops heat from piling up when it’s hot outside. Without that balance, even the best solar setup can run into trouble.
At True Beacon, we’ve inspected hundreds of rooftops across Barrhaven, Kanata, and Orleans. What we’ve found? Most solar installs skip one crucial step: checking whether the attic can handle the heat.
What Is Roof Ventilation and Why Does It Matter?
Ventilation is how your attic breathes. Cooler air comes in through vents near the bottom of your roof—these are called soffit vents. Warmer air escapes through vents closer to the top.
This moving fresh air isn’t just for comfort. It helps your attic stay cool during the summer heat. It also prevents moisture buildup in winter, which can lead to mold growth or wet spots. And it helps stop ice from forming along the edge of your building roof. That’s what we call ice dams. Plus, it protects your shingles and the wood underneath from wearing out too fast.
But when air can’t flow, problems start. Heat gets stuck in your attic. In winter, that warm air rises and hits the cold roof. Water forms, then soaks into wood and insulation. In summer months, all that trapped heat just builds up. It makes your house harder to cool and can even hurt your solar panels’ performance.
Ice dams are another big sign of bad airflow. Snow melts too fast near the warm parts of your roof and freezes again before it can run off. Water backs up under your shingles and causes leaks.
Good airflow keeps your roof and attic balanced. Without it, your home can run into big problems over time. With it, your roof stays stronger and your solar power system works the way it should.
Solar roof ventilation systems can reduce a home’s cooling costs by up to 30%.
How Bad Ventilation Hurts Solar Panels
Solar panels don’t float in the air — they’re mounted just a few inches above your roof. That small space in between can trap heat, especially when the sun’s beating down. If the attic under your roof can’t move air properly, the heat has nowhere to go. And that’s when things start to go wrong.
Excessive heat in the attic isn’t just uncomfortable. It wears down your roof and hurts your solar system’s ability to do its job.
Here are some of the problems we’ve seen again and again:
- Shingles curling up, cracking down the middle, or wearing out way too early
- Insulation that looks clumpy or damp — often from moisture accumulation
- Mold spots on the wooden boards inside the attic, especially near nails or seams
- Ice dams forming at the roof’s edge in winter, causing water to get pushed back under shingles
- Older homes where someone put panels right over the vents, trapping hot air inside for good
These issues don’t just cause trouble. They can get pricey, fast.
The frustrating part? Most of it can be avoided. A quick check of your attic and roof before the panels go up could stop these things from happening later.
But when that step gets skipped, things snowball. What starts as a bit of heat turns into cracked shingles, leaks, or mold. All of it takes time and money to fix.
It’s not just about having solar panels. It’s about making sure your roof and attic are ready to support them — without falling apart.
A Missed Vent in Limoges Cost a Family $4,000
A homeowner in Limoges installed a 5kW solar system without adjusting attic ventilation. Six months later, attic moisture had warped the plywood decking and mold started spreading.
A single plastic vent had been covered by panels. Replacing the vent, removing mold, and re-installing part of the array? $4,000.
Lesson: even one blocked vent can offset the gains from solar.
Let’s Talk About Ice Dams (They’re a Bigger Deal Than You Think)
You’ve probably seen them — thick chunks of ice lining the edge of a roof, maybe with long icicles hanging down. They might look kind of nice, like something from a holiday card. But in real life? They’re trouble.
Here’s what goes on: heat escapes from your attic and warms up the roof. That melts the snow sitting on top. The water runs down the roof, but when it hits the colder edges, it freezes again. Bit by bit, a wall of ice forms near the edge. That’s the dam. And the water behind it has nowhere to go — so it slides under the shingles.
Then come the leaks. Water drips into the attic. Ceilings get wet. Wood starts to rot. Your insulation turns soggy. One small issue turns into a bunch of bigger ones.
This is pretty common in Ottawa. The mix of snow and freezing temperatures makes it worse, especially on older homes with weak airflow up top.
But here’s the thing: ice dams don’t have to happen.
What helps the most is keeping your attic cold in winter. You want the space inside your roof to stay close to the outside air. If it stays cold, the snow doesn’t melt. It just stays frozen and quiet up there. To get that right, you need good airflow and solid insulation. Vents move air in and out. Insulation keeps heat in your home instead of leaking into the attic.
We also add ice and water shield along the bottom of the roof. It’s a sticky barrier that blocks water if it starts to sneak under the shingles. It’s not a fix for poor airflow, but it gives you a backup layer of protection.
So, if you see thick icicles or chunks of ice near your gutters, don’t wait. That’s your house warning you. It’s best to take a closer look — before that little dam causes a big mess.
Don’t Cover Vents — Let Them Do Their Job
It happens a lot. Someone adds solar panels and places them right over the vents. The vents stop working, air can’t move, and moisture gets trapped. That’s when the problems begin.
If your roof still has those short plastic vents, they’re likely not helping much—especially in winter. Around Ottawa, snow piles up and covers them for weeks. Once that happens, flow of air slows down, and warm air inside starts to cause moisture to form.
We recommend swapping those out for tall steel vents like the ones made by Maximum. They’re built to stick up high, so snow doesn’t block them. Their shape helps pull warm air out of your attic without needing fans or power. They just work. Simple, solid, and quiet.
Most of these roof vents can handle between 800 and 1,000 square feet of attic space. Smaller homes might only need two. Bigger ones could need more. We check that during your roof visit.
Now, about powered fans—people think they help, but we don’t use them. Fans can stop working overtime. When that happens, they don’t just stop helping. They can cause more trouble. Passive vents just move air on their own, with no wires and nothing to fix later.
So if you’re getting solar, don’t trap heat under those panels. Give your roof a way to breathe. It’ll last longer. And your solar system will work better too.
How Much Does It Cost to Fix Ventilation?
Upgrading vents doesn’t cost much, especially when you compare it to what could go wrong without it.
Most steel vents cost a few hundred dollars each to install. The final cost depends on how many you need and how your roof is built.
Now think about what you’d pay if moisture or heat caused damage:
- Mold cleanup: $1,500 to $5,000
- Fixing a roof leak: $800 to $2,500
- Full roof replacement: $10,000 or more
A few vents now can save you thousands later. And if you’re already doing solar, the labor is already there—so adding vents won’t break your budget. One job, one team, done right the first time.
Does Roof Color Matter? Not Really.
Some people say light roofs help keep your home cool. That’s true to a point, but not the whole story.
What really helps is airflow. If your attic has good ventilation, the color of your shingles won’t change much. So pick the color you like. What’s underneath matters more than what you see from the street.
What We’ve Seen Around Ottawa
We’ve worked on rooftops all across Ottawa — townhouses in Barrhaven, family homes in Orleans, rural builds out in Limoges and beyond. The difference a well-ventilated attic makes? Night and day.
Here’s what our clients get when the airflow’s handled right:
- Cooler summers upstairs. That means less heat is trapped in your attic and better performance from your panels.
- Fewer winter surprises. Ice dams are way less likely when warm air isn’t sitting beneath your roof.
- Drier insulation and framing. That keeps mold out and wood rot from sneaking in.
- Fewer worries all around. When your attic and roof are in sync with your solar system, everything just works better.
How True Beacon Takes Care of Roof Ventilation
We Look at More Than Just Solar Panels
At True Beacon, we don’t just focus on installing solar. We also inspect your roof carefully, especially the ventilation system.
We Check for Heat and Moisture
We inspect your attic and roof for signs of trapped air, heat, or moisture. If we find anything off, we will walk you through it step by step.
We Don’t Block Vents — We Move Them
If a panel needs to go where a vent is, we don’t cover it. We move the vent instead, so your attic still gets the airflow it needs.
We Give You Written Proof
Any vent work we do comes with documentation. This helps with warranty claims or insurance down the road.
It’s About More Than Just Solar
We don’t just want your panels working well—we want your whole roof to stay in good shape for years to come.
Check Your Roof Before You Add Solar
Before you think about panels, look at what they’ll sit on.
We’ll come out and check your roof and attic for free when you book a solar consultation with us. We’ll look at your vents, your insulation, and your roof’s shape.
If something needs fixing, we’ll explain it clearly. No pressure. Just honest info you can use.
? Call us at 613-701-1028 or visit truebeacon.ca to book your checkup.
Frequently Asked Questions
Why does ventilation matter when installing solar panels?
Airflow in your attic helps keep your home cooler in the summer and drier in the winter. If air can’t move, heat and moisture build up. That can wear down your roof and hurt how well your solar panels work.
Can poor attic ventilation damage my solar panels?
Not right away. But if your roof gets too hot under the panels, they won’t work as well. Over time, the extra heat can make them less reliable and may cause problems with your roof, too.
How do I know if my attic has enough ventilation for solar?
You’ll need someone to check it. Signs of poor airflow include damp insulation, dark spots on the wood in your attic, or ice forming along your roof’s edge during winter.
What type of vents are best for snowy areas like Ottawa?
Steel tower vents are a good pick. They’re tall, so they stay above the snow, and they keep air moving through your attic all year round.
Will solar panels block existing vents on my roof?
They shouldn’t. A careful installer will avoid placing panels over vents. If the vents are in the way, they’ll move them to a better spot so air can still flow.
Is ventilation part of the solar installation process?
It should be. At True Beacon, we always check your attic and roof before we start. If you need new vents or changes, we will let you know that before the panels go up.
Do attic fans help with solar panel performance?
Yes, attic fans can help reduce heat buildup by pulling hot air out of your attic. This lowers the temperature under your roof, which helps solar panels work better and supports more stable indoor temperatures.
How does good ventilation support renewable energy at home?
When your roof and attic are well-ventilated, your solar panels can produce more clean power. That means you get the most out of your renewable energy system while using less power from the grid.
Can better airflow help lower my energy bills?
Yes. Good airflow helps reduce heat transfer into your home, which keeps it cooler in summer. That means your AC doesn’t have to work as hard, lowering your energy consumption and cutting down on monthly utility bills.
Why is regular maintenance of vents important for solar homes?
Blocked or damaged vents can trap moist air in your attic, which hurts indoor air quality and can lead to moisture damage. Keeping your vents clear helps with overall efficiency and supports long-term energy savings.
How does roof ventilation affect my home’s energy efficiency and costs?
Good ventilation helps your home stay cooler in summer and drier in winter. That means your heating and cooling systems don’t have to work as hard, which improves energy efficiency and can lower your energy costs over time.