Skylights are a great way to fill your home with natural light and add a touch of modern style. However, many homeowners in the Greater Toronto Area (GTA) notice water forming on their skylight glass — especially during the colder months.
At first, it might look like a leaky skylight, but that’s rarely the case. In most situations, the problem is condensation caused by warm, moist indoor air meeting cold glass. At Awash Roofing, your trusted Toronto roofing experts, we understand how frustrating this can be. Here’s why it happens and how you can stop it.
Skylights brighten your home and make spaces feel open and inviting. However, many homeowners across Toronto and the GTA notice moisture forming on their skylight glass — especially in winter.
This isn’t always a leak. Most of the time, it’s skylight condensation, caused when warm indoor air meets cold glass. The temperature difference makes water vapor turn into droplets.
It’s important to know the difference between condensation and a real leak. A leak often leaves streaks, water stains, or dripping water, while condensation looks like fog or small droplets inside the glass. Over time, heavy condensation can still cause mold or wood damage, so addressing it early is key.
Toronto experiences cold winters and warm, humid summers, creating constant temperature swings. During cold months, the warm air inside your home rises and meets the cold skylight glass — perfect conditions for condensation.
Modern homes also tend to be airtight and well-insulated, which helps save energy but traps moisture indoors if ventilation is poor. Everyday activities like cooking, showering, and drying clothes can increase humidity, leading to condensation buildup on skylights.
If your skylight shows moisture often, it’s a sign that your home’s humidity or ventilation needs balancing.
Good airflow prevents moisture buildup.
Use bathroom and kitchen exhaust fans during and after showers or cooking.
Keep doors open to let air circulate.
Consider a Heat Recovery Ventilator (HRV) or Energy Recovery Ventilator (ERV) for consistent air exchange.
Even briefly opening windows can help — just a few minutes can reduce humidity indoors.
Too much indoor moisture encourages condensation.
Use a dehumidifier in high-humidity rooms.
Monitor humidity with a hygrometer; aim for 30–50% relative humidity.
Avoid drying clothes indoors when possible.
Cold air leaks can make glass surfaces chill faster.
Inspect for gaps or cracks around the skylight frame.
Re-seal with weatherstripping or caulk if needed.
Make sure the light shaft leading to the skylight is properly insulated.
If you’re replacing or installing a new skylight, pick double- or triple-pane glass with argon gas and Low-E coatings.
These features help maintain a warmer inner glass surface, reducing the temperature difference that causes condensation.
Clean the glass often to prevent dust from trapping moisture.
Schedule a roofing inspection once a year. The experts at Awash Roofing can check for leaks, insulation gaps, and potential ventilation issues.
At Awash Roofing, we provide trusted roofing services in Toronto and the GTA, helping homeowners keep their roofs and skylights in top condition. Our team uses durable, weather-resistant materials and proven installation methods to deliver long-lasting results.
From roof repairs and replacements to skylight installation and maintenance, we focus on quality, honesty, and customer satisfaction. Whether you need a small fix or a full roofing project, we’re here to help protect your home year-round.
Check out our recent projects to see the quality of our work: https://awashroofing.ca/projects/
1. Is skylight condensation normal?
Yes, mild condensation is common, especially in winter. But persistent moisture may mean your humidity or ventilation needs adjustment.
2. How can I tell it’s not a leak?
Leaks usually cause dripping water or stains, while condensation looks like fog inside the glass.
3. Can condensation damage my roof?
If left untreated, moisture can lead to mold, paint damage, or wood rot around the skylight frame.
4. Do you provide skylight repair services in Toronto?
Yes! Awash Roofing offers professional skylight inspections, repairs, and replacements throughout Toronto and the GTA.
5. How often should skylights be inspected?
We recommend checking them once a year or after major weather changes.
Skylight condensation is common but manageable. With proper ventilation, insulation, and maintenance, you can enjoy bright, clear skylights all year long.
If you’re unsure whether you’re dealing with condensation or a leak, contact Awash Roofing — your reliable Toronto roofing experts. We’ll inspect your skylight and help you keep your home safe, dry, and energy-efficient.
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