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How to Fix Skylight Leaks

How to Fix Skylight Leaks

August 5, 2022

Let the sun shine in with a skylight, they were created to bring natural light to rooms that couldn’t accommodate a wall window, and they have been gaining popularity. But on occasion, a skylight leak has caused a situation where a skylight leak repair in Toronto becomes necessary. Like everything, skylights are flawed, and cutting a hole in your roof to install one exposes your roof and the layers of insulation to the elements. Seals fail, and leaks start. As soon as you see this, it is important to act on the problem, so it isn’t exasperating. At Integrity Roofers, we’d like to share our professional advice on dealing with skylight leaks and how to stop them.

How to Diagnose Skylight Leaks

Before you contact a roofing contractor, check a few things upon discovering water around your skylight. Look to see if the skylight is completely closed – it may be jammed and slightly open, allowing water to enter. Ask yourself, is my skylight close to a bathroom or kitchen? If so, is the water I see condensation from cooking or a long shower? If your problem is condensation, try to vent the area better to allow the moist air to escape. Another problem for skylight owners – newly installed – is poor sealing around the skylight. A lack of a watertight seal will help water enter, and the skylight will need to be resealed to prevent water from entering your home. It might sound odd, but inspect it from the outside when looking for a skylight leak. Douse the skylight with a small stream of water to find the entry point. That way, you have identified the problem area and can act accordingly.


If you have a water vapour film, it will condense on your skylight. Generally, the vapour will concentrate at a low point and drip to the floor. To remedy this problem, you need to improve the ventilation around the skylight.

If your skylight doesn’t open, consider a fan to move the water vapour or remove sediment from the weeping holes outside the skylight – the holes allow condensation to vent – and the clouding you see on the skylight will be reduced.

Faulty Skylight

If you have a skylight leak, it may be a gasket problem. The skylight may not close properly if the gasket has debris or mould encrusted. Moisture enters between the window casing and the frame, a problem for sure. Replacing the gasket may be the solution here. If you have a crack in your skylight, it could be the source of the leak, and replacing the skylight is the best course of action.

Faulty Roof Flashing

By process of elimination, you have ruled out condensation or a defective skylight. The only thing left is water entering the roof structure. Your roof flashing or the skylight flashing may be compromised. Water follows gravity, so a leak will roll down the decking from an upper penetration. If the leak is on a lower roof section, it could come from anywhere. If the leak originates in the upper regions of the roof, it is the skylight.

Water Sealant can Wear Away.

Your skylight and windows share a common denominator: both have sealants to keep the area waterproof. Like anything, sealants are known to erode over time and need a replacement bead to keep water out. Replacing the sealant or adding a layer of caulking might just fix the problem, and the solution is easy to administer.

Reseal the Flashing

If you determine the source of your skylight starts at the flashing, you need a caulking gun, a ladder, and an industry-approved sealant. To achieve the repair goal, look at the skylight and area for fragments of old sealant and lift roof shingles in the area to look for water stains beneath. Add sealant to all areas that look compromised – don’t scrimp on sealant – and lastly, add a healthy dose of sealant at the head of the skylight.

You May Need to Reinstall the Flashing

If you don’t have an experienced contractor installing your skylight, you could end up with faulty workmanship, creating the need for flashing reinstallation. Flashing is never to be nailed to the roof – it makes an opening for water leaks – Rusted flashing needs to be replaced; it is failing and is one storm away from high volume leaks. An experienced contractor should be able to meet the challenge, better penny-wise than dollar foolish. A few bucks on a small repair saves a substantial roof repair or replacement cost.

When Is It Time to Replace Your Skylights

How Old is Your Skylight

Skylights, like roofing systems, have a shelf-life. Your skylight should last 15-20 years. If the term is close, you might want to replace the skylight, especially if you are doing a re-roof. If the skylight is on the new side – say 3-5 years old – a repair could be in order.

How Tight is Your Budget

The difference between reflashing your skylight and complete replacement is in the hundreds of dollars. Sure, money is tight, but the extra dollars you spend now might be realized in savings from avoiding a costly roof repair because you had a leaky skylight.

What Does Your Roofer Recommend

A little professional advice can go a long way. Most roofing contractors will be cautious and say the replacement is best to keep leaks under control. Reflashing your skylight may be an option if the skylight is less than five years old.

Skylight Repair Vs. Replacement

If skylights are jostled/disturbed during re-roofing, they can develop a leak. If you have the budget replace the skylight when upgrading the roof. Depending on the age of the skylight and the money available, you may not need the added expense of a new skylight. Check with your roofing contractor to determine the best course of action.

When to Call a Skylight Leak Repair Profesional

If you can’t identify the source of the leak, don’t go looking for it by walking around on the roof. Your leak problem might be as simple as a sealant replacement or much more complicated. Let a professional apply an expert diagnosis, and they have the experience to spot what a homeowner can not. Inexperienced help creates more problems later, and those problems come with a monetary price.

Schedule Skylight Leak Repair With Integrity Roofers

How to Fix Skylight Leaks We use industry-standard materials and techniques for all repairs to give you a top-flight skylight repair. Our service is second to none based on our years of experience dealing with roofing and skylights. We provide an array of skylight repair and installation services, and we have worked with many different shapes of skylights, so we have seen it all. For all your skylight repair needs, call our office at 647.953.9365. Or, fill out an estimate form on our site, and we will respond promptly.

Also Read: How Does A Skylight Leak Damage the Roof?

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