Why your Skylight is Leaking and What to Do About It

You’ve put up a glass skylight in Sydney to enjoy more natural light, increase the ventilation in your home, and reduce your energy costs.

It probably also gives your home in Sydney NSW some visual appeal that makes it a more attractive place to stay in.

But now, you’ve noticed some water damage around it. And you are wondering why it happened and how to deal with it.

Let’s discuss this problem and find solutions.


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Generally, skylights are meant to last for up to 20 years. Most of them come with a warranty that guarantees durability.

However, skylights can fall into disrepair before the warranty period is over. Why, you ask?

Well, from the day you install a skylight, it is exposed to rain, snow, and debris that can damage it.

And if it is improperly installed or poorly maintained, a skylight will age faster than you expect.

Therefore, if your skylight is leaking, it’s not a rare or abnormal occurrence. You can fix it!

The first point of call is finding out why your skylight is leaking. And here are a few possibilities.


7 Reasons Your Glass Skylight in Sydney is Leaking


  1. Bad installation

Sometimes, installers do not put up a skylight correctly, and that will obviously lead to problems.

Installation issues may crop up due to;

  • Putting up the skylight at the wrong pitch thereby preventing proper drainage of rainwater or condensation
  • Wrongly flashing or insulating it leaving sections of the skylight such as seams open to leakage
  • Damaged surrounding roofing material, such as tiles or shingles which negatively affects the performance of the skylight


  1. Wrongly operating a skylight

Sometimes, we forget how to properly operate a skylight which can cause leaks.

For example, simply forgetting to close a venting skylight will let water into your home.

And if debris such as leaves stick into the drainage channel of your skylight, it may prevent it from closing completely, thereby allowing water to flow in.

Such scenarios often occur when the skylight is too high up, which keeps us from seeing if it is tightly shut.

Therefore, you should check if your skylight is fully closed before looking for other causes of your leakage.

Also, watch how you operate your skylight, ensuring you handle it with care to maintain it in good condition.

For instance, carelessly opening and closing a ventilating skylight can cause unnecessary wear and tear that will lead to air and water leaks.


  1. Condensation

Skylights will sometimes drip due to a collection of moisture on the inside caused by condensation.

You can expect condensation on your skylight if it is single glazed or installed over a humid room such as your kitchen.

Hosing down your skylight by passing water over it and the surrounding areas will help you determine if the leakage is caused by condensation.

It may also help you to find the point from which it is leaking.

Some common leakage points are the sealant, flashing, and old areas of the surrounding roofing material, such as the shingles or tiles.

Your skylight may also leak from a crack in the glazing itself.

If you cannot identify the point from which your skylight is leaking, ask an expert to diagnose the problem for you.


  1. Worn out roof sections

If the roof sections surrounding your skylight are in bad condition, it may cause a leak.

For example, where there are worn-out shingles, You will find spaces that water can pass through, causing your skylight to leak.

Hairline fractures in the glazing of your skylight from snow or hail damage may also contribute to water damage.

If the insulation around your skylight is damaged, which often happens due to old age, it could let in water too.

And often, when the weep holes around your skylight are clogged by debris, you can expect water or condensation to leak back into the home.

Therefore, it’s always wise to check the integrity of your roof when looking for leaks on your skylight to eliminate wear and tear as a cause.


  1. Poor flashing

Flashing is meant to lead water away from your skylight. It seals the area between your roof and the skylight preventing any water from leaking into your house.

Any corrosion or damage in your flashing will cause your skylight to leak.

Such issues are common with deck-mounted skylights because they lay flush against the roof surface.

Curb-mounted skylights are less likely to leak as they come with flushing and are often fixed to the roof surface by counterflashing.

Therefore if you have a deck-mounted skylight, the flashing is the first place you should check for damages that may cause your skylight leakage.

Sometimes, skylight contractors fashion their own flashing instead of using a factory flashing kit.

Such flashing is unlikely to withstand the test of time and often results in leaks.

If your installer has taken this approach, you can almost bet your skylight is leaking due to their low standard workmanship.


  1. Rotten or rusty framing

When your skylight frame is in disrepair, it may cause leakage.

Some frames are made of wood which may rot with time opening up spaces for water to drip through your skylight.

Those made of aluminum may also corrode due to longstanding water damage or a collection of debris stuck around them that leads to rusting.

Therefore, check your framing for integrity issues when looking for leakage as it is a likely problem area.


  1. Damaged glazing

Glazing or the glass panes in your skylight can also let in water if the weatherproofing around it is broken.

If weatherproofing is an issue, expect your skylight to discolor or get foggy.

Also, understand that sometimes skylight glass planes develop tiny cracks invisible to the eye, which let water in.

Although it’s hard to identify cracks in a skylight glass plane, you should think of it as a possible cause of your leaks if you’ve recently experienced harsh weather that has exposed your skylight to hail and debris.


How to fix a leaking skylight

Now that you know why your skylight is leaking, how do you fix it? Here are some suggestions.


  1. Seal any leaks

The best skylight sealant is waterproof sealant such as clear proof silicone or roofing cement sealant.

You can use it to fix minute cracks on your skylight glass and spaces around the framing or flashing.

You can also use expanding polyurethane foam to close up any gaps in the insulation around your skylight.

However, a better solution is to reflash your skylight entirely with a new kit to ensure you don’t worry about leaks for a long time to come.

And, if the shingles around your skylight are cracked or lifted due to moisture damage, nail them back down or replace them with new ones to keep the issue from affecting your flashing.


  1. Solve humidity issues

Humidity causes condensation when hot air hits the cool surface of your skylight, forming droplets that fall back into your home as leaks.

You can prevent such humidity problems by ventilating hot rooms in your home by opening window blinds or using fans.

Unclogging existing weep holes and opening vents in your loft will also give the hot air in your home an outlet.

You could also apply an anti-fogging product to your skylight glazing to keep condensation from sticking onto the glass panels.


  1. Adjust or replace your skylight

If your roofer made a mess of the installation process leading to leaks, adjusting your skylight may stop the problem.

However, you should not wait for too long after a bad installation to fix your skylight; otherwise, you risk extra repair costs.

You could also install a new skylight if yours is too old for repairs.

Although experts advise us to install skylights when putting up a new roof, you can install a new skylight onto an old roof if you hire an expert roofer for the job.

That’s because they will choose the right place to install it, cut into the roof with care, and seal or flash it correctly, leaving the roof in excellent condition.


How much does it cost to repair a skylight?

Now that you know how to deal with your leaking skylight, maybe you are wondering about repair costs.

Here are some factors that will determine how much you pay to repair your skylight.


  • The extent of the damage

If your skylight only requires resealing, it won’t cost you as much as replacing the glazing. Resealing a skylight will cost you between $300 and $500.

Replacing the glazing with strong double-paned skylight glass that comes with a 10-year warranty will cost you between $300 and $800.

However, if the cost of repairs such as resealing or reglazing is too high, you may choose to install a new skylight which will cost you between $1000 and $2000.


  • The type of skylight

Is your skylight fixed or vented? Fixing a venting skylight usually costs more than repairing fixed ones because you have the opening mechanisms to consider.

Usually, fixing sealant or flashing issues will only cost you between $300 and $500.


  • The cost of labor

The best person to repair your skylight is a roofing expert because they have knowledge on how to safely and correctly install a skylight.

A roofing expert who can install skylights will maintain the integrity of your roof, ensuring you do not void your warranty while properly putting up the skylight or repairing any damaged areas.

Generally, the minimum amount it will cost you to hire a roofing expert to repair your skylight is $ 300.

And in the case of electrical skylights, you may have to replace the wiring, which will require the services of an expert electrician who may charge you between $160 and $500.


Do you want to repair your skylight?

Maybe you feel repair costs for your skylight are too high, and you’ve decided to repair it yourself.

While it may work, know that most DIY repairs often worsen issues or solve them for a very short time before it recurs.

Hire a roofing expert to repair your skylight will protect your surrounding roof from unnecessary damages and ensure that repairs are done correctly.

However, the best thing is to invest in a reliable skylight from the start that comes with a no-leak warranty.

Such warranties guarantee proper flashing and skylight installations that will prevent leaks for a long time.

Therefore, if you are putting up a skylight, choose one with at least a 10 year no leak warranty to avoid leakage issues.

Once you install the right skylight or repair an existing one, do not forget about maintenance.

That means cleaning your skylight regularly to clear out debris and accumulated films of dirt that will keep it from performing excellently.

You should also perform periodic inspections of your skylight to check for leaks and repair issues.

Once you identify any problems, deal with them immediately, and your skylight will last for a long time.



In summary, here is what to do if your skylight is leaking;

  1. Find out whether it’s leaking and, if so, why?
  2. If your skylight is leaking, calculate the costs of repair.
  3. If the cost of repairs is not too high, call a qualified roofing expert to work on it.
  4. But if the repair costs are exorbitant, purchase and install a new skylight that will give you a better experience
  5. Lastly, inspect and perform maintenance on your skylight regularly to extend its lifespan



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