When you are installing windows in your home for the first time, you don’t think about how they might break down. But, much like anything else you might install into your home, your windows can begin to show signs of wear and tear over time. This is particularly true for those windows that are subjected to extreme weather conditions and repeated use at higher levels than might be expected.

But when your window starts to leak, you may not even notice it immediately. While it’s true there could be some visual tell-tale signs of a leak due to discoloration from water damage, many leaks can be nearly impossible to diagnose because they manifest themselves as hairline cracks that could go unnoticed for months, even years.

So why do leaks happen and what can be done about the problem? The thing is, a window leak can come about from any number of causes. Yet no matter what the reason, the problem needs to be addressed quickly or you could risk spending a lot of money on your heating and cooling bills as well as repairing even minor water damage.

Here are the most common sources of window leaks and some of the ways you can prevent and even solve these problems if and when they do occur.


This may come as a surprise, but one of the most common causes of window leaks is lousy installation. A poor installation can lead to gaps between the frame and the house, leaving even a minuscule amount of space for air and water to seep in and out. If you let this persist too long, you will experience higher utility bills and you more than triple your risk of water leaking in during a storm.

When that happens, the water could soak into the wood, drywall, or even drip, and pool up under your carpets. All of these situations are bad and can cause your home to develop rot and mold.


This happens more often in much older homes as window frames can shift out of alignment over longer periods. It’s more common than you think and you may not even realize there’s a problem. But the natural shifting or settling of the frame can occur in the space of your home and when that happens, small cracks and fractures can develop.

This settling is so minor you may not even see any visible evidence of a crack or a fracture and you could be living with the issue for a long time. It might even require you to check if there is a leak with an infrared thermometer because without that you wouldn’t know it otherwise.


This is common among double and triple pane windows where multiple panes of glass are placed side by side inside the frame with insulating gas installed in between. When a seal inside the window has been compromised, you will tend to find condensation developing in between the panes. You can’t wipe it away because it’s inside the window.

The condensation will go away but if you don’t solve the issue, you will continue to see that condensation emerge on the glass more often. What’s more, your internal seal has allowed the insulating gas to leak out and that has made the windowless energy efficient. So while the leak isn’t allowing water to get in, it has allowed air to escape through the glass much easier and that may be why your energy costs have increased.


Finally, windows can start to break down due to age. It happens to the best of us. A window may not shut completely or a crank may start to fail, preventing you from opening or closing it all the way. When age is the culprit, there are a few steps you can take to solve the problem but you may need to replace the window sooner than later.

Preventing Leaks

First and foremost, the best way to prevent window leaks from occurring is to have your windows properly installed by a certified, reliable window installation contractor. Having them put in right the first time, will be your best bet to ensure that your energy-efficient windows remain that way for as long as you own them.

You can also select high-quality window products that are made from reliable components and water and stain-resistant materials.

Solving Leaks

It all depends on the reason for the leak. But in many cases, some nails, caulk, or weather-stripping may be all you need to seal up fractures and gaps in and around your windows. For more complicated problems due to broken internal seals and similar technical problems, you may need to have a professional come out to diagnose and repair the issue.

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