How Do You Know If A Sealed Window Has Failed?

These days, most homes have windows that incorporate double and triple panes. Simply put, that means the windows incorporate multiple panes of glass that are housed within a frame that been sealed air-tight. These types of windows are designed for increased energy-efficiency and lower heating and cooling costs.

But when the seals on your window begin to fail, you’ll be throwing money right out the window as your costly climate-controlled indoor air can begin to seep out. Trouble is, you may not even know it’s happening and that can get pretty expensive before too long.

Failed seals aren’t always immediately noticeable. Depending on the severity of failure, your window may or may not actively demonstrate any compromised effect at first. Some windows may alert you almost immediately. But either way, your window is no longer weather-proof and that’s a problem you need to address fast.

The Factors of Failure

Look around. The windows in your home are most likely composed of multiple panes. That means they’ve been equipped with seals that are designed to make your windows act as fortified barriers between the inside of your home and the outside world.

But like any other part of your home, especially those that are considerably older, the windows can start to display substantial wear and tear. The only trouble is that windows are usually much more delicate than other components of the dwelling.

Windows have delicate glass and they come with a variety of moving parts that can become compromised if they are handled roughly. How many times have you absent-mindedly slammed a window shut. Nothing breaks at the time, but repeated actions such as this can begin to take a toll on the frame and the seals.

When a seal finally fails, it usually happens in the Insulated Glass Unit or IGU for short. This is the foundation of the window apparatus and when it fails, this can occur immediately or through a slow leak that can get worse as time goes by.

But there are other factors that can contribute to a failed seal. Homes that are located in climates with extreme shifts in temperature are subject to greater potential for compromise. That’s because temperature has a direct effect on the expansion and contraction of glass which can have a direct impact on the seal itself.

The window manufacturers account for these adjustments with glazing beads that shift with the changes in glass to help protect the seal and keep it from breaking. These windows also incorporate low-emissivity coatings which are used to help reflect heat. This also takes some of the pressure off the seals. Finally, argon gas is introduced in between the panes as a means of insulation.

Diagnosing Failed Seals

The immediate indicator that a seal has failed is pretty easy to spot. You will see that the glass in your window has fogged over or become visibly streaky from the inside. This occurs as a result of coating that has become oxidized due to a bad seal.

Now just because your window is foggy does not automatically mean your window seal is no longer effective. You will need to take a few steps towards diagnosing the problem to tell for sure if you’re dealing with this kind of problem. Here is what you want to do:


Give your window a thorough cleaning in and out. This is critical because you need to be able to see into the window without any impediments, So take extra care to wipe away any grime or other distractions so you are able to see if there is actual moisture inside of the window.

Checking for Moisture

Now that the window is spotless, take a good long look to see if the appearance has changed. Look closely into the window and see if you can detect any evidence of moisture. This can be seen in the form of a fog or a haze that exists in between the panes.

If you see anything like this, your seal has failed.

Distortion Effects

Another indication of a failed seal is by diagnosing the position of the glass panes in the IGU. If the seal has broken, the argon gas will escape, resulting in a visible warping of the glass. You can see this by checking the reflection in the glass, it will be significantly distorted.

If you see this, your seal has failed.

After you’ve checked your windows for failed seals, call Richmond Window Corp. to see if your windows can be repaired or if a replacement is needed.


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