Window Seal Repair: Identifying & Fixing Broken Window Seals [2022 Guide]

In this guide, you’ll learn:

  • What are window seals, and how do you repair them?
  • Are broken window seals a severe problem?
  • How do you tell if your window seal is broken? 
  • Can you repair a broken window seal yourself?
  • And more
Ecowatch Author Dan Simms

By Dan Simms

Updated 8/3/2022

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If you think you have a broken window seal and you’re wondering how to tell and get the issue fixed, you’re in the right place.

Your windows are your home’s first line of defense against outdoor temperatures and the elements, so they’re under constant pressure to perform and keep your living space comfortable. Unfortunately, that means windows can easily get damaged, necessitating sometimes expensive repairs. If you think the seal around one of your window panes might be broken, you’re probably wondering how to confirm that it is and, more importantly, how to fix it.

In this guide, we’ll discuss what exactly a window seal is, how to identify if one in your home is broken, the average cost of professional window seal repair, and more.

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Jump To: Window Seals: What Are They and How Do You Repair Them? | Why Do Window Seals Break? | Are Broken Window Seals a Problem? | How Do You Tell If a Window Seal is Broken? | Can Broken Window Seals Be Repaired? | DIY vs. Hiring a Professional | How to Prevent Window Seals From Breaking

Window Seals: What Are They and How Do You Repair Them?

A window seal is a seal around your glass panes that prevents air and water from seeping through your windows. Most modern windows are double-pane windows, which means there are two panes of glass with a sealed void between them that is filled with gas. The seal is created around each pane of the entire insulated window with a rubber sealant that’s usually made from silicone or polyurethane.

If at any point the seal around the pane cracks or is damaged, the gas trapped between the panes escapes, and you’re left with a broken window seal. When this happens, double- or triple-pane windows lose much of their insulative capability, and the heat transfer between your living space and the outside becomes more rapid.

Repairing a window seal involves removing the pane with the damage, cleaning the area, reinstalling the pane, filling the void once again with gas, and then resealing around the pane.


Why Do Window Seals Break?

The sealant around your window panes is usually either silicone or polyurethane, which can stretch and shrink to some degree with changes in temperature and humidity. During the day, when your windows are in direct sunlight, the glass expands slightly, only to shrink when the temperature dips at night. 

Window sealant is meant to stand up to some movement, but this constant cycle of expanding and contracting will eventually cause the seal to crack. This is especially an issue with aging windows, as the sealant can dry out over time and lose elasticity.

Are Broken Window Seals a Problem?

Broken window seals are an issue, but they aren’t as much of an emergency as a broken window pane. Still, if you recognize that your window seal is broken, it’s best to get a remedy in place right away.

The seal around your double-pane and triple-pane windows are a big part of what determines your window’s energy efficiency. If the seal breaks, the outside air can enter the space where the insulative gas used to be, and you’re left with what is essentially a single-pane window. Your window loses much of its insulative value, meaning your energy bills will likely increase a bit, your heating and cooling system will work harder and be at greater risk of issues, and your living space could become less comfortable.

Multiple-pane windows also prevent condensation from forming on your window glass, so a broken seal can leave condensation between the panes. Not only is this frustrating because it blocks your view through the window, but it can also increase the likelihood of condensation on the inside of your window. If the condensation accumulates enough, it can drip onto your window frame or flooring, potentially causing water damage.

How Do You Tell If a Window Seal is Broken?

window seal repair tip

Identifying a broken window seal is something every homeowner should be able to do, but few know how. There are three things to look out for: condensation between your window panes, hot or cold glass inside your home, and a distorted view through the window.

Condensation forming between your window panes is one of the clearest signs of a broken window seal. When the seal around the pane is compromised, moisture will enter the void and build up between areas of disparate temperatures — in this case, the inside of your home and the outside air. If you see condensation on your windows that you can’t wipe off from inside or outside, the chances are good that your window seal is broken.

Another thing to look for is unusually hot or cold glass inside your home. When your window seal is broken, your inner pane will be the only line of defense against outdoor temperatures. As such, the glass will feel hotter than normal in the summer and colder than normal in the winter.

Finally, your glass panes can bow slightly once the seal is broken and the vacuum-sealed gas is released. If this happens, you might notice that the view through your window is a bit distorted. Distortion can occur even if you don’t notice the other two symptoms.


Can Broken Window Seals Be Repaired?

Yes, absolutely. Just like window seals can be created during the manufacturing process, they can also be repaired once they are broken. The process is relatively straightforward when done by a professional.

If you hire a window repair company, the technician will remove the damaged pane, reintroduce argon gas or krypton gas into the void between the panes and recreate the seal around the window panes. The work might also involve reassembling the window frame if it was taken apart for the seal repair.

What Does Window Seal Repair Cost?

On average, hiring a professional window repair company to fix a broken window seal will cost around $140. Most homeowners pay between $100 and $200 for this service, depending on the size of the pane, the location of the window, and the type of window you need to be repaired.

However, a premature seal failure is often covered under a warranty. If you’re experiencing a broken seal on a new window, the repair might not cost you anything.

Fixing Broken Window Seals: Repair or Replace?

If you have a broken window seal and you’ll be paying an average of $140 to repair it, you might be wondering if it’s worth it just to replace the entire window. There are a few things to consider before you decide.

First, the average cost of replacing a double-pane window is around $450, while the typical cost of repairing a broken window seal is much cheaper at around $140. However, if your window is older anyway — approaching or above 20 years old — then window replacement probably makes more sense. Windows gradually degrade and become less energy-efficient over time, so you’re better off replacing old windows than sinking money into repairs for them.

You should also consider the overall quality of your window. If your window has an aluminum frame that isn’t particularly energy-efficient, you might consider replacing the window with one that has more insulative frame material. Some more-efficient options include vinyl, composite, and fiberglass.

If your window isn’t particularly old and is already equipped with high-quality frame material, repairing the broken window seal is a more cost-effective option.

DIY vs. Hiring a Professional for Broken Window Seal Repair

Although the cost of having a professional repair your broken window seal isn’t that high, many homeowners wonder if a DIY window seal repair is possible. Unfortunately, it’s not practical to reseal your own window panes, as the job requires special equipment and insulative gas. If you’re looking strictly for a window seal repair, you should hire a professional to do the work for you.

With that being said, it is possible to replace window panes with broken seals yourself. You can purchase new insulated glass units (IGUs) from window manufacturers, and you can install them yourself by disassembling your window’s body panel, removing the old glass, inserting the new IGU, and reassembling the body panel. Here’s a quick overview:

In most cases, the money you’ll save on labor costs by doing a DIY window repair is not worth the time it will take and the risk of making a mistake. As such, we recommend hiring a professional window repair technician if you need to repair a broken window seal.

How to Prevent Window Seals From Breaking

Broken window seals can be a nuisance, and they can cost you a significant amount of money in repairs and energy costs if the problem is recurring. Luckily, there are a few things you can do to prevent your window seals from breaking. Keep in mind, though, that window seals will eventually break in any case, so the tips below are just to make the issue pop up less frequently.

First, you can limit broken window seals and other window damages by having a professional — ideally the window manufacturer — install your window for you. Even slight issues with window installation can leave your window at risk of bending, warping, and bowing, and all of these actions can put added pressure on the window seal.

Second, you can avoid power washing your windows. Windows need cleaning occasionally, but using a power washer with high pressure can damage the window seals around your glass panes.

Third, some resources recommend using heat guns to remove paint from window frames. While this will make removing paint a quick process, the heat can cause the window sealant to expand, putting it at risk of cracking when it cools.

Finally, you can check the seals around your window panes every year or so and make minor repairs to the sealant as needed to prevent major damage. Repairing slight cracks or signs of tearing early can prevent the seal from breaking entirely, which means you’ll save money on the repair and also maintain better home energy efficiency year-round.


FAQ: Window Seal Repair

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Dan Simms

Dan Simms is an experienced writer with a passion for renewable energy. As a solar and EV advocate, much of his work has focused on the potential of solar power and deregulated energy, but he also writes on related topics, like real estate and economics. In his free time — when he's not checking his own home's solar production — he enjoys outdoor activities like hiking, mountain biking, skiing and rock climbing.