There are a number of things that can go wrong with your window that necessitate repair, but one of the most urgent issues you should fix immediately is a broken window seal. While it’s possible to repair this type of damage as a do-it-yourself repair, many homeowners don’t know how to do it, let alone determine if a broken seal is the real issue at hand.

In this guide, we’ll be discussing how to tell if you have a failed seal, some reasons why window seals break, and how to fix the problem once you identify it. We’ll also explain if a DIY or professional repair is better and how to prevent window seals from breaking in the future.

    How to Tell if Your Double-Pane Window Seal Is Broken

    Before we dive into how to fix a broken window seal, you should be able to identify that a broken seal is really the issue you have. There are a few things you can look for to help you confirm that this is the problem you’re experiencing. We’ll discuss the signs of a broken window seal in the sections below.

    Condensation Between the Panes

    The most obvious sign of a broken window seal is condensation on your window that you can’t wipe off from the inside or outside. A foggy window is a clear sign that condensation is forming between the panes of glass on a double-pane window or a triple-pane window. That means the insulative inert gas — usually argon gas or krypton gas — that was vacuum sealed between the panes has escaped, and the void is open to outside air and moisture.

    If you have a double-pane window moisture problem, check out our double-pane window moisture removal guide.

    A Drop in Your Home’s Energy Efficiency

    If you pay attention to your electric bills and notice that your heating and cooling costs increase unexpectedly, that’s a good sign that you have a broken window seal on your hands. Having multiple panes with insulative gas sandwiched between them helps reduce the transfer of heat between the outdoor air and your living space. A broken

    seal will not provide the same insulation, causing a dip in efficiency.

    Noticeable Drafts

    For similar reasons, if you notice drafts of cold air coming in through your windows during the colder months, it could be a sign of a broken window seal. Drafts can also result from damage to the window frame or the moveable sashes in your window, so you should look for other signs of a broken seal to confirm that’s the issue.

    Issues With Your Window Frame

    Finally, if you notice damage to your window frame or you find that your window is hard to open or close, there’s a possibility the frame around your panes of glass has shifted. Since your frame can flex a bit and glass cannot, it’s possible that shifting or even expansion can cause the seal around your glass to break. Finding frame issues doesn’t automatically mean a broken window seal, so confirm with other signs if possible.

    What Causes a Window Seal to Break?

    The most common cause of a broken window seal is just the natural expansion and contraction of the window materials. Since your windows are exposed to the elements, they’ll naturally see extreme changes in temperature and humidity. As these changes occur, the glass can expand and contract slightly, putting pressure on the seal. As this occurs over and over again, the seal can eventually fail. This typically only happens after years of exposure.

    Since the window seal around your glass is somewhat fragile, the natural shifting of the other window components can also cause the seal to break. For example, natural house settling can cause the framing around the window to shift, warp, and bow slightly over time. Even small movements can cause the window seal to be damaged.

    Finally, on a more extreme level, foundation issues can cause window seal damage. Since your entire home relies on your foundation for stability, cracks, water intrusion, and bowing foundation walls can all cause the framing above the area to shift unnaturally. Just like with natural settling, this can put excess strain on your windows and eventually lead to a broken window seal.

    The Best Ways to Repair a Broken Window Seal

    If you identify a broken window seal in your home, there are a few different things you can do to rectify the issue. We’ll discuss each of your options in the sections below.

    Replace the IGU

    One of the simplest and least intrusive repairs is to replace the insulated glass unit (IGU). This is a relatively straightforward DIY home improvement project, but it’s best left to experienced DIYers.

    You can do this by removing the sash from your window, popping off the window bead used to hold the insulated window glass in place, using a putty knife to break the silicon seal between the sash and the glass, and then removing the glass. You can then remove all of the excess sealants from the frame and install your new IGU with silicon sealant tape and clear silicon.

    Read also: Windows Insulation Guide

    Get a Full Window Replacement

    A more expensive and involved option is to replace the entire window. This is best left to a professional, as it will involve removing the old window, ensuring the framing behind it is free from mold, water damage, and excess shifting, and then fitting and installing a new window.

    This is a great option if you know your window with the broken seal is old or if you’ve found that your home’s energy efficiency has dropped recently. It’s also an opportunity to upgrade your frame materials to something more efficient, like fiberglass.

    Make a Claim with Your Window Warranty

    If you’re experiencing an issue with a window you installed recently, it might still be under warranty. If that’s the case, your most affordable option is to make a warranty claim. This should cost you nothing, provided the warranty covers the damage you’ve experienced. Your original installer or the window manufacturer should repair or replace the damaged unit for free.

    Have it Re-Sealed

    Finally, you can have the window resealed, which can often be done by a professional in an hour or two. This process involves defogging the window — which just means removing all of the moisture from between the panes — refilling the void with insulative argon or krypton gas, and then resealing around the glass unit.

    This process should not be attempted as a DIY project, as it requires special tools to remove moisture, fill the void with gas, and reseal without letting the gas escape.

    In addition to learning how to fix broken window seals, you might also want to know how to repair your window panes when they are damaged. We suggest you watch our video for a complete tutorial on fixing broken window panes.

    DIY vs. Professional Window Seal Repair

    Any homeowner who has some experience with DIY home repairs will probably be tempted to fix their broken window seal themselves. While it is possible, it’s generally not recommended.

    The seal around your window panes is essential for keeping your home energy-efficient, so any mistakes you make could lead to higher heating and cooling bills, an uncomfortable living space, and resorting to a professional repair in the end anyway. Additionally, failure to reinstate the seal properly can expose your home to water intrusion, which can lead to severe damage, mold growth, and lower indoor air quality.

    Additionally, a professional window repair company will be able to identify if a broken window seal is your real issue, and they’ll be able to diagnose additional issues if there are any.

    All in all, we think it’s best to leave foggy window repair to a professional. Check out the window contractors below to get help with window repair.

    Cost of a Window Seal Repair

    If you choose to repair your broken window seal yourself, you could spend as little as $20 in supplies and another $20 or so on a new insulated glass unit — keep in mind that larger units will naturally cost more. That’s a total of just $40.

    If you have a professional come in and reseal the window, you could pay as little as $50. Having the window technician replace the insulated glass unit could cost you between $75 and $150.

    If you choose to replace the entire window, you’re looking at an average cost of around $600. However, the price can vary based on the size and type of window. Your total could fall anywhere between $150 and prices well over $1,000.

    How to Keep Your Window Seal From Breaking

    Of course, it’s always better to avoid an issue in your home than to wait for one to pop up and then fix it. Luckily, there are a few things you can do to avoid a broken window seal.

    The first thing, if you have the option, is to choose a high-quality window from the get-go. Installing a durable window from a reputable brand like Andersen, Pella, or Marvin will always cost a bit more, but it’s usually worth it because you can avoid issues for years or even decades after window installation.

    To avoid a window seal issue on a window you didn’t have installed yourself, you can carry out proper window maintenance. One of the most crucial things to do is re-caulk around where the glass meets your frame on the outside of the window once per year. This will help limit how much temperature and moisture changes affect the seal inside.

    Finally, you can inspect your windows for damage or difficulty opening and closing about once a year. Finding symptoms of shifting window frames can help identify problems before they become severe enough to lead to a broken seal. You can then address the underlying issue rather than wait for the seal to break.

    Final Verdict: Is a Window Seal Repair Worth It?

    Your window seals are responsible for keeping the elements outside where they belong and helping to maintain a comfortable indoor temperature. Not only is repairing window seal failure essential for keeping your family comfortable and safe, but it also helps maintain the energy efficiency of your home. The money you’d spend on repairing your seal will likely be recuperated on your energy bills.

    The bottom line is that repairing a broken window seal is absolutely worthwhile. Even paying a professional to carry out the window repair service for you is recommended over letting the issue worsen, which can lead to reduced home efficiency and expensive water damage in your living area.

    Frequently Asked Questions

    Do broken window seals need to be repaired?

    Technically, you could get away without repairing a broken window seal, but it’s not recommended. A broken seal means you’re leaving your home exposed to the elements, so your energy efficiency will drop, your utility bills will increase, and your living space will become less comfortable. It’s always worthwhile to repair a broken window seal as soon as you identify the issue, especially if you live in an area that experiences extreme temperatures.

    What are the benefits of repairing a window seal?

    Most importantly, repairing a window seal will improve your home’s energy efficiency. Your heating and cooling equipment won’t have to work as hard to maintain your desired interior temperature, which means your equipment will last longer without expensive repairs or glass replacement, and your energy bills will naturally be lower.

    Repairing broken window seals also means the outdoor air will stay outside where it belongs. Window seals that are left broken will lead to drafts in your home that make your living area colder in the winter and uncomfortably hot in the summer.

    Finally, broken window seals can lead to condensation between the panes that cannot be wiped away. Repairing your seal can mean restoring a clear window, giving you unobstructed views of the outdoors.

    Is a broken window seal a big deal?

    Yes, absolutely. Broken window seals decrease your home’s energy efficiency and can drive up heating and cooling costs. They can also be indicative of more severe issues, like shifting frames or frame damage. If that’s the case, they can be a sign that your home is exposed to water from the outside, which can cause severe damage and mold growth. Shifting frames can also sometimes help you identify structural damage in your home.

    Does homeowners insurance cover broken window seals?

    In most cases, no, homeowners insurance won’t cover broken window seals. This is largely because the underlying cause of a broken seal is considered a lack of proper maintenance. Even if your insurance did cover it, it’s best to avoid small claims like window repair, as these can drive up your monthly premiums.

    How long do window seals last?

    With proper maintenance, a window seal on a high-quality window can last 20 years or more.

    Editorial Contributors
    avatar for Dan Simms

    Dan Simms


    Dan Simms worked in real estate management for five years before using his experience to help property owners maintain their own homes. He got his master’s degree in English Literature and Creative Writing, and he now enjoys sharing his knowledge about homeownership and DIY projects with others on Today’s Homeowner. When he’s not writing, he’s usually outdoors with his wife and his dog, enjoying mountain biking, skiing, and hiking.

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    Lora Novak

    Senior Editor

    Lora Novak meticulously proofreads and edits all commercial content for Today’s Homeowner to guarantee that it contains the most up-to-date information. Lora brings over 12 years of writing, editing, and digital marketing expertise. She’s worked on thousands of articles related to heating, air conditioning, ventilation, roofing, plumbing, lawn/garden, pest control, insurance, and other general homeownership topics.

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