two pane vinyl window with shutters on a vinyl siding house closeup

How to fix a cracked window in 5 easy steps

Jennifer Farrington Contributing Writer

Jennifer Farrington is a contributing writer at USA TODAY Homefront. She is a Florida native who has more than a decade of writing and editing experience. Jennifer has covered everything from real estate and insurance to personal finance and entertainment.

Updated Aug. 9, 2024

Key points

You can fix a cracked window by applying epoxy to the damaged area.
Without intervention, untreated cracks will spread over time until they are irreparable.
Severe window cracks can be temporarily repaired until a professional can assess the damage.

Windows come in a variety of shapes and sizes but have one thing in common — they are designed to be resilient against weather changes, pressure and impact. However, things don’t always work as intended, and your window glass may occasionally crack.

A sudden shift in temperature, a fly ball from a neighborhood baseball game, a falling tree limb or a hail storm can all lead to a cracked window, said Caleb Goodpaster, owner of Total Glassworks based in Austin, Texas.

The nature and severity of the break largely determine if it’s feasible to repair the cracked window glass yourself. If the glass crack is thick, deep or stretches across the window pane, you’ll need to contact a quality glass repair expert for help. The sooner you can have the damage repaired, the better — window replacement costs can be pricey, ranging from a few hundred to a few thousand dollars.

An image of cracked window glass — Fixing a cracked window can be a DIY project, but you may want to hire a professional who can correctly install glass. *James Kiefer, Homefront*

When window damage is minor — a chip or surface-level crack — you can repair it by applying a durable adhesive such as epoxy to the damaged area. Use our five-step guide below. But first, get prepared with the right tools for the job.

Gather tools and materials

You don’t need to be a do-it-yourself (DIY) enthusiast to apply a permanent fix to cracked window glass, but you will need some tools and materials commonly found at your local home improvement store. Here’s what you’ll need to gather:

Acetone
Clean dish rags
Epoxy
Gloves
Liquid dish soap
Masking tape
Mixing bowl
Putty knife
Razor blade
Toothpick (or something similar)

Epoxy is a class of polymers that provides a long-lasting bond between materials, including glass. Once cured, it dries clear and is chemical-resistant. Cured epoxy, with its resin-like appearance, is unlikely to pose any health risks, though it is recommended that you handle it with care.

How to fix a cracked window in 5 steps

Once you’ve gathered all the recommended tools and materials, it’s time to implement our 5-step glass repair guide. Here’s how to fix cracked glass without professional repair, or at least until professional assistance is available.

Step 1: Clean the window pane

Wipe the window clean using dish soap and a damp cloth to clearly see the area you’ll be working with. Remember to gently pass over the crack as it’s already vulnerable, and additional pressure could cause it to worsen. Softly wipe the window with a dry cloth.

Step 2: Mix the two-part epoxy

Epoxy has two parts: resin and a hardener. As soon as you combine the two, the resin begins hardening, and you have a limited time to mix and apply the product to your window.

To mix the epoxy, pour the two-part epoxy into your mixing bowl and carefully stir using a toothpick, dowel rod or similar object. Mix for about 20 seconds until fully blended. Most epoxy follows the same general mixing procedure, but you should follow the instructions of your specific product.

Remember to go outside or open the garage door and put on your gloves before mixing epoxy. The California Department of Health Services recommends handling the adhesive in a well-ventilated space as it can irritate your eyes, nose, throat and skin.

Step 3: Apply the epoxy to the crack

Take your putty knife and carefully apply the epoxy to the crack using a back-and-forth motion. For hairline cracks or those lacking a defined edge, smoothly spread the material across the fracture.

Don’t be afraid to exert a little bit of pressure, but use caution to avoid applying additional strain to the crack. Let the epoxy cure for at least five minutes or the recommended drying time outlined in the product’s instructions.

Step 4: Remove excess epoxy

Once the epoxy has dried, grab your putty knife. You’ll know it’s cured when the consistency changes from a gel to hard rubber. Scrape away the excess epoxy to achieve a smooth finish. Any remaining material can be wiped away with a dry cloth and some acetone. Allow the mended window to dry for 24 hours.

Step 5: Clean the window again

The final step in fixing a cracked window is to wipe the window clean with your preferred glass cleaner.

How can I cover a crack in my window?

Untreated cracked window glass will inevitably spread and can eventually reach a point beyond repair. It can jeopardize your home’s safety and disrupt the balance of insulating gas found within double-pane and triple-pane windows — found in nearly 80% of homes built in the 2000s — leading to increased energy expenses.

Because of this, it’s important to have a professional assess the situation as soon as possible. Until then, consider the following temporary fixes to contain the problem until a professional arrives.

Packing tape: If the crack is small, Goodpaster suggests applying packing tape to the crack “to prevent water penetration and glass from falling out of the opening.” Masking tape or duct tape can also be used.
Clear nail polish: Apply a few coats of clear nail polish until the crack is filled. Carefully wipe away any excess and allow each coat time to try.
Super glue: Apply the glue over the crack, ensuring complete coverage if the crack lacks depth or until it is completely filled.
Glass adhesive: Apply one thin layer of gel-like glue to the crack. Allow time to dry. Loctite is an example of one glass adhesive used to repair window cracks temporarily.
Plywood: Goodpaster recommends using plywood to cover large holes that expose you to external elements. Secure the plywood either by nailing or screwing it to the outdoor siding of the window to ensure interior protection.

Temporary window repairs are generally more cost-effective and easy, but they shouldn’t be relied on as a long-term solution. While these remedies can offer you a quick fix, particularly when your budget is tight or professional help is unavailable, they detract from your home’s aesthetic appeal and will likely require further attention.

As a window crack progresses, you’ll likely incur higher repair costs.

Why does window glass crack?

Windows can develop a variety of cracks, each resulting in distinct types of damage. Here are some of the most common window crack types:

Thermal stress cracks: These begin forming at the window’s edge perpendicular to the frame. They may snake out from there, typically changing direction at right angles. These fractures are triggered by a rapid fluctuation of temperature, causing the glass to expand or contract at varying rates.
Impact cracks: These cracks appear in a sunburst pattern with a clear center point. Debris kicked up by a mower or storm or a hard object thrown by a child are typical culprits for these.
Pressure cracks: These form when the atmospheric air pressure shifts substantially, which can happen during hurricanes, snow storms and the onset of cold weather. They often appear in a curved shape, like an hourglass.

Types of glass, such as tempered and annealed glass — may show cracks differently, too. “Annealed glass will have long cracks or small chips, while tempered glass tends to have small, intricate cracks throughout the entire piece of glass when it’s broken,” said Goodpaster.

What’s next?

Regularly monitoring your windows enables you to identify cracked glass early on and apply timely repairs before they worsen. A broken window may lead to air leakage and drafts, affecting indoor temperatures and potentially causing your electricity bills to spike.

If this isn’t the first time you’ve experienced a stress crack, your windows may need to be replaced with thicker and more durable materials specifically designed to withstand heightened temperature fluctuations. Be aware of outdoor alterations that could cause significant temperature shifts, such as the removal of a shade tree, when determining whether window replacement is necessary.

Window repair professionals can offer expert advice on the best window brands to select from, allowing you to replace your windows with top-notch, energy-efficient materials tailored to your living conditions and environment.

Editorial note: The name “Homefront” refers to the alliance between USA TODAY and Home Solutions that publishes review, comparison, and informational articles designed to help USA TODAY readers make smarter purchasing and investment decisions about their home. Under the alliance, Homefront provides and publishes research and articles about home service and home improvement topics.

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