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How To Fix a Cracked Window (2024 Guide)

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Cracked Window

Author Image Written by Jessica Wimmer Updated 04/29/2024

Even the slightest crack in a window can turn into a serious problem. You might be worried about handling the situation if you’re not a window expert, but most homeowners can solve this problem independently. 

In our step-by-step guide, we break down how to fix a cracked window in simple steps. We also recommend some of the best window replacement companies to help install a new window, if needed.

In the video below, This Old House general contractor Tom Silva helps a homeowner replace a cracked piece of glass.


How To Fix a Cracked Window

Glass repair requires a few simple tools you can find at any home improvement store. Here’s what you need:

Steps to follow

Before repairing the cracked window glass, we recommend analyzing the severity of the crack and identifying what caused it. Determine and address the cause, as you don’t want to fix your window just to have it crack again soon.

Also, examine the length and shape of the crack. It may be time to replace the window entirely if the crack is too severe or caused by old age. There may be a different type of glass better suited for your home. If that’s the case, contacting a professional window replacement company is the next best step to getting the right windows.

Here are the steps involved in fixing a cracked window.

Mix a drop or two of dish soap in a bowl of water. Dip a clean cotton rag into the soapy water and carefully clean the cracked part of the glass, removing any dirt and debris. Let the glass dry.

Next, make your two-part epoxy mixture in a well-ventilated room on a piece of cardboard or a paper plate. These mixtures are often a 50/50 blend of resin and hardener, but you should follow the directions on your specific product.

Use a toothpick to mix the epoxy for at least 20 seconds. The mixture thickens and hardens fast, so once it’s mixed, be ready to use it immediately. You should have five to 10 minutes of working time before the epoxy is too thick to seep into the break in the glass.

Apply the mixture to the cracked piece of glass with a putty knife. Do this gently to prevent further damage. Leave it to dry for about five minutes.

Scrape away excess epoxy with a razor blade or another sharp blade. Next, you can use a few drops of acetone glass cleaner and a clean rag to remove the epoxy raised above the crack. Let the now-repaired glass cure for around 24 hours.

Finally, spray your window with glass cleaner and polish it with a clean rag. Your window should now be as good as new.


Why Windows Crack

Windows crack for a variety of reasons. To prevent this from happening again, it’s important to find out how it happened. Some reasons are clear, such as a rock thrown by your lawnmower, but others are more difficult to pinpoint. Below are some of the most common reasons a window cracks.

Age

Like any other home product, windows have a life span. A window’s seal can break over time due to general wear and tear from routine use. Windows last around 15–30 years, but glass has a shorter lifespan of around 20 years. If your window’s age falls within this range, it may be more susceptible to pressure, temperature, and other environmental factors that cause cracks.

Hard Impacts

Hard impacts can cause cracks with a center that spread across the window glass in the form of a starburst. Impact cracks can be small or large based on the pressure of the impact.

Pressure Changes

Pressure cracks are not as common as other types of cracks, and they often appear out of nowhere. These cracks occur due to changes in the pressure system caused by weather. Often, window placement is the primary cause of pressure cracks. Pressure cracks curve and spread across the entire window.

Temperature Stress

If your home experiences extreme temperature fluctuations, your windows might experience temperature stress cracks. When there is a huge temperature difference between the inside and outside, stress cracks appear. These cracks start from one edge of the window and are often small at first. However, if you don’t take care of them, they can spread across the glass.

New Windows in Home
Window Replacement

Window replacement typically costs $300–$2,000 per window, depending on the window type.

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View looking out a casement window from the inside of a house that has turquoise interior walls
Window Repair

Window repair typically costs $177–$623, but it can vary based on the type of repair.

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Picture of a man cleaning a window with a yellow cloth
Window Cleaning Cost

Window cleaning typically costs $80–$430 for an entire home.

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Our Conclusion

If your window crack is small and caused by temperature stress or an impact, you can probably handle this repair with a do-it-yourself (DIY) approach. However, if the crack is large and you think it may be from pressure changes, it’s best to call a professional.

A windows expert can diagnose your problem quickly and provide access to some of the best windows brands if you require a complete replacement. Our tool below instantly connects you with window professionals who service your address. Check out our guide to cheap window replacement companies for budget-friendly options.

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FAQ About Fixing Cracked Windows

How do you cover up a cracked window?

You can cover up a cracked window with masking tape or mesh with super glue, but these solutions are only temporary fixes that halt the spread of the crack. They do not fix the crack. To completely remedy the issue, follow the steps in this guide or call a window technician. 

What is the easiest way to fix a broken window?

If your entire glass pane is broken, the easiest way to replace a broken window is to remove the glass using a putty knife, clean the window, and replace that specific section of glass. 

How do I know if my windows are good quality?

The quality of windows depends on how well they’re constructed. Most modern vinyl and aluminum windows are fusion-welded together, while low-quality windows may have smaller welds with caulk added to mask the crease at the sill.

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