How to Repair a Window Seal (2023)

By Amanda Lutz

Nov 01, 2023
Young worker installing window in flat

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If you’re experiencing foggy windows, excess drafts, or fluctuating room temperatures, it might be time for window seal repair. Broken window seals allow outside temperatures to affect your home’s comfort levels and decrease your energy efficiency. Prolonged exposure to the outside elements will make your windows deteriorate, leading to mold and mildew.

We’ll review the basics of window seals, signs they could be damaged, and repair methods to help keep your window repair costs minimal.



What Are Window Seals?

Most homeowners used single-pane windows in the past. These windows provide minimum protection against external temperatures. Multiple panes of glass (also known as glazing) that use insulating inert gasses, such as krypton or argon, have better energy efficiency. These gasses block outside temperatures, helping maintain comfortable inside temperatures. Window seals lock in these gasses and prevent outside air from seeping in. You’ll find window sealants on multipane (or thermopane) windows, such as double- or triple-pane varieties.



Why Do Window Seals Break?

Insulated window panes, known as insulated glass units (IGU), break over time for several reasons. If you have window frames that require painting, IGUs could be affected when painters use heat guns to strip the paint. Pressure washing your insulated windows could cause broken seals. Window seals also deteriorate due to window panes expanding and contracting in the sunlight. Glass panes expand in the heat and return to their original shape overnight. Over time, this process wears down seals and could cause window pane cracks. The excess pressure from your home settling or high windows may also damage the window seals. 

Once the window seal is broken, you’ll lose the insulating barrier between your windows, causing external temperature to seep through the panes. The krypton or argon gas between the glass panes will leak through sealant cracks. Here are signs you have failed window seals:



4 Window Seal Repair Methods

Homeowners have several options for window seal repair. These methods vary based on your windows’ condition, the severity of damage, and the type of seal repair needed. We’ve listed the best window seal repair options below. 

  1. Use your warranty for IGU replacements
  2. Pay for IGU replacement
  3. Have your windows defogged
  4. Get a full window replacement

Use Your Warranty for IGU Replacements

If your IGUs need replacing, check your windows’ warranty coverage. Warranty coverage depends on your manufacturer and the windows’ quality. If you opted for low-cost replacement windows, your warranty coverage might only last a few years. High-quality window replacements could include a much longer warranty, up to 15 years or longer. High-end windows come with lifetime and double lifetime warranties that offer more comprehensive coverage for window glass and repairs. You could have little to no cost with a warranty replacement. 

IGU replacement is an excellent option if your current window frames are in good condition. If you’re still under warranty, contact the window manufacturer or installer and verify the warranty coverage. If covered, the window company will either send their own technician to complete the repair or ship the new IGUs. If the latter, you must find a local window installer or repair company to complete the work. 

Pay for IGU Replacement

If your warranty has expired, IGU replacement is still an affordable option. You should contact a professional contractor to complete the job. IGU replacements may be available for purchase from your windows manufacturer. If not, the window installer can provide suitable repair options. Here’s a general overview of how the installer completes an IGU replacement:

  1. The installer will remove the sash (or movable part of your window). 
  2. After removing any surrounding framework, the installer will take out the faulty IGU. This may involve removing any remaining sealant from around the window panes.
  3. The new panes are installed with new silicon sealant or sealant tape. 

IGU replacement is not recommended for inexperienced do-it-yourselfers (DIYers). You’ll need extensive knowledge to perform a proper installation. 

Have Your Windows Defogged

Homeowners could opt for defogging services to remove condensation from between the window panes. This process involves drilling a tiny hole in the glass pane’s exterior and pumping a condensation-drying chemical inside. The installer attaches a vacuum to remove as much air as possible. Finally, the vacuum hole is sealed again. 

Foggy window repairs only solve the condensation problem and serve as a temporary fix. Without proper resealing, your foggy windows will return. For a more permanent solution, have your window resealed adequately. This only works as a solution for glazed windows without inert gas insulation. If you have gas between the panes, you must replace the entire IGU.

Get a Full Window Replacement

We recommend full window replacement if your broken seals aren’t the only problem with your windows. Investing in new windows is the best option if you also have cracked panes, damaged frames, or old windows

Although this requires a larger investment, you’ll benefit from better energy efficiency and a style upgrade. Look for replacement windows with insulating gasses and efficient window frame materials. Triple-pane windows cost more than double-pane options but provide the highest energy efficiency and noise reduction.



Professional vs. DIY Window Seal Repair

Completing window seal repair is crucial to eliminate the chance of drafts, gas leaks, or frame damage. Most homeowners should not attempt complicated window repairs on their own. Although replacing IGUs is a simple process, mistakes could result in further window damage. Poor installation will also impact your home’s energy bills and comfort levels. Work with a professional window manufacturer or installer to ensure quality seal repair.

Professional installers back their work with warranties that cover future repairs. DIYers will miss out on those added protections. In addition, many window manufacturers have clauses in their warranties that void their coverage when professionals don’t complete projects.


Our Recommendation

Damaged seals impact your window’s overall visibility, efficiency, and protection. The right repair method depends on the seal damage’s extent and the state of your windows. If your windows are in excellent condition, you can keep your current frame and opt for IGU replacement. Check whether your window warranty is still active to minimize costs. Defogging can offer a temporary fix if you choose not to reseal your windows. If you have outdated windows with other external damage, your best option is replacing the entire window

If you need a window repair company for seal repairs, we suggest comparing at least three professionals to find the best deals.

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Window Seal Repair FAQ

Can you repair a window seal?

Yes, you can repair a window seal. You can replace the insulating glass unit or pay for defogging services for a more temporary fix. Full window replacement is recommended if your windows aren’t in good condition or are outdated.

How can you tell if window seals need to be repaired?

You can tell window seals need repair if you see any of the following signs:Damaged window framesDrafty windowsFog or condensation between window panesIncrease in energy costs Warped or distorted reflections

Why are window seals important?

Windows seals are important because they extend your window’s longevity by protecting them from outside temperatures and weather conditions. They help insulated windows maintain temperature control, ensuring your internal temperature remains comfortable. Glazed windows have insulating gas between the panes to regulate energy use, reducing energy costs over time.