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Why is there moisture between my double paned windows?

Double-paned windows are a popular choice for homeowners due to their superior insulation properties. However, these windows can sometimes develop moisture between the panes, which can be both unsightly and a sign of underlying issues. Understanding the causes, signs, and solutions for moisture build-up can help you maintain the efficiency and appearance of your double-paned windows.

Key Takeaways

  • Moisture between double-paned windows is often caused by a broken seal, allowing air and humidity to enter the space between the panes.
  • Temperature differences between the inside and outside of your home can lead to condensation forming between the panes.
  • Visible signs of a failed window seal include condensation, fogging, cloudiness, and pooling water at the bottom of the window.
  • Preventive measures such as maintaining window seals, controlling indoor humidity, and regular inspections can help avoid moisture build-up.
  • If moisture issues arise, options include replacing the window seals, professional glass replacement, or temporary DIY solutions.

Understanding the Causes of Moisture Between Double-Paned Windows

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Temperature Differences and Condensation

When there is a significant temperature difference between the inside and outside of your home, condensation can form on the windows. This happens because the warm, moist air inside your home comes into contact with the cooler surface of the window, causing the moisture to condense. Over time, this can lead to moisture build-up between the panes.

Seal Failure and Moisture Intrusion

Double-paned windows are sealed to maximize insulation. If that seal breaks, cracks, or otherwise fails, moisture enters between the panes. Depending on the humidity and temperature outside, it may fog, pool, or collect at the bottom, or it may show up as condensation. Regardless, once that seal has been broken, most of the window’s ability to insulate is gone. This is especially true if your double-paned windows contained argon gas, like most double pane windows these days do.

Impact of Humidity Levels

High indoor humidity levels can exacerbate moisture problems in double-paned windows. When the air inside your home is humid, it increases the likelihood of condensation forming between the panes. Using dehumidifiers and ensuring proper ventilation can help manage indoor humidity levels and reduce the risk of moisture build-up.

Signs That Your Double-Paned Window Seal Has Failed

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Visible Condensation

When the seal of a double-paned window fails, one of the first signs is visible condensation between the panes. This occurs because the airtight seal that prevents moisture from entering the space between the panes has been compromised. As a result, moisture from the air seeps in and condenses on the cooler surface of the glass. This condensation can appear as droplets or a misty layer, and it is a clear indication that the window’s insulating properties have been significantly reduced.

Fogging and Cloudiness

Another common sign of seal failure is fogging or cloudiness between the panes. This happens when moisture accumulates and remains trapped between the glass layers, creating a foggy or cloudy appearance. This not only obstructs the view but also indicates that the window is no longer effectively insulating your home. Over time, this fogging can become more pronounced, making it difficult to see through the window.

Pooling Water at the Bottom

In some cases, you may notice pooling water at the bottom of the window. This occurs when the moisture that has entered between the panes collects and settles at the lowest point. This is a more severe sign of seal failure and can lead to further damage if not addressed promptly. The presence of pooling water suggests that the seal has been broken for an extended period, allowing significant moisture intrusion.

If you observe any of these signs, it is crucial to address the issue promptly to prevent further damage and maintain the energy efficiency of your windows.

Preventing Moisture Build-Up in Double-Paned Windows

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Maintaining Window Seals

Regular maintenance of window seals is crucial to prevent moisture build-up. Inspect the seals periodically for any signs of wear and tear, and replace them if necessary. Using a dehumidifying product specifically designed for double-pane windows can also help in maintaining the integrity of the seals.

Controlling Indoor Humidity

Controlling the indoor humidity levels is essential to prevent condensation between the panes. Use dehumidifiers, especially in high-humidity areas like bathrooms and kitchens. Additionally, ensure proper ventilation to allow moisture to escape.

Regular Inspections

Conduct regular inspections of your double-paned windows to catch any potential issues early. Look for visible condensation, fogging, or pooling water at the bottom of the window. Early detection can save you from more extensive repairs down the line.

Regular maintenance and timely inspections are key to preventing moisture build-up in double-paned windows. By taking proactive steps, you can extend the life of your windows and maintain their insulating properties.

How to Fix Moisture Issues in Double-Paned Windows

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Replacing the Window Seals

When dealing with moisture between double-paned windows, one of the most effective solutions is to replace the window seals. Failed seals allow moisture to seep in, and no amount of drying or ventilation will fix this issue. Replacing the seals can restore the window’s insulating properties and prevent further moisture intrusion.

Professional Glass Replacement

If the seals are beyond repair, professional glass replacement might be necessary. This involves replacing just the glass, not the entire window, which can be a cost-effective solution. Contacting a local glazing expert can ensure the job is done correctly and efficiently.

Temporary DIY Solutions

For a temporary fix, you can use dehumidifying products specifically designed for double-pane windows. Products like WD-40 Original Spray can absorb moisture from between the panes. Additionally, using a towel to act as a barrier can help prevent warm air from coming into contact with the cold glass, reducing condensation buildup.

In some cases, temporary solutions can provide short-term relief, but they are not a substitute for professional repairs or replacements.

The Role of Argon Gas in Double-Paned Windows

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Insulation Benefits of Argon Gas

Argon gas is commonly used in double-paned windows due to its excellent insulation properties. Argon is a non-toxic, inert gas that is denser than air, which helps to reduce heat transfer between the panes of glass. This results in better thermal performance and energy efficiency for your home. The use of argon gas can significantly lower heating and cooling costs by minimizing heat loss in the winter and heat gain in the summer.

Effects of Argon Gas Leakage

Over time, the seals of double-paned windows can degrade, leading to argon gas leakage. When this happens, the window’s insulation properties are compromised, resulting in higher energy bills and reduced comfort. Signs of argon gas leakage include condensation between the panes and a noticeable drop in the window’s insulating performance. It’s important to address seal failures promptly to maintain the efficiency of your windows.

Maintaining Argon Gas Levels

To ensure the longevity and effectiveness of argon-filled double-paned windows, regular maintenance is crucial. This includes periodic inspections to check for seal integrity and any signs of gas leakage. If a seal failure is detected, it may be necessary to replace the window or have a professional reseal it to restore its insulating properties. Maintaining proper argon gas levels helps in preserving the energy efficiency and comfort of your home.

Regular maintenance and prompt attention to seal failures can help maintain the energy efficiency and comfort provided by argon-filled double-paned windows.

When to Consider Replacing Your Double-Paned Windows

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Assessing the Extent of Damage

When evaluating whether to replace your double-paned windows, it’s crucial to assess the extent of the damage. Visible condensation between the panes is a clear indicator that the seal has failed. Additionally, if you notice fogging or cloudiness that doesn’t go away, it might be time to consider a replacement. Pooling water at the bottom of the window frame is another sign that the integrity of the window has been compromised.

Cost-Benefit Analysis

While replacing double-paned windows can be expensive, it may provide better value for money in the long term. Consider the energy efficiency benefits and the potential savings on your energy bills. If your windows are under guarantee and you are experiencing issues within the first 10 years, check to see if you can get a replacement under warranty.

Choosing the Right Replacement Options

When selecting replacement windows, it’s important to choose high-quality options that will last. Double-paned windows typically last around 15-20 years, but this can be impacted by factors such as thermal pumping and wear and tear. Custom-made windows can ensure a perfect fit and provide the best performance for your home.

Simply put, if you start to get moisture in your windows—be it in the form of condensation or another form—it’s time to look into replacement windows.

Professional Help for Double-Paned Window Issues

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When dealing with moisture issues in double-paned windows, finding a qualified glazing expert is crucial. These professionals have the expertise to diagnose and address problems such as condensation and seal failures. Look for experts with good reviews and proper certifications to ensure quality service.

During a professional inspection, the glazing expert will check for any damage, mould, or mildew growth. They will also assess the condition of the window seals and the presence of moisture between the panes. This thorough inspection helps in identifying the root cause of the problem and determining the best course of action.

The cost of professional repairs can vary depending on the extent of the damage and the type of repair needed. Generally, resealing processes are less expensive than full window replacements. It’s advisable to get multiple quotes to compare prices and services offered by different professionals.

If your double glazed windows still have condensation or moisture between them, then the professional may be able to carry out a resealing process which could help to prevent the issue from occurring in future.

If you’re experiencing issues with your double-paned windows, it’s time to seek professional help. Our expert team at Edinburgh Window Cleaners is fully licensed, insured, and ready to restore your windows to their pristine condition. Don’t let foggy or broken windows ruin your view—visit our website today to schedule an appointment and see the difference we can make!


Moisture between double-paned windows is a common issue that can significantly impact the insulation and efficiency of your windows. This problem typically arises when the seal between the panes fails, allowing air and moisture to enter. The resulting condensation is not just an aesthetic concern but also a sign that your window’s insulating properties have been compromised. Addressing this issue promptly by replacing the seals or the glass itself is crucial to maintaining the energy efficiency of your home. By understanding the causes and solutions for condensation between double-paned windows, homeowners can take proactive steps to ensure their windows remain in optimal condition.

Frequently Asked Questions

How do you stop condensation between double-pane windows?

To stop condensation between double-pane windows, you need to address the broken seal that is allowing moisture to enter. This typically involves replacing the window seals or the entire window unit. Professional help is recommended for an effective solution.

What can I do about condensation between different panes on double glazing?

Condensation between panes on double glazing indicates a seal failure. You can either replace the seals or the glass unit itself. Consulting a professional glazing expert can provide you with the best course of action.

What causes condensation and moisture between window panes?

Condensation and moisture between window panes are caused by the temperature difference between the inside and outside air. When warm, humid air meets the cooler surface of the window, it condenses and forms droplets.

How to get rid of condensation between window panes?

To get rid of condensation between window panes, you will need to replace the seals or the entire window. This is usually a sign that the seal has failed, allowing air and moisture to enter between the panes.

How to remove the condensation between the window panes?

Removing condensation between window panes involves wiping away any visible moisture and addressing the seal failure. This may include replacing the seal or consulting a professional for glass replacement.

What does condensation in the gap between double glazing mean?

Condensation in the gap between double glazing usually means the sealant around the panes is deteriorating. Over time, the sealant can degrade and crack, allowing air and moisture to enter and create condensation.