Why do windows lose their seal?

Are you frustrated with condensation forming between the glass panes of your windows? Have you noticed that your windows are no longer providing the insulation and energy efficiency they once did? If so, you’re not alone. Many homeowners experience the same problem: windows losing their seal. But what exactly causes this to happen?

In this article, we will explore the common reasons why windows lose their seal and what you can do to prevent it from happening. From age and wear to poor installation and manufacturing defects, there are several factors that can contribute to a window’s seal failure.

Understanding these reasons can help you make informed decisions when it comes to repairing or replacing your windows. Join us as we uncover the mysteries behind this frustrating issue and find out how you can restore the functionality and appearance of your windows.


Understanding window seals

Windows seals are an essential component of double-glazed or insulated windows. They are responsible for creating an airtight barrier between the glass panes, preventing air and moisture from entering the space between them. The seal also helps to maintain the insulating properties of the window, preventing heat transfer and ensuring energy efficiency. Understanding the structure of window seals is crucial in identifying the reasons behind their failure.

Most modern windows have two types of seals: primary and secondary seals. The primary seal is a gasket or sealant that is applied between the glass and the frame, creating an airtight bond. The secondary seal, also known as the structural seal, is typically made of silicone or other flexible materials and is applied to the edges of the glass, providing additional protection against air and moisture infiltration. When both seals are intact and functioning correctly, the window remains sealed, ensuring optimal performance.

Common causes of window seal failure

  1. Age and wear: Over time, the materials used in window seals can deteriorate due to exposure to the elements, temperature fluctuations, and general wear and tear. As the seals age, they become less flexible and more prone to failure. This can result in cracks, gaps, and loss of elasticity, compromising the integrity of the window seal.
  2. Poor installation: Improper installation of windows can lead to seal failure. If you don’t install the seals correctly or leave gaps between the glass and the frame, air and moisture might get in, which can make the seals fail early. It’s crucial to have qualified professionals install windows and follow industry best practices to stop seal failure.
  3. Manufacturing defects: Sometimes, manufacturing defects can cause window seal failure. If the manufacturers didn’t apply the seals correctly or used low-quality materials, the seals might fail early. This can result in condensation, reduced insulation, and decreased energy efficiency.

Signs of a failed window seal

Detecting a failed window seal is relatively straightforward. Here are some common signs to look out for:

  1. Condensation: One of the most noticeable signs of a failed window seal is the appearance of condensation or fog between the glass panes. This occurs when the airtight seal is compromised, allowing air and moisture to enter the space between the panes. The condensation can obstruct the view and indicate a seal failure.
  2. Drafts and temperature fluctuations: If you feel drafts near your windows or notice significant temperature fluctuations when the windows are closed, it may indicate a seal failure. A properly sealed window should provide insulation and prevent air leakage, so any noticeable drafts or temperature changes suggest a problem with the seal.
  3. Visible damage: Inspect the window seals for visible signs of damage, such as cracks, gaps, or peeling. If you notice any of these issues, it is a clear indication that the seals have failed and need attention.

Effects of a failed window seal

A failed window seal can have several negative effects on both the functionality and appearance of your windows:

  1. Reduced energy efficiency: When a window seal fails, the insulating properties of the window are compromised. This can lead to increased heat loss during winter and heat gain during summer, resulting in higher energy bills as your heating and cooling systems work harder to maintain a comfortable indoor temperature.
  2. Condensation and moisture damage: As mentioned earlier, condensation between the glass panes is a common sign of seal failure. The presence of moisture can lead to mould and mildew growth, which can damage the window frames and surrounding areas. Additionally, excessive moisture can cause wood rot and paint damage, requiring costly repairs.
  3. Decreased aesthetic appeal: Failed window seals can also impact the appearance of your windows. Condensation and moisture between the panes can create an unsightly foggy or hazy appearance, making the windows look dirty and old. This can significantly detract from the overall aesthetic appeal of your home.

DIY methods for fixing a failed window seal

If you’ve found a failed window seal, there are DIY methods to temporarily fix it:

  1. Window defogging kits: These kits remove condensation by drilling small holes and using a cleaning solution. While temporary, they may not work for all seals.
  2. Applying sealant: High-quality silicone or window sealant can seal small gaps, but it’s only a temporary fix for minor damage.
  3. Installing window film: This improves insulation but doesn’t address the seal issue long-term.

Remember, these DIY fixes are temporary. For a permanent solution, consult a professional window repair service.

Hiring a professional to repair a failed window seal

When faced with a failed window seal, it is often best to enlist the help of a professional window repair or replacement service. These experts have the knowledge, experience, and tools to accurately diagnose the problem and provide appropriate solutions. Here are some reasons why hiring a professional is beneficial:

  1. Expertise and experience: Professional window repair technicians have extensive knowledge and experience in diagnosing and repairing window seal failures. They can identify the root cause of the problem and recommend the most effective and long-lasting solutions.
  2. Access to specialized tools and materials: Window repair professionals have access to specialized tools and materials that are necessary for repairing window seals. This ensures that the repair work is done correctly and that the window’s functionality and appearance are fully restored.
  3. Warranty and guarantees: Reputable window repair companies often offer warranties and guarantees on their work. You can relax knowing that if any issues come up after the repair, we’ll take care of them without charging you extra.

Preventing window seal failure

While it is not always possible to prevent window seal failures entirely, there are steps you can take to minimize the risk:

  1. Choose high-quality windows: Investing in high-quality windows from reputable manufacturers can significantly reduce the likelihood of seal failures. Most times, these windows are made to last and have warranties that protect against seal failures.
  2. Proper installation: Ensure that your windows are installed by qualified professionals who follow industry best practices. Proper installation is crucial in preventing seal failures caused by gaps or incorrect placement.
  3. Regular maintenance: Regularly inspect your windows for signs of damage or seal failure. Promptly address any issues to prevent further damage and ensure the longevity of your windows.
  4. Avoid extreme temperature fluctuations: Rapid temperature changes can place stress on window seals and contribute to their failure. Avoid exposing your windows to extreme temperature fluctuations whenever possible.

The cost of fixing a failed window seal

The cost of fixing a failed window seal can vary depending on several factors, including the severity of the seal failure, the type of window, and the extent of the necessary repairs. In some cases, a simple seal replacement may be sufficient, while in others, a complete window replacement may be necessary.

As a general guideline, repairing a failed window seal can cost anywhere from £100 to £400 per window. However, it is important to obtain quotes from reputable window repair companies as prices can vary significantly. It is also worth considering the long-term benefits of fixing the seal, such as improved energy efficiency and reduced maintenance costs.

Replacement options for windows with failed seals

In cases where the window seal failure is severe or extensive, replacing the entire window may be the best option. Window replacement offers several benefits, including:

  1. Improved energy efficiency: Many window designers often incorporate advanced technologies into newer windows, which enhance their insulation and energy efficiency. By replacing windows with failed seals, you can enjoy reduced energy bills and increased comfort.
  2. Enhanced aesthetic appeal: Window replacement allows you to update the look of your home and improve its curb appeal. With a wide range of styles, materials, and finishes available, you can choose windows that complement your home’s architecture and reflect your personal style.
  3. Increased property value: Upgrading to new, energy-efficient windows can significantly increase the value of your property. This is particularly valuable if you plan to sell your home in the future.

When considering window replacement, it is advisable to consult with a professional window replacement company. They can guide you through the selection process and provide expert installation to ensure optimal performance and longevity.

Final Thoughts

Windows losing their seal can be a frustrating problem for homeowners. However, by understanding the common causes of window seal failure and taking appropriate measures, you can prevent and address this issue effectively. Regular maintenance, proper installation, and choosing high-quality windows are crucial in preserving the functionality, energy efficiency, and aesthetic appeal of your windows. If the seal fails, you should seek advice from a professional window repair or replacement service to make sure you get a solution that lasts and works well. By investing in the care and maintenance of your windows, you can enjoy the benefits of a comfortable, energy-efficient, and visually appealing home.