Condensation in Glass

How to Address Condensation Issues in Insulated Glazing Units (IGUs) for Wood Windows.

Premium wood windows, especially those crafted with premium materials like Mahogany or Accoya, are often considered the epitome of elegance and durability. These windows, built with advanced techniques and high-end materials, are designed to last a lifetime. However, even with their exceptional construction, a common issue can arise—condensation within Insulated Glazing Units (IGUs).

 Let’s dive into why this happens, the frustrations it causes, and the best solutions to resolve the problem while preserving the quality and appearance of your windows.

 Why Does Condensation Occur in IGUs?

 Modern high-end windows, especially those manufactured within the last 10 to 20 years, incorporate low-profile gaskets in their IGUs. These gaskets are a key component when using true divided lites, where the muntins or glazing bars need to be very slim to maintain the aesthetic appeal. However, these low-profile gaskets, while effective in their design, are often the weak link in the long-term performance of the IGU.

Over time, these gaskets can fail, leading to condensation between the panes of glass. This not only detracts from the clarity of the glass but also gives the impression that the windows are perpetually dirty—an especially frustrating issue for homeowners who invested in high-quality, custom wood windows.

The Challenges of Fixing Condensation in Wood Windows

Glass Condensation

 When condensation appears within an IGU, it’s a sign that the sealed unit has failed. For wood windows, particularly those with intricate or custom molding, addressing this issue can be a delicate process. Here are the two primary approaches to resolving condensation in IGUs:

 1. Replacing the Glass Only

One solution is to cut the moldings surrounding the defective glass, replace the glass unit, and remake the moldings to match the original design. While this method preserves the existing sash and overall structure, it comes with several challenges:

- Labor-Intensive: Removing the moldings and ensuring the new ones match the original design is a painstaking process that requires skilled craftsmanship.

- Matching Aesthetics: Even with meticulous attention to detail, the new glass and moldings may not blend seamlessly with the surrounding panes, creating a visual inconsistency.

- Reusing Low-Profile Gaskets: Reinstalling the same type of low-profile gasket increases the likelihood of a repeat failure in the future.

 While this approach may be necessary for historical preservation or when original aesthetics are non-negotiable, it’s not always the most practical or long-lasting solution.

 2. Replacing the Entire Sash

A sometimes more effective and durable solution is to replace the entire sash. By doing so, you can opt for a higher-quality IGU with a standard gasket that offers a longer warranty and improved performance. This method provides several advantages:

- Improved Durability: Standard gaskets are less prone to failure, significantly reducing the risk of future condensation.

- Simulated Divided Lites: For windows with grid patterns, switching to simulated divided lites can maintain the classic look while offering better structural integrity and energy efficiency.

- Seamless Aesthetics: Replacing the entire sash ensures a uniform appearance, as the new sash will be crafted to match the original design and all glass will be of the same.

While some homeowners may hesitate to move away from true divided lites, the benefits of using a standard gasket often outweigh the aesthetic compromise, particularly when long-term reliability is a priority. Preventing Condensation in the Future

Investing in high-quality materials and thoughtful design is essential to minimize the risk of condensation in IGUs. When considering window replacements or upgrades, prioritize the following:

- Warranty: Opt for IGUs with longer warranties, which typically indicate superior performance and durability.

- Material Selection: Premium woods like Accoya and Mahogany, combined with robust weather stripping, can enhance the longevity and functionality of your windows.

-Professional Installation: Ensure your windows are installed by skilled professionals who understand the nuances of wood window construction and glazing.

Trust the Experts in Wood Window Restoration

At RP Windows & Doors, we specialize in preserving and enhancing the beauty of wood windows while addressing common issues like condensation in IGUs. Whether you’re dealing with failed seals or warped sashes or simply want to upgrade your windows for better performance, our team has the expertise to deliver results that exceed expectations.

Don’t let condensation detract from the beauty and functionality of your wood windows. Contact us today to discuss your project and discover how we can help restore your windows to their original quality—or better.

Credit to Parrett Windows and Doors for suppling all the replacement sashes on this magnificent home in Scarsdale NY