Why Do Windows Leak From the Top and How to Fix It

Windows are an essential part of any building, providing natural light, ventilation, and aesthetic appeal. However, when a window starts leaking from the top, it can lead to a host of problems, including water damage, mold growth, and decreased energy efficiency. Understanding the causes of window leaks and how to fix them is crucial for maintaining a healthy and comfortable living or working environment.

Common Causes of Window Leaks from the Top

There are several reasons why a window may leak from the top, and it’s important to identify the root cause to find an effective solution. Here are some of the most common causes:

Improper installation: If the window was not installed correctly, it can create gaps or openings that allow water to enter. This is especially common with specialty-shaped windows, bay and bow windows, and custom-made windows, which require extra care during installation to prevent leaks.
Damaged or missing flashing: Flashing is a thin metal or plastic material used to divert water away from vulnerable areas of the window frame. If the flashing is damaged, missing, or improperly installed, it can allow water to penetrate the wall and cause leaks.
Deteriorated caulking or sealant: Over time, the caulking or sealant around the window frame can crack, dry out, or become brittle, creating gaps that allow water to enter. This is a common issue with older windows or windows that have been exposed to harsh weather conditions.
Structural issues: Leaks at the top of the window can also be caused by problems with the building’s structure, such as cracks in the wall above the window or improper drainage. These issues can allow water to enter the wall and run down along the window frame, causing leaks from the top.

How to Fix Window Leaks from the Top

Once you’ve identified the cause of the window leak, you can take steps to fix the problem. Here are some common solutions:

Resealing the window: If the leak is caused by deteriorated caulking or sealant, you can reseal the window by removing the old sealant and applying a new, high-quality sealant. Be sure to clean the surface thoroughly before applying the new sealant to ensure a strong bond.
Replacing the flashing: If the flashing is damaged or missing, you’ll need to replace it. This may require removing the window and installing new flashing before reinstalling the window. It’s best to hire a professional for this task to ensure it’s done correctly.
Repairing the wall: If the leak is caused by structural issues in the wall, you’ll need to repair the wall before addressing the window. This may involve patching cracks, replacing damaged bricks or mortar, or addressing drainage problems.
Replacing the window: In some cases, the best solution may be to replace the window entirely, especially if it’s old, damaged, or improperly installed. A new window can provide better insulation, improved energy efficiency, and a tighter seal to prevent future leaks.

Regardless of the cause of the window leak, it’s important to address the problem promptly to prevent further damage and maintain the integrity of your building. If you’re unsure about the cause or how to fix the leak, it’s best to consult with a professional window contractor or building inspector for guidance.