The Usual Causes Behind Window Seal Failure

Windows seals help prevent heat from escaping your home during winter and keeps the cold air in during the summer. They also keep drafts from entering your home and wreaking havoc on your home’s indoor comfort and air quality. However, like most window components, the seals can fail. But why does it happen in the first place? We take a look at some of the common causes below:

Subpar Installation

Window seal failure could be a result of poor workmanship on the part of the installation team.. For instance, the seals might have been damaged during installation, a defective sealant was used, or it wasn’t given enough time to set. If this is the case, you can still have them resealed to keep your windows intact.


Windows are likely to “sweat” or accumulate water droplets on the surface whenever there’s a difference between indoor and outdoor temperatures. When you see some forming on the interior or exterior of your windows, make sure to wipe them off. If this isn’t routinely done, it can lead to mold growth on the glass panes, affecting the surrounding seals. If you notice any signs of mold or discoloration, make sure to clean the affected window thoroughly with vinegar or an alcohol-based cleaner. This is to effectively eliminate the spores without damaging the glass.

Fluctuating Temperatures

Constant temperature changes can also lead to window seal failure. When sunlight hits the window, it absorbs heat, which leads to expansion and pushes out air. By nighttime, the window contracts as it cools and draws in air and humidity. This cycle is known as solar pumping and causes stress to the window seals, which leads to trapped moisture. This leads to foggy window panes, which means the seals have failed and need to be replaced.

Dealing With Broken Window Seals

If you’ve already had your windows for several years, they can be more susceptible to seal failure due to natural wear and tear. But if they were recently installed and are only a couple of years old, you can assume that there may be a problem with the product or the installation behind them. It’s still best to have a professional window and door replacement check the seals for damage. Regular maintenance also helps detect broken seals so you can get them addressed as soon as possible.

Turn to Renewal by Andersen® for your replacement window and door needs. To get started, you can reach us at (206) 775-7533 or fill out our convenient online contact form to schedule a consultation. We’re proud to serve Seattle, WA, and the surrounding areas, including Mercer Island, Kirkland, Edmonds and Bellevue.

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