Glass & Window Repair
Failed Window Seals
One of the most common window and door issues that homeowners encounter is fogged glass, which is more commonly known as a broken seal. Just in case you don’t know what we are talking about, check out the photo above. Two of those four window panes have badly fogged glass.
When an insulated glass seal fails, there are probably one of three things you might see when looking through the glass: nothing different at all, condensation, or dirty / hazy glass. When a seal initially fails, nothing necessarily dramatic happens, and there is no visible evidence of a failed seal. A desiccant (drying material) around the perimeter of the glass unit will help to prevent moisture in the air from filling the space between the two pieces of glass. This will keep the glass looking fine, at least for a while.
Given enough time, moist air begins to fill the space between the two formerly-sealed pieces of glass. When temperatures remain fairly constant, you won’t notice this moisture in the glass. Only after there has been a fairly rapid change in temperature, either indoors or outdoors, will you see any evidence of a failed seal. This starts out as condensation between the two panes of glass. The photo below shows an example of a window on a home that just started showing evidence of a failed seal. This window looks perfectly fine most of the time, but occasionally you may notice a small band of condensate between the pieces of glass.
After time the amount of condensate, or fog, will get more and more noticeable. Soon a mineral deposit gets left on the glass, making it look dirty all the time, even when there is no condensate present. The photo below shows an example of another window with some faint, annoying deposits.
When window screens are present or when the glass is dirty, fogged glass like this may not be visible. If you have a home with numerous panes of fogged glass, you are probably not seeing every one, especially if the windows aren’t perfectly clean.
Once a window or door has had a failed seal for several years, the glass gets dirty enough to the point where it’s completely obvious all the time, and it becomes quite bothersome to look through the fogged glass. If you have a few panes of failed glass, odds are you will have more and more over time. You may want to consider replacing more than just the few lites of glass that have obvious issues to save money in the future.