What Causes and How to Fix Window Discoloration

Discoloration on a home’s windows is a disheartening effect. Windows are an expensive investment, and the stark problem of discoloration is evident on a deeper matter, slowly creeping in to detrimentally cause ruin to this necessary aesthetic of your home.

window discoloration

Breaking Down Discoloration: Moisture as the Cause

Discoloration often means one thing: moisture. Every homeowner becomes on high alert when the word moisture is thrown around as the root cause of a problem. Moisture can wreak havoc when left unchecked, but as far as your windows are concerned, they don’t look wet, so is there really a moisture problem?

Unfortunately, for double-pane windows, discoloration and moisture go hand-in-hand. Sure, it may not feel wet, but it’s definitely a sign that water has been there, many times, streaking its way across the surface of the window, leaving its trail of damage along the way.

The discoloration manifests because there’s a presence of mildew or mold, which is growing because the double-pane window offers the best place for mildew and mold to thrive, grow, and spread, feeding on whatever moisture is lingering, trapped between the panes, the humidity, and the darkness that allows it to live.

Typically, discoloration is found in black or dark-hued streaks all across the surface of the window, but you might notice that the discoloration is either black or brown, or it can even be white, orange, and green, depending on the mold and mildew that’s growing there.

Preventing Moisture to Prevent Discoloration—And More

What’s causing the moisture to be trapped between the double-pane window resulting in the discoloration? The answer could be as simple as a high level of relative humidity inside your home, which is the amount of moisture and water vapor that’s produced inside of your home, the humidity outside, and the subsequent air exchange rate at which your home replaces the damp air with dry, fresh air.

Okay, maybe it isn’t that simple—the atmosphere inside of your home is actually a sensitive matter, and ultimately with the relative humidity, outside humidity, and air exchange rate, that’s a lot to consider!

Moisture could also be getting into your window because of a poor caulking seal. Homeowners know that re-caulking windows are a must-do springtime chore to be done at least once a year.

Windows that have hard caulking, missing strips of caulking, or spots where the caulking has chipped or deteriorated away completely are prone to moisture problems, and therefore—discoloration. This especially becomes a problem if the gutter system hasn’t been cleaned either, causing water run-off that’s finding its way into your windows.

The bottom line: channel water as best as you can away from your house. This includes ensuring that your gutters and downspouts are functioning as they should, and you don’t have any sure-fire signs of moisture in your basement. Protect your foundation by installing a waterproofed barrier because then you’ll do much more than preventing discoloration in your windows, you’ll prevent a future of massively expensive foundation repairs.

Resolving Discoloration on Your Windows

Once you understand the root cause of discoloration in your windows, it’s best to tackle that first then you can focus on fixing your discolored windows. Moisture is tricky to pinpoint, so it can be trial and error for a while until you single out where the source could be coming from.

fixing window discoloration

It’s time to fix your windows. For some homeowners, the discoloration can be a telltale sign that the entire window needs to be replaced. You might be wondering if your moisture problem hasn’t been resolved, won’t the new window be subject to discoloration, too? Good news for you, new windows are designed and installed with discoloration-resistant film to prevent this from happening.

If you opt to repair the window and the project calls for the replacement of the glass pane, then you will have the expense of this plus the installation—although you can install it yourself.

If you live in an older house, your windows may be unique in their shape or size, which is something to consider if you’re looking to replace the glass.

You can tackle the discoloration on the window with some liquid glass cleaner, a safety razor, a bristle brush, and an oxalic acid cleaner. Your first step should be to loosen the dirt that stubbornly sits on the surface of the window by using a hog-bristle brush, mild detergent, and water. Use the liquid glass cleaner on the windowpanes and then take your safety razor to scrape away at thick, hard-to-remove debris.

When you’ve managed to remove the majority of the dirt, wipe the windowpane with your detergent solution, finishing it up with your steel wool pad.

Next, use the oxalic acid cleaner to create a paste solution, applying it to the window surface with a microfiber cloth. This will remove all of the discolorations from your window, which will now look as good as new.

Repair or Replace—What’s Better with Discoloration?

Keep in mind that when going through the process of rigorously cleaning your windows, especially if discoloration has hit more than one, seems arduous and time-consuming, then it might be better to simply replace them.

It’s not a cop-out if new windows come with the guarantee of not just being discoloration-resistant, but having a slew of other advantages, too.

For replacing your windows, you’ll want to check off everything that is essential for you as a homeowner.

  • Great insulation and energy efficiency
  • Variety of styles, colors and options
  • Professional installation and installers

At Feldco, we check off everything on this list and provide you with nothing but the best. Speak to a product specialist and get a free quote online today.

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