What appears to be a little fog or grime around your windows may be a bigger mystery brewing behind the glass.
What It Means
When a window seal fails—particularly in a double-pane (insulated glass unit)—the argon gas or vacuum escapes, allowing moisture and air to infiltrate the space between the panes. This leads to foggy, hazy, or dirty-looking windows that no amount of Windex can fix. Over time, it compromises energy efficiency and allows the slow creep of mold and rot.
What to Look For
• Fog or condensation between the panes (not on the surface)
• Discoloration or black streaks along the edge of the glass
• Cracked or separating caulk around the window trim
• Subtle drafts even when windows are closed
Detective’s Advice
Don’t jump to replace the entire window. Often, you can:
Re-seal the perimeter if it’s just the caulking or glazing failing
Replace the insulated glass unit (IGU) if the internal seal has blown
✖️ Avoid full frame replacement unless the window frame is rotted or severely warped
Why spend more when a targeted fix solves the case?
Case evidence from a recent inspection—note the foggy pane, degraded sealant, and overall condition. Stay vigilant, homeowners. Even the smallest crack can open the window to bigger problems.