As moisture evaporates, it leaves behind white, powdery streaks or "riverbed" patterns on the glass.
For a permanent fix, follow this process: resealing double pane windows
Typically made of polyisobutylene (PIB), this keeps moisture out and gas in. As moisture evaporates, it leaves behind white, powdery
Cosmetic Damage & Minor Frame Issues. Surface-level problems – light scratches, chipped paint, small dents, loose hardware – rarel... Argo Glass & Windows Show all Method What it is Best For Estimated Cost Resealing / Defogging Drilling small holes to clean and dry the interior. Clear view on a budget; does not fully restore R-value. $70 – $120 IGU Replacement Swapping the old glass unit for a new factory-sealed one. Restoring full insulation and clarity without buying a new frame. $100 – $400 Full Window Replacement Installing an entirely new frame and sash. Warped or rotting frames; major energy efficiency upgrades. $450 – $1,600+ Step-by-Step DIY IGU Replacement If your frame is in good shape, replacing only the glass unit is the most effective "repair." Identify and Measure $70 – $120 IGU Replacement Swapping the old
The cost of resealing double pane windows varies depending on the method, size of the window, and location. On average, you can expect to pay:
Press a razor blade gently against the glass edge where it meets the spacer. If the sealant is powdery or pulling away, the secondary seal has failed irreparably.
