Why double-pane windows fog
A double-pane window is really one sealed unit: two panes of glass with a spacer and a seal around the edge. That unit is called an insulated glass unit, or IGU. Over the years, sun, heat, and weather break down the seal. Moist air gets in, and you see haze, streaks, or droplets between the panes that no amount of cleaning will remove. More in the guide why double-pane windows fog.
What we replace
We replace the sealed glass unit, not the whole window. We measure the existing unit and the frame, order a new unit built to that size, and install it in your existing sash or frame. This works for picture windows, sliders, casements, many vinyl and aluminum windows, and patio door panels.
People often ask about window seal repair when they see fog or condensation between the panes. We don't re-seal or defog the old unit. Foggy or condensation-filled double-pane windows are fixed by replacing the sealed insulated glass unit in the existing frame.
Is it worth fixing?
A failed seal doesn't make a window unsafe, but it does cost you the clear view, and the unit insulates less well once the seal has failed. If the frame is in good shape, a new unit makes the window clear again without a full window replacement.
Common questions
Do you do double-pane window repair?
Yes. Foggy or condensation-filled double-pane windows are fixed by replacing the sealed insulated glass unit in the existing frame, not by re-sealing or defogging the old one.
Can you just clean out the fog?
No. The moisture is inside the sealed unit. The lasting fix is a new sealed unit.
Do I need a new window frame?
Usually not. If the frame and sash are sound, we replace only the glass unit.
How long does it take?
We measure first and order the unit to size. Once it arrives, installation is usually quick. We'll give you a time when we schedule.
Related services
Helpful guides
- Why double-pane windows fog up
- Glass types: tempered, laminated, obscure, and double-pane
- What to photograph before you call
Where we work
Burien, South Park, Georgetown, West Seattle, White Center, Normandy Park, Tukwila, SeaTac, Des Moines, Federal Way, Kent, Seattle, Mercer Island, King County.