Fog on windows that you can’t wipe off happens to double-pane windows when the seal around the glass fails. Air penetrates the space between the panes and moisture gradually builds up and leaves fog. The process for how to fix foggy windows requires that you remove the moisture and rebuild the seal. In this article, the window experts at PJ Fitzpatrick teach you how.

How to Fix Foggy Windows Directions

1. Before you begin, confirm that the moisture is not on the outside of your window.
2. Remove sash with fogged panes so that you can work on it.
3. Look for screws on the side of the sash. Wooden windows will have screws and vinyl windows might have screws.
4. Use a flat head or Phillips screwdriver to take out the screws and expose the edges of the glass panes.
5. If you don’t see screws, then the sash is fusion welded. This is typical on vinyl windows.
   1. Use a flat head screwdriver or putty knife to pop out glazing strips along glass.
6. Once glass edges are exposed, slide putty knife or utility knife between panes and sash. This breaks remaining silicone sealant.
7. Thoroughly wash panes inside and out. Use fresh newspaper as you wipe the glass so that it does not get too soggy and disintegrate.
8. Once glass is clean, apply a bead of silicone caulk around sash edges.
9. Put panes back in place.
10. Install new silica spacer bars. The fresh silica will soak up any moisture that might penetrate in the future.