Key takeaways
- Fog between panes means a failed seal
- It cannot be dried out for long, so the glass unit is replaced
- A good frame can keep a new glass unit
What fog means
Double-pane windows are sealed units. When the seal at the edge fails, humid air gets in and condenses on the inside of the glass, making a cloudy haze that cannot be wiped away.
It can show up after years of sun, heat and movement.
Can it be fixed?
Drilling and defogging services exist, but results are often temporary. The lasting fix is to replace the glass unit, and many frames can keep the sash. If the frame is old or rotted, replacing the whole window is smarter.
A new unit also lets you upgrade the glass.
Fog on the outside or inside
Fog on the outside of the glass is normal condensation from humidity and cool glass and wipes off. Fog on the inside surface points to indoor humidity. Only fog between the panes means a failed seal.
Related services
Quick answers
Does foggy glass hurt energy performance?
A failed seal loses the insulating gas and some of the window's performance.
Is foggy glass covered by the manufacturer?
Some manufacturers cover failed seals for a period. Check the paperwork and ask us to help.
Ready to talk it through? Get a free estimate or call 800-224-9245.