Windows are often where homeowners notice it first because glass does
not absorb moisture. The location of the moisture - outside, inside, or
between panes - tells you what is most likely happening.
Start with one simple check: determine which surface of the glass
is wet before assuming there is a window problem.
What is condensation?
Common household condensation, sometimes described as window “sweating,” occurs when water vapor in the air contacts a surface cold enough for that vapor to change into liquid droplets.
1. Occasional fog or droplets can be normal. Short-lived condensation during weather changes, cooking, showers, or the beginning of heating season may simply reflect temporary humidity and temperature conditions.
2. Persistent or excessive moisture deserves attention. Repeated heavy condensation, frost, peeling paint, damp trim, or moisture spots on walls and ceilings can indicate that indoor humidity is too high or that another building or HVAC condition needs evaluation.
3. The window is often the indicator, not the source. Because glass is non-porous and often cooler than surrounding interior finishes, it is one of the first places excess airborne moisture becomes visible.
Explore our Condensation Guide to learn what causes window condensation and how to manage it. For your convenience, download the PDF or print a copy for easy reference.
