Interior condensation reflects surface temperature and humidity
Warm indoor air can release moisture when it meets a cold glass surface. Cooking, showers, drying laundry, plants and humidifiers all contribute to indoor humidity.
Improved glass temperature can reduce the risk, but ventilation and moisture control remain part of the solution. Heavy coverings can also limit warm room air from reaching the glass.
Room-side moisture
Review indoor humidity, ventilation, coverings and interior glass temperature.
Exterior moisture
Can occur naturally during humid conditions and often clears with weather changes.
Between panes
Signals an insulated-glass seal failure that surface cleaning cannot correct.
Water at the sill
May be condensation or leakage; weather timing and location help separate the causes.
Exterior condensation can be normal
Moisture sometimes forms on the outdoor surface when the glass is cooler than humid exterior air, particularly on clear mornings. It may indicate that interior heat is not warming the outer pane as much.
This usually clears as sun, wind or temperature changes. Confirm the moisture is truly on the outside before treating it as a sealed-unit failure.
Moisture between panes means the seal has failed
Haze, droplets or mineral patterns trapped within an insulated unit indicate that the edge seal no longer maintains the cavity. Cleaning the exposed surfaces will not remove it.
If the frame and sash remain suitable, the sealed glass unit may be replaceable. The repair should include correct measurements and glass specifications for the existing window.
Details that make a repair request more useful
- Which glass surface is wet?
- Does it happen during cold weather or humid mornings?
- Is moisture trapped between panes?
- Are exhaust fans and indoor humidity being managed?
