Surface moisture is different from moisture between sealed panes. Identify the location before purchasing cleaning or replacement work.
Where is the cloudiness?
Pella explains that moisture between panes of insulated glass can indicate a seal problem. Some products have different construction, so identify the window rather than assuming all multi-pane designs are identical.
- Outside surface: dew can appear when weather and glass temperature allow condensation.
- Room-facing surface: record indoor moisture patterns and nearby activities.
- Between panes in a sealed insulated unit: arrange a manufacturer or glazing assessment.
- A fixed surface mark: ask whether cleaning, specialty treatment, or another review is appropriate.
What changes should you report?
Record damp sills, nearby staining, recurring pooling, or a haze that never clears. Do not dismiss these as a dirty-glass issue. Equally, temporary dew on the outside does not by itself prove a defective window; Andersen describes exterior condensation as a weather-related phenomenon.
A cleaning visit is not a humidity assessment, leak investigation, or insulated-glass repair. Those are separate questions even when they are first noticed while the glass is being cleaned.
How can you prepare for an assessment?
- Photograph the window when the haze is visible.
- Record the time, weather, affected rooms, and whether it later clears.
- Find the brand, model, installation date, and warranty records if available.
- Ask which next step fits the observation before authorizing repeated cleaning.
Common questions
Can a cleaner remove fog inside a sealed window?
Ordinary cleaning addresses exposed surfaces, not the sealed space within insulated glass. Have the window assessed for the appropriate repair or manufacturer support.
Does morning dew outside mean my window has failed?
Not necessarily. Exterior condensation can occur under suitable weather conditions. Its location and pattern matter more than the presence of moisture alone.
Helpful references
General care-planning guidance—not a glazing inspection, leak diagnosis, or elevated-work procedure. Follow the instructions for your actual windows, films, and coatings.