Are cloudy glazing marks surface spotting or a sealed-unit problem?

Are cloudy glazing marks surface spotting or a sealed-unit problem?

Cloudiness has several causes. Droplets drying can leave minerals, and runoff or pollution can create streaks. A deteriorated insulating-glass seal can allow moisture between panes, producing misting that exterior cleaning cannot reach. Surface condensation alone does not establish unit failure.

Assess where marks sit, how they change with weather and how a controlled clean affects a small area. Some external deposits may need specialist treatment, but etched surfaces and damaged coatings are not ordinary dirt and may not be recoverable through washing.

This distinction guides the next step: cleaning advice for accessible contamination or glazing assessment for internal defects. Do not use progressively stronger treatment when the cause is uncertain. Provide photographs and any history of changing misting, leaks or past cleaning when enquiring. A cleaning trial can show improvement to an external surface; it cannot certify the seals or restore moisture-damaged sealed units.