Facade Cleaning · 10 August 2026
Glass Curtain Walls: What Causes Soiling and How Often to Clean
Glass curtain walls look sharp, but they are also sensitive to soiling — dust, exhaust residue and mineral marks can dull their transparency fast. Knowing what causes the soiling is the first step to setting the right cleaning interval.
The glass curtain wall is one of the most popular facade systems for plaza and residential projects. But its flat, reflective surface also makes soiling the most visible — dust build-up, mineral marks left after rain, or exhaust residue in high-traffic areas show up quickly on glass.
Understanding where that soiling comes from helps determine both the cleaning frequency and the right method.
What causes most of the soiling on a glass facade?
There are three main sources: airborne dust and particulate build-up, mineral marks left by water droplets drying after rain, and exhaust or soot residue in high-traffic or industrial areas. On buildings near the coast, salt crystals are a separate factor.
Why do mineral marks form, and how can they be reduced?
Hard water leaves mineral residue behind as it dries on glass; this build-up becomes more visible over time and gets harder to remove with classic methods. Working with deionised (pure) water reduces the risk of this build-up, because there is almost no mineral content left behind.
Are composite and aluminium components as sensitive as glass?
Composite panels and aluminium framing do not show soiling as visibly as glass, but over time they can experience colour fading and surface dulling. Avoiding harsh chemicals applies here too; organic, environmentally friendly agents are preferred.
How is the right cleaning interval determined?
Giving a fixed number would be misleading — location, traffic density, proximity to the coast and facade orientation (south-facing surfaces soil differently) all play a role. A site survey assesses the facade's current condition and a building-specific maintenance interval is recommended.
In short
Frequently asked
How often should a glass curtain wall be cleaned?
There is no fixed interval; it depends on location, traffic density and facade orientation. A building-specific recommendation is given during the site survey.
How can mineral marks be prevented?
Cleaning with deionised (pure) water reduces the risk of mineral residue being left behind.
Are composite panels cleaned the same way?
Yes, with pure water and organic agents where needed; no harsh chemicals are used.
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