Post-Construction Window Cleaning — Yarra Street, Abbotsford

Glass looks smooth and is not. The surface is porous enough for mineral deposits to key into it, which is why hard water marks survive a normal clean and look worse once the pane dries. And the clock matters: left long enough the deposit etches in, and then the mark is permanent and the pane has to be replaced.

A blade was never an option. The deposit is harder than it looks and new glass scratches under it, so the marks were dissolved instead: an acidic treatment to break down the carbonate, held long enough to work, then neutralised and rinsed so nothing was left to attack the frames. Panes were checked dry, because mineral shadow only shows once the water has gone.

• Mineral deposits dissolved rather than scraped
• Treatment neutralised and rinsed off glass and frames
• Each pane checked dry, not wet
• Frames and tracks cleaned after the glass
• Construction debris cleared from the sliding channels
• Before and after photographs supplied

• Mineral streaking removed across the full glazing
• No scratching on new panes
• No etching left in the glass, caught before it set
• Frames and tracks left clean and running