Bluestone and Concrete Paving Cleaning — St Helen's Road, Hawthorn East

Bluestone and concrete want opposite things. Bluestone has iron in it, so acidic products can pull it to the surface as rust-coloured bloom, and softer inclusions pit under too much pressure. Concrete is more porous, holds growth deeper and takes more work, but push it and the cement paste comes off and the aggregate stands proud.

Each material was treated on its own terms, with no acid near the bluestone and pressure set separately for each. The harder part is the join: clean the two areas to different standards and the boundary between them shows, and a patchy yard looks worse than a dirty one. Both were checked dry, not wet: stone and concrete darken differently and neither can be judged with water on it.

• Materials identified and treated separately
• No acidic product used anywhere on the bluestone
• Pressure set independently for stone and concrete
• Joins between the two areas matched by eye
• Both surfaces assessed dry, not wet
• Before and after photographs supplied

• Whole yard cleaned to one tone across both materials
• No rust bloom in the bluestone
• No pitting or exposed aggregate in the concrete
• Boundary between the surfaces reads as one yard