Heritage Sandstone Facade — Graffiti Removal Without Stone Damage

The brief

A typical brief in this category: a heritage-listed sandstone facade hit by spray-paint taggers, with several tags across roughly 40m² of weathered sandstone. Council heritage rules generally prohibit acid wash, pressure washing or chemical strippers on listed stonework, and a conservator’s advisory for this kind of surface would usually point to dry ice or, at much greater cost, chip-and-replace stone.

Engagement on a job like this would typically start with a sample-area test request from the heritage architect — standard process for listed work.

How the work would run

Sample test. Before any work is scoped, a small sample area — around 0.5m² — would be run on an inconspicuous lower corner, with the conservator and heritage architect on site to inspect. Pressure would be tuned around 50-60 PSI with a 60-degree fan nozzle. On sandstone, paint typically lifts while the stone surface stays unmolested at this pressure range — sign-off would be sought before the main work proceeds.

Main work. Tags would be worked in sequence, using a lower-pressure technique throughout. Heritage stone is generally more forgiving than paint or steel for this kind of cleaning, but the surface texture has to be preserved exactly.

Documentation. Pre/during/post photos at every 1m² grid square would be standard, with the conservator typically visiting once during the work and once at sign-off.

What a job like this typically delivers

In a scenario like this, the expectation is that tags remove cleanly with no ghosting visible from a normal viewing distance, and that on close inspection the original sandstone weathering pattern and mortar joints stay intact. A documentation pack of this kind is what supports heritage architect sign-off and council records.

This is the kind of work we’re set up to deliver for council heritage cleaning panels and conservation architects — the documentation discipline matters as much as the cleaning technique, and any specific outcome claim for a real job would need to come from that job’s own sign-off record, not this illustrative example.