What Is Sandblasting?
A plain-English explanation of how abrasive blasting works, what it can clean, what it can damage, and how we choose the right media for your building.
- Specialist-trained operators
- Method-matched to your surface
The Short Answer
Sandblasting — properly called abrasive blast cleaning — fires a stream of graded media at a surface under air pressure. The impact removes paint, rust, soot, carbon, graffiti, scale and weathering, leaving a clean, keyed surface ready for painting, coating or repointing. The original media was sand; modern blasting uses garnet, olivine, crushed glass, sodium bicarbonate and other safer materials, so today the word "sandblasting" really means "blast cleaning" — the process, not the media.
How It Actually Works
A compressor delivers clean, dry air to a blast pot, which meters the chosen media into the airstream. The mix travels along a hose to a nozzle, where it is aimed at the surface. The media hits the coating or substrate and removes it by mechanical impact — essentially controlled scratching and chipping at a microscopic scale.
Two variables do the work: the media (its hardness, shape and grade) and the pressure at the nozzle. A hard, angular garnet at high pressure cuts through thick industrial paint on steel. A soft, round soda at low pressure lifts paint off delicate masonry without scratching the face. Same machine, completely different result — that is why matching the method to the substrate matters more than anything else.
The Media We Use (and Why Not Sand)
Silica sand was the original abrasive, but breathing silica dust causes silicosis — a serious, irreversible lung disease — so it has no place on a modern site. We use garnet and olivine (hard, angular minerals for steel and hard brick), crushed glass (a sharp but inert recycled abrasive), and sodium bicarbonate (soft, water-soluble, ideal for delicate surfaces and where run-off must be environmentally safe). Each is graded to a specific mesh size so the cut is predictable and repeatable.
What Sandblasting Can Clean
Structural & Mild Steel
Cast Iron & Metalwork
Hard Brick & Engineering Brick
Stone & Sandstone
Timber
Concrete, Floors & Forecourts
Graffiti & Memorial Headstones
What It Can Damage — and What We Use Instead
Abrasive blasting removes material mechanically, so it always takes a little of the substrate with the coating. On soft Victorian brick it strips the fired outer skin, leaving the softer core exposed to weather. On weathered sandstone it takes millimetres off the face. Neither can be put back. That is why we will never just "blast it and see" on a sensitive surface.
For listed buildings, soft stone and delicate brickwork we use superheated steam (DOFF) cleaning — heat and low-pressure water, no abrasive. For facades that just need grime, algae and pollution crusts lifted, our industrial & commercial power washing service is often enough. And once a surface is clean and stable, pointing & lime pointing protects it for decades.
Wet vs Dry Blasting
Dry blasting is the standard — media and air only, fast and clean cutting, with spent media to collect. Wet (vapour) blasting injects a small amount of water at the nozzle to suppress dust, which we use on occupied sites, near traffic, and anywhere airborne dust must be controlled. Wet blasting cuts slightly less aggressively and leaves a damp surface, so the choice is driven by the site, not the substrate.
How We Decide What to Use
Every job starts with a survey: the substrate, the coating or soiling, access, neighbours, and the finish you need. From that we choose the media, the pressure, and whether to go dry or wet. On anything historic or delicate we run a test patch and agree the result before full works — no surprises on the main elevation.
If you are trying to budget a job, our sandblasting house cost UK guide sets out typical per-square-metre rates and what drives them up or down. And if you want to see the method in action, our process video shows the setup, the clean and the finish.
Frequently Asked Questions
Is sandblasting the same as blast cleaning?
Blast cleaning is the umbrella term for any process that fires a stream of media at a surface under pressure. Sandblasting is one type of blast cleaning — the one that originally used sand. Today we use garnet, olivine, glass, soda and other safer media, so 'sandblasting' and 'blast cleaning' are used interchangeably in trade and on the street, even though the original silica sand is no longer used on site.
Is sandblasting dangerous?
Done badly — with dry silica sand, no extraction and no PPE — it is a serious health risk. Done properly with modern media, enclosed or sheeted work areas, and the right RPE, the risk is controlled. We never use silica sand on site, we contain spent media, and the operator wears full respiratory protection.
Will sandblasting damage my brick or stone?
It can, if the wrong media and pressure are used on a soft or weathered face. Victorian brick and sandstone lose their fired skin and weathered surface, which cannot be put back. On those substrates we use a softer method — superheated steam or a fine soda blast — and we test a patch first. Read our guide to whether sandblasting is safe for old brick and stone.
Can you sandblast wood?
Yes, with a fine media at low pressure — it strips paint, varnish and weathering without gouging the grain. See our timber blast cleaning page for how we handle beams, doors and barns.
Does sandblasting remove rust from steel?
It is the most effective way to take rust and old paint off structural steel and cast iron and leave a keyed surface ready for priming. See structural steel blast cleaning and metalwork & ironwork blast cleaning.
How much does sandblasting cost?
It depends on the substrate, the media, access and the finish you need. We have a full breakdown of sandblasting house cost in the UK, with typical per-square-metre rates.
Not sure if sandblasting is right for your surface?
Send us a couple of photos and a postcode. We'll come out, survey the property, and put a written price in your hand within days — not weeks.