Sandstone, travertine and many of the pavers used around Brisbane pools and courtyards are considerably softer than concrete. They can be cleaned well — but the pressure and chemistry that suit a driveway will permanently damage them, and the damage is not reversible.
The two things that ruin them are the same two things people reach for first: high pressure, and acid.
Know what you actually have
The right method depends entirely on the material, and they are easy to confuse.
- Sandstone is porous and relatively soft. It stains readily and erodes under pressure, leaving a visibly pitted surface.
- Travertine and limestone are calcium-based. Acid dissolves them — vinegar, brick cleaner and many “concrete cleaners” will etch the surface within seconds.
- Concrete pavers are tougher, but the surface layer carries the colour. Strip it and you expose the grey aggregate underneath, permanently.
- Clay pavers handle more pressure than most, though the jointing sand will not.
- Granite and bluestone are the most forgiving, but still suffer if you attack the joints.
If you are unsure, test in a hidden corner and wait a day before judging. Damage often only becomes obvious once the surface dries.
Why pressure is the wrong first move
On soft stone, a pressure washer removes stone. Not dirt sitting on stone — the stone itself. The result is a lightly eroded surface that looks cleaner initially, then attracts dirt faster than before because you have opened the pores and increased the surface area.
It also blasts out the jointing sand between pavers. That matters more than people expect: the sand is what stops lateral movement. Remove it and pavers begin to shift, edges chip, and weeds establish in the gaps.
If pressure is used at all on these surfaces, it is at low pressure with a wide fan, kept moving, and never with a turbo nozzle.
Why acid is worse
Acid-based cleaners are sold widely and used constantly on surfaces they should never touch. On limestone and travertine the reaction is immediate — the surface dulls and pits where the acid sat. On sandstone, acid can mobilise iron within the stone and produce rust-coloured staining that was not there before.
It also tends to attack the mortar or jointing compound faster than the stone, which loosens everything.
What does work
Patience and the right chemistry, which for most natural stone means a pH-neutral or mildly alkaline cleaner rather than anything aggressive.
- Sweep and rinse first. Grit dragged across soft stone under a brush scratches it.
- Wet the surface thoroughly before applying anything. A saturated stone absorbs less cleaner and stains less.
- Apply a suitable cleaner and let it dwell. Dwell time does the work; scrubbing effort does not.
- Agitate with a soft to medium brush, not a wire brush, working with the grain of the stone where there is one.
- Rinse thoroughly, including surrounding areas, so residue does not dry on adjacent surfaces.
Organic growth — the green film in shaded areas — needs a biocidal treatment rather than force, for the same reason it does on any other surface. Removing the visible layer leaves the roots behind.
Brisbane-specific problems
Pool surrounds take chlorinated splash-out plus sunscreen and body oils, which build a film that is genuinely hard to shift and does not respond to water alone.
Shaded courtyards stay damp for months through the wet season, and lichen on sandstone roots deeply into the surface.
Leaf tannin staining from overhanging natives leaves brown marks that look like dirt but are dye. They need a different treatment entirely, and pressure will not touch them.
Sealing
Most natural stone benefits from a penetrating sealer, particularly around pools and outdoor kitchens where spills are constant. Use a penetrating rather than topical product — a film-forming sealer on stone around a pool is a slip hazard and looks wrong.
As with concrete, the stone must be completely dry before sealing, and Brisbane humidity means that takes longer than the instructions assume.
When to get help
If the surface is expensive, if it is around a pool, or if you have already tried something and it looked worse afterwards — stop before you compound it. Request a free quote and we will tell you what the surface is, what will lift, and what will not.
