Can you pressure wash pavers and patios without wrecking them?
Yes, but it's risky. High pressure strips the jointing sand from the gaps, pits the surface and exposes the aggregate beneath — permanent, and it looks worse after the first rain. If you must do it yourself, cap the machine at 1500 PSI, use a wide fan nozzle, and never a 0-degree jet. Better still, run a flat surface cleaner and re-sand the joints.
The jointing sand goes first
The sand packed between pavers isn't decoration. It locks the units together, stops them rocking underfoot and keeps weeds out. A high-pressure jet — anything a hire-shop machine puts out at close range — lifts that sand straight out of the joints. You'll watch it wash across the paving in grey ribbons. What's left is an open gap. The pavers lose their interlock, start to shift, and the joints turn into a seed bed for weeds and moss inside a single season.
Re-sanding is a real job — sweeping in fresh kiln-dried sand, compacting it, sometimes stabilising the top — not a quick fix most people budget for after a clean. So the paving that looked sharp for a week slowly loosens, and the next heavy Sydney downpour finishes the job by flushing out whatever sand survived. The clean that was meant to smarten the patio ends up shortening its life. That's the trade high pressure quietly hides from you.
Then it pits the surface and exposes the aggregate
Pavers are made to be seen from the top, and that top face is the dense, finished, weather-resistant layer. Concrete pavers have a fine cast surface; below it sits coarser aggregate — the stones in the mix. Hold a narrow jet too close, or drag a 0-degree tip across the slab, and you erode that skin. The surface goes from smooth to sandpaper. Once the aggregate is exposed it holds dirt, grows algae faster and can never be brought back. It's gone for good.
This is the part that surprises people. The paving looks fine while it's still wet from cleaning — dark, even, spotless. It's only when it dries, and especially after the first rain, that the pitting shows: pale blotches, a rough patch where the wand lingered, tiger stripes from an uneven pass. There's no sealer or top-up that reverses it. You're now choosing between replacing pavers or living with the marks. Slow and gentle beats fast and permanent every single time here.
Sandstone and travertine are softer still
Concrete pavers are tough compared with natural stone. Sandstone, travertine and limestone are softer, more porous and far easier to scar. A jet that merely roughens concrete will carve visible channels into sandstone and open the surface so it drinks up more water and grime afterwards. Blasting a soft stone strips its weathered outer skin — the very layer doing the protecting — and once that's gone the stone weathers faster, not slower. On natural stone, high pressure buys a short-term look at the cost of long-term harm.
Travertine and tumbled pavers have filled holes and a soft, honed face that a jet will pockmark in seconds. On these, high pressure is almost always the wrong tool. A gentle wash, the right detergent and a bit of patience lift the growth without touching the stone. If your patio is natural stone and it's gone green or grey, the answer isn't more pressure — it's less, applied properly. Get that wrong once and the repair bill dwarfs what a careful clean would have cost you.
If you must do it yourself, do it like this
Rules if you're set on hiring a machine. Cap it at 1500 PSI — plenty for grime, short of destructive. Fit a wide fan nozzle, 25 or 40 degrees, and never the red 0-degree pencil jet, which is the single fastest way to wreck a slab. Keep the tip well back, roughly a hand's length or more, and keep it moving in even, overlapping passes. Test an out-of-the-way corner first, then check that corner once it's dry — not just while it's wet.
Better than any nozzle is the right tool: a flat surface cleaner — the round housing that rides on the paving and spreads the pressure through two spinning jets under a shroud. It cleans evenly, without the stripes, and won't gouge as long as you keep moving. Then re-sand the joints afterwards with kiln-dried sand and compact it back in. Yes, it's more steps than blasting away with a wand. That's rather the point — the shortcuts are exactly what cost you the pavers.
What a careful clean actually costs
Schmick cleans pavers, patios and paths as part of driveway pressure cleaning, from $180. We match the pressure and method to the surface — firm on solid concrete, gentle on sandstone and travertine — and we re-sand jointed paving when it needs it, so the clean holds instead of loosening a week later. Most driveways land between $180 and $420 by area, according to our price book, and sealing is a set add-on if you want the finish to hold on longer.
You don't have to guess which camp your paving falls into, or what it costs. The instant quote returns a firm, bookable price in about 60 seconds, and it holds unless the place turns out to be materially different from what you described. Tell it the surface and the area, and you'll know the number before anyone sets foot on your patio — no jet marks, no pale blotches after rain, and no re-sanding bill you didn't see coming.