How to Pressure Wash a Patio Without Damaging It

The short version: use a fan nozzle (never a pinpoint jet), keep the nozzle moving, hold it a reasonable distance from the surface, and work with the grain of the paving pattern rather than blasting directly down into joints. Getting this wrong is exactly how a pressure washer strips out jointing sand, damages mortar, or etches the surface of softer natural stone.

Step by step

1. Clear the patio first. Sweep off loose debris, leaves and grit, and move furniture and planters out of the way.
2. Choose the right nozzle. A fan (flat) spray nozzle spreads the pressure over a wider area and is much less likely to gouge the surface than a narrow pinpoint or turbo nozzle. Save the narrower nozzles for stubborn stains only, and test on an inconspicuous area first.
3. Work at a safe distance and angle. Keep the nozzle roughly 200-300mm from the surface as a starting point, angled slightly rather than pointing straight down, and adjust based on how the surface reacts.
4. Work in overlapping passes in the direction of the paving joints rather than across them, to reduce the risk of blasting sand or jointing compound straight out.
5. Rinse as you go so you can see progress and avoid over-washing one small area.
6. Re-sand or re-point joints afterwards if any sand or jointing compound has washed out — leaving joints empty allows weeds to establish and can let the paving shift over time.

Different surfaces need different care

• Concrete block paving: generally the most forgiving surface, but joints still need re-sanding afterwards.
• Natural stone (sandstone, limestone, slate): softer stones like sandstone and limestone can etch or pit under high pressure or a narrow nozzle — use lower pressure and a wider fan pattern.
• Old or historic paving, or reclaimed stone: take extra care, or consider a lower-pressure clean with a dedicated patio cleaning product instead, since the surface may already be worn thin.
• Resin-bound or resin-bonded surfaces: check manufacturer guidance specifically — some resin-bound surfaces have maximum recommended pressure and distance settings, and getting too close can strip the resin.

Common mistakes

• Using a turbo/pinpoint nozzle on the whole area. Fine for a small stubborn stain, but far too aggressive for general cleaning.
• Holding the nozzle too close. This is the single biggest cause of etched or gouged patios.
• Pressure washing directly across joints repeatedly. Strips out sand and jointing material, leading to loose paving and weed growth.
• Not re-sanding joints afterwards. Empty joints invite weeds and ants, and paving can start to shift.

See our related guide on how often you should pressure wash a patio or driveway to avoid over-cleaning, which can accelerate wear on softer surfaces.

Equipment you'll need

Beyond the pressure washer itself, a stiff outdoor broom for clearing debris beforehand and sweeping displaced jointing sand afterwards is genuinely useful. For re-sanding joints afterwards, kiln-dried jointing sand (brushed into the joints and lightly watered or compacted depending on the product) is the standard approach for block paving; natural stone with mortared joints instead of sand-filled ones will need re-pointing rather than re-sanding if joints have been damaged. Consider hearing and eye protection too — pressure washers are loud and can throw back debris and dirty water.

If the underlying paving itself is damaged rather than just dirty, cleaning won't fix that — see our guide on why patios sink or crack for the difference between a surface clean and a structural repair.

Dealing with stubborn stains

Oil stains, rust marks and organic staining (leaves, berries, sap) sometimes need more than water pressure alone to shift. A dedicated patio or driveway cleaning product, applied and left to work before rinsing, is usually more effective and gentler on the surface than simply increasing the pressure or switching to a narrower nozzle. For oil stains specifically, an absorbent product left to draw the oil out before cleaning gives better results than pressure washing alone, which can spread the stain rather than remove it.

How long does it take?

A typical domestic patio (say, 15-25 square metres) usually takes somewhere between one and three hours to pressure wash thoroughly, depending on how dirty it is, the surface material, and how much re-sanding is needed afterwards. Building in time for the re-sanding step rather than rushing it is worth it — a patio cleaned quickly but left with empty joints will look tidy for a few weeks before weeds and instability creep back in.