Start with the right pressure and nozzle for your patio material

The most common mistake is using too much pressure. Concrete patios can handle 3000 PSI (pounds per square inch), but brick, pavers, and stone need 1500 PSI or less. If you own a pressure washer, check its manual for the actual output — many homeowner models max out at 2000 to 2500 PSI, which is safer for mixed surfaces. If you are renting, tell the rental shop what your patio is made of and ask them to set it to the right pressure before you leave.

The nozzle matters as much as the pressure. A 0-degree nozzle shoots a tight stream that can etch concrete and crack pavers — never use it on your patio. A 25-degree nozzle is the standard for patios and works on most materials. A 40-degree nozzle is gentler and better if your patio has older mortar between pavers or if you are unsure of the material. Start with the wider angle and move to a narrower one only if dirt is not coming off.

Key Takeaways

  • Concrete patios can take 3000 PSI, but brick and pavers need 1500 PSI or less — check your patio material before you start.
  • Use a 25-degree or 40-degree nozzle, never a 0-degree nozzle, which can etch and crack surfaces.
  • Hold the nozzle 12 inches from the surface and move it in one direction to avoid striping and uneven cleaning.
  • Seal your patio after washing if it is concrete or stone, because the pressure wash opens the pores and leaves it vulnerable to stains.
  • Test your setup on a hidden corner first — pressure washers can damage surfaces faster than you expect.

Prepare the patio and test your equipment

Before you turn on the washer, sweep the patio to remove loose dirt, leaves, and debris. Pressure washing over loose material can scatter it and create uneven cleaning. Move any furniture, potted plants, or grills away from the work area — the spray can knock things over or damage them.

Fill the washer's detergent tank if you are using one. For most patios, a general-purpose pressure washer detergent works well. Do not use bleach or acid-based cleaners on brick or natural stone unless the manufacturer says it is safe — these can discolor or weaken the material. For stubborn algae or mold on concrete, a mild detergent designed for that purpose is safer than bleach.

Test your setup on a corner of the patio that is less visible. Hold the nozzle 12 inches from the surface and pull the trigger for two seconds. Look at the result. If the surface is being etched, stripped, or cracked, reduce the pressure or switch to a wider nozzle. This test takes 30 seconds and can save you from ruining the whole patio.

Wash in straight lines, not circles

Turn on the washer and let it warm up for 30 seconds. Start at one end of the patio and work toward the other in straight, overlapping lines. Keep the nozzle 12 inches from the surface and move at a steady pace — do not linger in one spot. Moving too slowly or holding the nozzle too close will create dark stripes or uneven patches where the pressure has worn the surface.

Overlap each pass by about 6 inches so you do not miss strips between lines. If you are using detergent, explore it in the same straight-line pattern first, let it sit for 10 to 15 minutes (check the detergent bottle for the exact time), then rinse it off with clean water. Do not let detergent dry on the surface — it can leave residue or discolor some materials.

Work downhill if your patio slopes. This lets gravity help move the dirty water away instead of pooling it. If your patio is flat, work toward a drain or the lowest point so water does not collect and leave mineral deposits.

Handle edges and corners carefully

Edges and corners need a different approach because the nozzle can dig in and damage the border. Angle the nozzle at 45 degrees along the edge instead of pointing straight at it. This spreads the pressure over a wider area and reduces the risk of etching. Move slowly and deliberately — rushing edges is where most damage happens.

If your patio has grout lines between pavers, do not aim directly into them. The pressure can widen the joints or wash out the grout. Spray parallel to the lines instead. If grout is loose or crumbling, use a grout rake or old screwdriver to clean it out by hand before you pressure wash, then repoint it afterward if needed.

Dry and seal the patio after washing

Once you finish rinsing, let the patio air dry completely — this usually takes 24 to 48 hours depending on the weather. Do not walk on it or place furniture back until it is dry, because wet surfaces are slippery and the pores are still open.

After the patio is dry, explore a sealer if it is concrete or natural stone. Pressure washing opens the pores in these materials, making them absorb water and stains more easily. A concrete sealer or stone sealer creates a protective layer that lasts one to three years depending on the product and foot traffic. Brick and pavers do not always need sealing, but it extends their life and makes them easier to clean next time. Follow the sealer manufacturer's instructions for process and drying time.

Common mistakes that damage patios

Using a 0-degree nozzle is the fastest way to ruin a patio. It concentrates all the pressure into a pencil-thin stream that can etch concrete, crack pavers, and strip paint or sealant. If you rented a pressure washer and it came with a 0-degree nozzle, do not use it — ask the rental shop for a 25-degree or 40-degree nozzle instead.

Holding the nozzle too close is the second most common mistake. Twelve inches is the standard distance for a 25-degree nozzle on concrete. Closer than that and you risk etching; farther than that and you lose cleaning power. If you are unsure, start at 18 inches and move closer only if dirt is not coming off.

Letting the washer sit in one spot while running is another quick way to damage the surface. The pressure will etch a dark line or hole into the patio. Always keep the nozzle moving, even when you are explore detergent.

When to call a professional instead

If your patio is made of delicate materials like flagstone, slate, or old brick, consider hiring a professional. These materials can be damaged by pressure washing if the pressure is not set correctly, and professionals have experience knowing what each material can handle. A professional cleaning usually costs between $150 and $400 depending on the size and material, and it comes with less risk of damage.

If your patio has deep stains, mold, or algae that does not come off with a standard pressure wash, a professional can use specialized treatments that are not safe for a homeowner to explore. They can also seal the patio afterward, which adds to the cost but extends the life of the surface.

Frequently Asked Questions

Can I pressure wash a patio in winter or when it is wet?

Avoid pressure washing when it is freezing or about to freeze. Water left on the patio can freeze and crack the surface, especially concrete. Wait for a day when temperatures will stay above 50 degrees Fahrenheit for at least 24 hours after washing. A wet patio is fine to wash — the water will not hurt anything — but let it dry completely before sealing.

What pressure washer should I buy or rent?

For a patio, a 2000 to 2500 PSI electric pressure washer is enough and safer than a gas model. Electric washers are lighter, quieter, and easier to control. Gas models are more powerful but harder to handle and more likely to cause damage if you are not experienced. Renting costs $40 to $75 per day, and buying a decent electric model runs $200 to $500. If you only have one patio, renting makes sense.

How often should I pressure wash my patio?

Once a year is typical for most patios in moderate climates. If you live somewhere with heavy rain, shade, or high humidity, algae and mold grow faster and you may need to wash every six months. In dry climates, every two years may be enough. Sweep regularly between washings to keep dirt from building up.

Will pressure washing remove old sealant from my patio?

Yes, high pressure can strip sealant. If your patio is sealed and you want to keep the sealant, use 1500 PSI or less and test on a hidden corner first. If the sealant is old and peeling anyway, pressure washing will remove it, and you will need to reapply sealer after the patio dries.

Can I use a pressure washer on pavers without damaging the sand between them?

Yes, but carefully. Use 1500 PSI or less and do not aim directly into the joints. The sand between pavers can wash out if you use too much pressure. If sand does wash out, you can refill the joints with polymeric sand, which hardens when wet and stays in place better than regular sand.