Greene County
Pressure Washing

Concrete driveway

Driveways, walks and patios are where most people reach for a pressure washer. Concrete is tougher than siding, but a narrow jet can still scar the surface, and salt and deicers do slow damage of their own.

Start gentle, work up

Method
Detergent and a stiff brush, or a surface cleaner on flat areas.
Pressure
Start with a lower-pressure nozzle. Move up only if you need to.
Cleaners
Water and mild detergent. Hose off road salt in winter.

Pressure or soft washing

Soft wash Cleaner goes on first, a soft brush does the scrubbing, and a garden hose does the rinsing.
distance
Pressure wash A machine pushes water through a nozzle. The tip, the distance and the angle set how hard it hits. Start gentle, work up

Kärcher’s paving guide says concrete slabs are more delicate than natural stone and that a strong water jet can easily damage the surface. It suggests a medium-pressure cleaner with a scrubber attachment, or a rotary nozzle or a good stiff brush with water and mild detergent for tougher stains1.

On large flat areas, it recommends a surface cleaner with a rinse function. These spin the spray under a hood, carry the dirty water away, and work faster than a single nozzle1.

Nozzle and pressure

40° 25° 15° 0°
Spray angle by nozzle tip. A narrow angle puts the same water on one small spot; a wide fan spreads it out. Named in this guide: 15°. Warned against in this guide: the 0° jet.

We found no care guide that gives a pressure figure for home driveways, so we don’t print one.

Kärcher’s advice for its machines is to always start with one of the lower-pressure nozzles and move up to the turbo nozzle only when needed, and only on appropriate surfaces. It lists the 15 degree tip for general everyday cleaning2. With a rotary jet on paving, hold it nearly upright and keep it about 15 cm (6 inches) above the ground1.

Cleaners to use and avoid

Use

  • Water and mild detergent with a stiff brush1.
  • A garden hose to rinse off salt that cars carry onto the driveway and garage slab in winter3.
  • A breathable silane or siloxane sealer or water repellent. NRMCA says late summer, after a few dry days, is an ideal time to apply it3.

Avoid

  • Deicers made of ammonium sulfate, ammonium nitrate or magnesium-based salts, which NRMCA says are chemically aggressive and destroy concrete surfaces3.
  • Deicers of any kind on concrete in its first winter. Use clean sand for traction instead3.
  • Reaching for the turbo nozzle first2.

Protect plants and keep runoff out of drains

Cleaning chemicals can damage plants and grass. The Brick Industry Association’s advice holds for any surface: protect nearby plants, and where needed keep the cleaning solution and runoff off plants and the soil around them4. Soaking beds with plain water before and after, and covering what you can, is the practical version of that.

Street drains are not sewers. EPA reminds people that storm drains lead directly to local waterways, not to treatment facilities. Its tips for washing outdoors: use biodegradable, phosphate-free, water-based detergents, use as little as you can, wash on a driveway or yard rather than in the street, and send the wash water onto grass or gravel5. In Greene County, polluted runoff that enters the storm sewers is often discharged into local rivers and streams without treatment6, and Beavercreek asks residents not to dump anything down a storm sewer or drain7.

If you see suds, a rainbow sheen or an odd color in a ditch, stream or storm drain, Greene County asks you to report it to the County Engineer’s Office at 937-562-75008.

Common damage

  • Etched lines and scarsA strong water jet can easily damage a concrete surface1.
  • ScalingAggressive deicers and deicers on new concrete can make the surface flake away. This is a winter problem, not a washing one, but you will see it when you clean3.

When not to pressure wash at all

  • With a turbo or zero degree jet as your starting point2.
  • When the rinse water will run straight down the driveway into the street drain with cleaner in it. See the runoff section below.
  • When it is cold enough for the water to freeze on the surface. See the seasonal checklist.

Step by step

  1. Sweep and move thingsClear the driveway, sweep off loose debris and move cars and planters.
  2. Plan the runoffWork out where the water will go. Keep cleaner out of the street drain and away from the lawn edge.
  3. Pre-treat stainsScrub with water, mild detergent and a stiff brush.
  4. Start gentleRinse with the lowest-pressure nozzle that works, or a surface cleaner on flat areas. Move up only if you need to.
  5. Keep it movingUse steady, overlapping passes. With a rotary jet, hold it nearly upright about 6 inches off the surface.
  6. Seal laterIf you plan to seal, wait for dry weather. Late summer is ideal.

Before you start, read the safety page. If the job looks bigger than you want to take on, DIY or hire lays out what each way involves.

Sources

Every superscript number on this page points to one of these. Each was read on the date shown.

  1. How to clean pavers Kärcher. Checked 2026-10-26.
  2. Electric Pressure Washers (nozzle guidance) Kärcher. Checked 2026-10-26.
  3. CIP 2: Scaling Concrete Surfaces National Ready Mixed Concrete Association. Checked 2026-10-26.
  4. Technical Note 20: Cleaning Brickwork (August 2018) Brick Industry Association. Checked 2026-10-26.
  5. Stormwater Best Management Practice: Vehicle Maintenance and Washing (EPA-832-F-21-032F) U.S. Environmental Protection Agency. Checked 2026-10-26.
  6. Stormwater Basics Greene County, Ohio. Checked 2026-10-26.
  7. FAQs: Stormwater Program City of Beavercreek, Ohio. Checked 2026-10-26.
  8. Illicit Discharge & Illegal Dumping Greene County, Ohio. Checked 2026-10-26.