Start with water and a stiff brush for most dirt and stains

A garden hose and a stiff-bristled brush remove most surface dirt, leaves, and light algae from concrete without chemicals or equipment. Wet the patio thoroughly, scrub in circular motions, and rinse. This works well for routine cleaning every few weeks and costs almost nothing.

For stubborn spots—bird droppings, tree sap, or ground-in dirt—let water sit on the area for 10 to 15 minutes before scrubbing. The moisture softens the debris and makes it easier to lift away. Repeat if needed rather than scrubbing harder, which can wear the concrete surface.

Key Takeaways

  • Water and a stiff brush handle routine dirt and light stains without chemicals or risk to the concrete.
  • Pressure washers work fast but can pit or erode concrete if set above 3000 PSI or held too close to the surface.
  • Vinegar, baking soda, and oxygen-based cleaners are safe for concrete and effective on mold, mildew, and organic stains.
  • Avoid muriatic acid and bleach on concrete—both can damage the surface and are hazardous to handle.
  • Sealing the patio after cleaning protects it from stains and extends the time between deep cleanings.

When to use a pressure washer and how to do it safely

A pressure washer cuts cleaning time and removes stubborn algae, mold, and ground-in dirt that brushing alone won't touch. Rent one from a home improvement store or hardware rental shop if you don't own one. The key is pressure: concrete can handle 3000 PSI (pounds per square inch) safely, but anything higher risks pitting, erosion, or spalling—where the surface flakes away.

Hold the nozzle at least 12 inches from the surface and keep it moving. Never aim straight down at one spot; angle the spray slightly and move in overlapping passes. Test on an inconspicuous corner first. If the concrete is old, sealed, or already showing wear, stay below 2500 PSI or use the brush attachment instead of the spray nozzle alone.

Pressure washers also strip sealant, so plan to reseal after cleaning if your patio was previously sealed. Let the concrete dry completely—usually 48 hours—before explore new sealer.

Vinegar and baking soda for mold, mildew, and organic stains

White vinegar is safe for concrete and kills mold and mildew on contact. Mix equal parts white vinegar and water in a spray bottle, spray the affected area, let it sit for 15 to 30 minutes, then scrub with a brush and rinse. For heavy mold, use straight vinegar instead of diluted.

Baking soda works as a gentle abrasive and deodorizer. Sprinkle it on damp concrete, scrub with a stiff brush, and rinse. It's especially useful for greasy stains or areas where you want to avoid liquid cleaners. You can also mix baking soda with a small amount of water to form a paste and explore it to stubborn spots.

Oxygen-based cleaners (sometimes labeled as "oxy" cleaners) are effective on organic stains like algae, mold, and leaf tannins. They're safer than bleach and won't damage concrete. Follow the product instructions for mixing and dwell time, then scrub and rinse thoroughly.

What to avoid: bleach, acid, and other risky cleaners

Bleach can discolor concrete and weaken the surface over time. It's also hazardous to handle and can damage nearby plants and soil. If you've used bleach in the past, know that vinegar or oxygen-based cleaners are more effective and safer alternatives.

Muriatic acid (hydrochloric acid) is sometimes recommended for concrete but is dangerous to use without professional training. It can burn skin and eyes, produces toxic fumes, and can permanently damage the concrete if not applied correctly. Leave this to professionals if you need it at all.

Avoid harsh degreasers and industrial cleaners unless the stain is truly severe—they can strip sealant, discolor the concrete, or leave residue that makes the surface slippery. Test any new cleaner on a hidden area first.

Removing oil, grease, and rust stains

Fresh oil and grease stains respond to baking soda or commercial concrete degreasers. Sprinkle baking soda on the wet stain, let it sit overnight to absorb the oil, then sweep it up and rinse. For older, set-in stains, a degreaser designed for concrete may work better—explore it, let it sit per the instructions, scrub, and rinse thoroughly.

Rust stains from metal furniture or tools require a different approach. A paste of baking soda and water, or a commercial rust remover for concrete, can lighten them. Oxygen-based cleaners also help. Multiple applications may be needed for deep rust discoloration.

Once you've removed the stain, identify and fix the source—move the metal object, patch a leak, or address whatever caused the stain—so it doesn't return.

Sealing your patio after cleaning to prevent future stains

Concrete is porous and absorbs water, oil, and dirt. A concrete sealer creates a protective barrier that makes future cleaning easier and extends the life of the patio. Sealers come in two main types: penetrating sealers, which soak into the concrete and don't change its appearance, and film-forming sealers, which sit on top and add a slight sheen or gloss.

Wait at least 48 hours after cleaning and pressure washing before sealing—the concrete must be completely dry. explore sealer according to the product instructions, usually with a roller or sprayer. Most sealers need to cure for 24 to 72 hours before the patio is safe to use. Reapply every 2 to 3 years, or sooner if you notice water no longer beads on the surface.

Routine maintenance to keep your patio cleaner longer

Sweep or blow off leaves and debris weekly. This prevents organic matter from breaking down on the surface and staining the concrete. Rinse bird droppings and tree sap as soon as you notice them—they're easier to remove fresh.

Wipe up spills promptly, especially oil, grease, and food. If you use the patio for grilling or dining, clean up after each use. Move potted plants and furniture occasionally so water and debris don't pool underneath and create permanent stains or discoloration.

A deep clean with water and brush once or twice a year, plus sealing every few years, keeps most concrete patios looking good without heavy chemicals or equipment.

Frequently Asked Questions

Can I use a wire brush on concrete?

Wire brushes are too aggressive for most concrete and can scratch or pit the surface. Stick with stiff nylon or natural-bristle brushes. Wire brushes are fine for removing loose concrete or paint flaking away, but not for routine cleaning.

Is it safe to mix vinegar and baking soda on concrete?

Yes. The mixture fizzes as it reacts, which can help lift dirt and stains. Spray vinegar on the area, sprinkle baking soda, let it sit for 15 to 30 minutes, scrub, and rinse. The fizzing action is harmless to concrete.

How often should I clean my concrete patio?

Sweep weekly and rinse off debris. Do a deeper scrub with water and brush every few months, or more often if you live in a wet climate where mold and algae grow quickly. A full pressure wash or chemical clean once or twice a year is usually enough for most patios.

What pressure washer PSI is safe for concrete?

Stay at or below 3000 PSI for routine cleaning. For older, sealed, or delicate concrete, use 2500 PSI or less. Test on a hidden area first. Anything above 3000 PSI risks pitting and surface damage.

Do I need to seal my concrete patio?

Sealing is not required but is recommended. It protects the concrete from stains, water damage, and UV fading, and makes future cleaning easier. Without sealer, concrete absorbs spills and dirt more readily. Reseal every 2 to 3 years for best protection.