How to Clean a Concrete Patio: A Step-by-Step Guide
A dirty concrete patio drags down the whole look of your backyard, and the grime only gets harder to remove the longer it sits. Learning how to clean concrete patio surfaces properly is a straightforward weekend job that costs little and makes the space look nearly new again. Whether you’re dealing with green algae, tire marks, barbecue grease, or just a dull gray film from years of weather, the right approach brings the surface back without damaging the concrete.
In this guide, you’ll get the exact process: the supplies to gather, the cleaning solutions that actually work, and the order of steps that prevents streaks and stains from coming right back. We’ll also cover how to handle the stubborn spots—oil, rust, and mold—and whether you should seal the patio once it’s clean.
Why Concrete Patios Get Dirty
Concrete is porous. Water soaks in, carrying dirt, pollen, and minerals with it, and then evaporates, leaving the residue behind. Over time that residue builds into a gray, chalky film that makes even a structurally sound patio look neglected.
The specific culprits depend on where you live. In damp or shaded yards, mildew and green algae are the main problems—they thrive in moisture and leave dark or green patches. Under trees, you’ll battle sap, leaf stains, and pollen. Near a grill or a driveway, grease spatter and tire grime are the usual suspects. And in areas with hard water, mineral deposits can leave a whitish haze, especially around sprinklers.
The good news: almost all of this lifts with the right cleaner and a little elbow grease. Concrete is tough, which means you can be aggressive with it—within reason—without worrying about scratching the way you would with painted deck boards.
How Often Should You Clean a Concrete Patio?
Most patios need a proper cleaning once or twice a year. A good rhythm is a deep clean in the spring to clear away winter grime, followed by a lighter touch-up in the fall before you pack up the outdoor furniture.
You’ll know it’s time when you see any of these:
- A dull gray or green film that won’t rinse off with a garden hose
- Dark stains from leaves, acorns, or berries that have sat for weeks
- Slippery patches, which usually mean algae or moss has taken hold
- Visible oil or grease marks near the grill or furniture
- A chalky white haze from hard-water sprinkler overspray
If you let grime sit through a full season, it becomes harder to remove and more likely to stain permanently. A quick spring clean is cheaper and easier than a restoration job later.
Photo by Max Vakhtbovych via Pexels
Tools and Supplies You’ll Need
You can clean a concrete patio with items you likely already own, plus one or two cleaning products from the hardware store. Here’s the full list:
- Stiff-bristle push broom or deck brush
- Garden hose with a spray nozzle, or a pressure washer (1,500–2,500 PSI)
- 5-gallon bucket
- Dish soap or a dedicated concrete cleaner (Krud Kutter, Simple Green, or Zep are solid choices)
- Oxygen bleach (sodium percarbonate), such as OxiClean, for organic stains
- White vinegar or muriatic acid (only for the toughest mineral stains)
- Baking soda or kitty litter for oil spots
- Rubber gloves and eye protection
- Long-handled squeegee (optional, for faster drying)
Pressure washers get the job done faster, but a stiff brush and a hose work fine for a small to medium patio. If you don’t own a pressure washer, many hardware stores and home centers rent them for around $40–$80 per day.
How to Clean a Concrete Patio in 6 Steps
This method works whether you’re scrubbing by hand or using a pressure washer. Follow the order—clearing the surface first and rinsing last prevents most of the streaks people complain about.
1. Clear the Space
Move every planter, chair, table, and grill off the patio so you have an open surface to work on. Sweep thoroughly with a push broom to remove loose dirt, leaves, and grit. If you skip this step, you’ll just be grinding debris into the concrete while you scrub.
2. Pre-Treat Oil and Grease Spots
Oil needs attention before you do the general wash. Sprinkle baking soda or clay-based kitty litter over each stain, let it sit for 30–60 minutes to absorb the oil, then sweep it up. For heavy stains, apply a degreaser (Simple Green or a dedicated concrete degreaser) and let it dwell for 10–15 minutes before you start scrubbing.
3. Mix and Apply Your Cleaner
For general cleaning, a few squirts of dish soap in a bucket of warm water handles most dirt. For algae, mildew, or leaf stains, mix oxygen bleach with water according to the package directions—it brightens the concrete and kills the organic growth without the harshness of chlorine bleach.
Apply the solution to a manageable section (about 10×10 feet at a time) so it doesn’t dry before you get to it. If you’re using a pressure washer, many models have a soap-dispensing nozzle or tank for exactly this step.
4. Scrub the Surface
Work the cleaner in with a stiff-bristle brush, using a circular motion. Focus on high-traffic areas and any visible stains. For a pressure washer, hold the wand at a 45-degree angle and keep the nozzle 6–12 inches from the surface. Move in smooth, overlapping passes—if you go too slowly or hold the nozzle too close, you can etch the concrete and leave permanent lines.
5. Rinse Thoroughly
Rinse from the highest point of the patio down toward the edges, so dirty water flows away from the clean areas and doesn’t pool. Keep rinsing until the water runs clear. Leftover soap residue dries into a dull film, which defeats the whole purpose.
6. Let It Dry Completely
Give the patio a full day to dry before you put furniture back. If you’re planning to seal it, wait 24–48 hours, or until the concrete is bone dry—sealer applied to damp concrete turns cloudy and peels.
Photo by Alexander Zvir via Pexels
How to Remove Stubborn Stains
Some stains shrug off soap and water. Here’s how to hit the ones homeowners ask about most:
| Stain Type | Best Remedy | Notes |
|---|---|---|
| Oil & grease | Degreaser or baking soda poultice | Absorb first, then scrub; may need two rounds |
| Rust | White vinegar or oxalic acid | Let it soak, then scrub; rinse well |
| Mold, mildew, algae | Oxygen bleach (OxiClean) | Kills growth and brightens; safer than chlorine |
| Leaf & acorn tannins | Oxygen bleach | Works best on fresh stains |
| Mineral / hard water | White vinegar (mild) or muriatic acid (heavy) | Acid etches concrete—dilute and rinse fast |
A note on chlorine bleach: it will lighten stains, but it’s harsh on surrounding plants and can leave the concrete looking patchy. Oxygen bleach does the same job more gently and is the better default.
For the deepest-set stains, a poultice works when scrubbing doesn’t. Mix your cleaner (or a product like a commercial stain remover) with an absorbent material such as diatomaceous earth to form a paste, spread it a quarter-inch thick over the stain, cover it with plastic, and let it sit for 24 hours. As it dries, it pulls the stain up out of the pores.
Should You Seal Your Patio After Cleaning?
Sealing is optional, but it’s the single best way to keep your patio looking clean for longer. A penetrating or acrylic sealer fills the surface pores so water, oil, and dirt can’t soak in as easily—which means stains stay on the surface where a quick rinse removes them.
Plan on sealing every two to three years. A 5-gallon bucket of quality sealer (foundation-sealing brands like Foundation Armor or Eagle run $150–$250 and cover roughly 300–500 square feet, depending on porosity) is a modest investment compared with redoing a stained patio.
Apply sealer only after the patio is completely clean and dry, using a sprayer or roller, and keep the area dry for at least 24 hours. If you want to learn more about the broader costs involved, our stamped concrete patio cost guide breaks down what a full concrete surface project runs.
Frequently Asked Questions
Can I use dish soap to clean a concrete patio?
Yes. A few squirts of dish soap in warm water is an effective everyday cleaner for light dirt and grime. It won’t kill algae or lift oil stains on its own, so pair it with oxygen bleach or a degreaser for those jobs.
Is it safe to pressure wash concrete?
It is, as long as you use 1,500–2,500 PSI, hold the nozzle at a 45-degree angle, and stay 6–12 inches from the surface. Higher pressure or a closer hold can etch the concrete and leave visible lines.
Will vinegar damage concrete?
Mild white vinegar is safe for spot-cleaning mineral and light rust stains. Avoid regular, heavy vinegar soaks—over time the acid can etch the surface. For serious mineral buildup, use a properly diluted concrete-safe acid and rinse immediately.
How do I keep my concrete patio from getting dirty so fast?
Sweep it weekly, rinse spills promptly, and seal the surface every two to three years. Keeping planters off the concrete and trimming back overhanging branches also cuts down on the organic stains that cause most of the mess.
Do I need to seal a concrete patio?
No, sealing is optional. But unsealed concrete absorbs stains and water much more readily, so sealing is worth it if you want less maintenance and a longer-lasting clean.
The Bottom Line
Cleaning a concrete patio is a low-cost, high-reward job. With a stiff brush, a hose or rented pressure washer, and the right cleaner for the stain, you can turn a grimy gray slab back into a bright, usable outdoor space in an afternoon. The key is doing it in the right order—clear, pre-treat, scrub, rinse, dry—and sealing afterward so the results last.
If your patio has cracks that appeared while you were cleaning, address them before they spread. Our guide on how to repair cracks in a concrete driveway covers the same repair techniques that work on patio slabs. And if the concrete is beyond saving, a new concrete walkway or fresh surface may be the better long-term fix.
For more detail on concrete care and sealing, the team at This Old House has practical walkthroughs, and Better Homes & Gardens keeps up-to-date guidance on outdoor cleaning. Get the grime off now, and your patio will be ready for the season before you know it.
