How to Clean a Concrete Patio: My Bleach Hack That Actually Works

How to Clean a Concrete Patio: At a Glance

The full process for getting a concrete patio sparkling clean comes down to seven steps:

• Sweep and clear all leaves, dirt, and debris with a push broom and blower
• Pressure wash the patio for a baseline clean
• Water nearby grass and plants to protect them from bleach runoff
• Wet the stained areas of the patio with the hose
• Apply undiluted bleach with a pump sprayer (or pour direct on the worst spots)
• Scrub the bleach into the concrete with a push broom
• Pressure wash the whole patio for a final clean rinse

Why I Needed a Concrete Cleaner That Could Actually Deliver

After a long, cold, stormy winter, our patio was looking rough. Dirt, leaves, and grime had built up in every corner. So, like any determined DIY-er, I started cleaning our concrete patio step by step.

What My Patio Looked Like Before

What I Tried First

First up: clearing the debris. I used a push broom, a blower, and then gave it a quick rinse with the hose. It already looked better, but not clean.

Next, I brought out the big guns: my pressure washer. If you have ever seen the results in Revive Your Old and Weathered Wood Fence, you know why I had high hopes. And it did help lift a lot of the surface grime, but there were still stubborn stains hanging on for dear life.

These photos are after the pressure washing. Yuck. I knew I was going to have to get creative to get these stubborn stains cleaned off my concrete patio.

The Concrete Cleaner Method that Didn’t Work

Naturally, I went with the conventional wisdom that I found recommended on the internet. I mixed up a solution in my pump sprayer: five parts water to one part bleach. I sprayed it directly on the worst spots, let it sit for 5 to 10 minutes, gave it a solid scrub with the push broom, then rinsed it off with the pressure washer again.

And nope. The stains were still there.

What Did Work: My Bold Concrete Cleaner Move

At this point, I decided to go bold. Out came the bottle of straight, undiluted bleach.

But wait. There is a method to this madness, and a few important precautions.

Why Bleach Works on Concrete Stains 

Concrete is porous, which means stains soak into the surface, not just sit on top of it. Diluted cleaners and most store-bought concrete cleaners can lift surface dirt, but they cannot reach the staining particles that have penetrated below the top layer. Undiluted bleach has the chemical strength to oxidize organic stains (mildew, algae, planter rings, food spills, leaf tannins) deep in the pores, which is why it outperforms diluted mixes on set-in stains. The trade-off is that undiluted bleach is harsh on plants, grass, and untreated wood, so prep matters.

Step 1: Protect Grass and Plants Before You Clean

Before cleaning your concrete patio with bleach, water any nearby grass or plants. This helps protect them from accidental runoff or splash damage.

Why Watering First Matters

Plants and grass absorb whatever liquid is at root level. If the soil around your patio is dry when bleach runoff hits, the roots will pull the diluted bleach in. If the soil is already saturated with plain water, the bleach gets diluted further and rinsed past the root zone before it can do damage. The same logic applies to the bleach itself: a thoroughly wet patio holds the bleach on the surface where you want it, instead of having it soak immediately into the dry pores.

Step 2: Wet the Stained Area

Start by wetting the area of your concrete patio that is stained. This helps the bleach spread more evenly and keeps it from soaking in too quickly.

Step 3: Apply the Concrete Cleaner

I poured bleach straight from the jug for some areas, but ended up preferring the pump sprayer for more control. Using the undiluted bleach directly on the stain gave me the results I was after.

Pump Sprayer vs. Pouring From the Jug

The jug pour is fastest for big, badly stained sections, but you waste a lot of bleach and you get drips and splashes outside the stain area. The pump sprayer is the better default: it lets you apply an even mist over a stain, control the boundary so you do not hit grout lines or expansion joints, and use less bleach overall. I keep one sprayer dedicated to bleach so I never accidentally cross-contaminate with other cleaners.

How Long to Let the Bleach Sit

Five to ten minutes is the sweet spot. Less than five and the bleach has not penetrated deep enough to lift set-in stains. More than ten and the bleach starts to dry on the surface, which leaves white residue you have to scrub off later. If you are working in direct sun, stay closer to five minutes because evaporation speeds up. If it is cool or overcast, ten is fine.

Step 4: Scrub Like You Mean It

Grab your push broom and scrub thoroughly. I mean really work that concrete cleaner into the surface.

Step 5: Pressure Wash for a Final Rinse

Once everything has had a good scrub, rinse the whole patio off with a pressure washer. Not only does this remove the bleach, it gives you that satisfying “sparkly clean” finish.

When NOT to Use Bleach on Concrete 

Bleach is the right call for most outdoor concrete, but there are cases where it can cause problems.

Sealed and Colored Concrete 

If your patio has a clear sealer on top, bleach can dull or discolor the sealer over time, especially with repeated use. For sealed concrete, start with a milder cleaner (a few squirts of Dawn in warm water plus a stiff brush) and only escalate to diluted bleach for stubborn spots. Colored or stamped concrete is also at risk: bleach can fade the integral color or break down the surface treatment. Test bleach on an inconspicuous corner first and watch it for 24 hours before treating the whole patio. If you have an oil-based stain (engine oil, grease from a grill), bleach will not lift it. Use a dedicated concrete degreaser or kitty litter to absorb the fresh oil first, then bleach the residual discoloration.

Best Concrete Cleaner for Different Stains 

Not every stain responds to the same treatment. Here is what actually works for the four most common types of concrete patio stain.

Oil and Grease Stains 

For fresh spills, cover the area immediately with kitty litter or sawdust to absorb as much oil as possible. Sweep up the absorbent material after a few hours, then scrub with hot water and dish soap (Dawn works well). For older oil stains, a poultice of baking soda and a degreaser left to sit overnight pulls oil out of the pores. Bleach does not touch oil; do not bother with it for grease.

Rust Stains 

Rust comes from metal furniture legs, planters, or rebar bleeding through. The fix is an acid-based rust remover (lemon juice or white vinegar for light rust, or a dedicated oxalic-acid concrete rust remover for heavy stains). Apply, wait 5 to 10 minutes, scrub with a stiff brush, rinse. Bleach does not work on rust either; it can actually set the stain.

Mildew, Algae, and Black Stains 

This is where bleach shines. Black streaks under shaded areas, green algae near grass and downspouts, and pink mildew in damp corners all respond to undiluted bleach with the method described above. For prevention, a 50/50 bleach-water mix sprayed monthly during humid season keeps the regrowth down.

Planter Rings and Watering Stains 

Those circular stains under terra cotta pots are a mix of mineral deposits from hard water and organic gunk from soil. Bleach handles the organic part. For the mineral deposits, a follow-up treatment with diluted CLR or white vinegar lifts the calcium and lime. Going forward, set planters on saucers or pot feet to prevent the rings from forming again.

How to Clean a Concrete Patio Without a Pressure Washer 

You do not actually need a pressure washer for this method. You need it for the baseline clean and the final rinse, but both can be substituted with a strong garden hose plus more elbow grease.

The Hose-and-Scrub Method 

Replace the pressure washer baseline with a stiff push broom and a hose with a high-pressure nozzle. Scrub the whole patio in 4-foot sections, rinse, repeat. This takes about twice as long as a pressure wash but gets you to the same starting point. For the final rinse, the same nozzle plus a slow walk-around works fine; you just won’t get the dramatic “sparkly” finish a pressure washer gives. If you only deep-clean your patio once a year, renting a pressure washer for one Saturday ($50 to $80) is still cheaper than buying one. If you clean more often or you also wash decks, fences, or vehicles, owning one ($150 to $300) pays itself back in two seasons.

The Satisfying Before and After

Check out these before and afters: on the left, you can see planter rings and random splotches, and on the right, poof, gone. That deep clean magic? All thanks to this powerful DIY concrete cleaner routine.

How to Keep Your Concrete Patio Clean After the Deep Clean 

The deep clean lasts longer if you build a few low-effort habits into your spring and summer routine.

• Sweep weekly during leaf-fall season so debris does not have time to stain
• Move planters to saucers or pot feet to prevent ring stains from re-forming
• Spot-treat new stains within 24 hours (fresh stains lift in minutes; set-in stains take hours)
• Apply a clear concrete sealer every 2 to 3 years for long-term stain resistance
• Use a 50/50 bleach-water spray monthly during humid months to keep mildew and algae from coming back

Cost and Time: How Much It Takes to DIY a Patio Clean

Honest breakdown of what cleaning a concrete patio actually costs and takes:

Materials: Bleach runs $4 to $6 per gallon (you will use 1 to 2 gallons for a typical small patio). Add a pump sprayer ($15 to $25 if you do not own one), a push broom ($25 to $40), and pressure washer rental ($50 to $80 for a weekend) or purchase ($150 to $300). All-in for someone starting from zero: $90 to $150 for rental + supplies. If you already own the broom and pressure washer: under $10.

Time: A focused half-day for a typical small patio (about 4 to 5 hours), or a long Saturday for a large patio with multiple stained zones.

Our Patio Is Back and Open for Summer Fun

Some of you might remember when I hired help from Facebook Marketplace to pour our patio in Install a Concrete Sidewalk (and More!). It has held up beautifully (honestly, no regrets), but if I could go back, I would probably seal it to make cleaning easier.

That said, I am glad I have this method up my sleeve. When it comes to cleaning concrete patios, this has become my go-to trick. Bleach might not be fancy, but it is hands-down the best concrete cleaner I have tried for deep, set-in stains.

If you also want to refresh your concrete porch or front walkway, my guide on how to paint a concrete porch walks through that process from prep to finish coat.

How We Use Our Patio to Gather and Entertain

We love using our patio for everything from family hangouts around the fire pit to hosting backyard dinners and celebrations. It is one of the most-used spaces in our home, especially once the weather warms up. If you want to see how we styled these areas or get all the links and sources, check out this post about our fire pit lounge area and this one with our outdoor dining setup.