Overall, we recommend Zep Purple Pressure Wash (US$13.98, The Home Depot). Alkaline cleaners are great for lifting oil stains, grease stains, and other petroleum-based stains from concrete. It's an added benefit that you can use it with a pressure washer, making the job that much easier.
Vinegar or baking soda: These natural cleaners work well to clean cement patios with stubborn charcoal or rust spots. Mix equal parts vinegar and water, scrub the patio with the mixture, then give it a good rinse. If stains don't dissolve, try undiluted vinegar.
A hose or pressure washer can help remove mold, mildew or water stains from concrete patios and driveways. If staining persists, use a mold remover or bleach solution to treat the area. Then scrub the stain with a brush and rinse thoroughly with clean water.
Cleaning concrete with muriatic acid can be a highly effective solution if used correctly, providing ultra-bright white concrete and removal of many types of stains. In one application, you can remove rust stains, oil stains, algae, and paint splatter with a quick chemical application followed by pressure washing.
Most stains on concrete floors can be removed quickly and easily, but a lot depends on how old the stain is and how porous the concrete surface is. Rust, oil, grease, paint or glue stains each have a recommended stain removal technique.
In fact, vinegar removes mold from concrete better than bleach. Bleach will only remove the top layer of mold, causing the mold to return.
Use a detergent such as Dawn or Ajax dishwashing liquid mixed with water to brighten a concrete patio that hasn't been cleaned in a while. Just as you would regularly vacuum the floor and dust your furniture inside your house, you should keep your patio clean so it's ready at a moment's notice to entertain.
The Liquid peroxide cleans, refreshes, and brightens concrete, tile, and grout without leaving watermarks or residue in contrast to other cleaning chemicals. Powdered peroxide-based formulas are generally high-performance alkaline, tile and grout cleaners and degreasers that are made for use on heavy-duty concrete.
As a gentler cleaner, bleach can't harm concrete's durable material. Aside from being an effective cleaner and stain remover, it also acts as a disinfectant to the concrete surface.
Acid Staining
Acid stains are a reactive coloring process that penetrates into the porous concrete surface. This is probably the most permanent of all coloring options but is usually limited to eight colors.
A few of your options include using: Baking soda and hydrogen peroxide: Make a paste out of both ingredients, apply some to the stain, then scrub with firm-bristled brush. If it doesn't work right away, apply more of the paste and this time, let it sit for 30 minutes before scrubbing.
Spray a mixture of hot water and oxygen bleach onto the concrete. Follow the mixing instructions on the oxygen bleach for best results. The oxygen bleach helps whiten the concrete and is not as toxic as chlorine bleach.
You can use Simple Green Oxy Solve Concrete and Driveway Cleaner to clean a concrete patio with or without a pressure washer. It removes oil, grease, grime and most stains and discolorations. Its biodegradable formula is safe for lawns and pets.
Whether your patio is sealed concrete or cement, or even sealed concrete pavers, a bleach and water solution makes it easy to clean away built up soil, stains from leaves and pollen, mold, mildew and algae.
Vinegar and Baking Soda
Simply fill a spray bottle with equal parts water and vinegar (or water and baking soda), and add a little bit of liquid dish detergent. Spray the mixture on your concrete surface and let it sit for about 30 minutes. Then scrub and rinse your concrete.
OxiClean is a powerful concrete cleaner that works well on various materials, including pavement and grout.
OxiClean Outdoor Multipurpose Ready to Use - Cleaning Supplies - Cleaning Products - Cleaner for Concrete, Vinyl, Grill, Patio Furniture - Degreaser for Cement and Brick (1 Gallon)
A power washer is the easiest way to clean concrete outdoors. You should be able to blast away dirt, mildew and grime in an afternoon. Rent one and read the instructions on how to use the machine before you start the project. Spray the patio surface with a detergent and use a stiff brush to scrub it into the concrete.
For most concrete floors, you can use a mixture of flour and hydrogen peroxide or water and trisodium phosphate. But for stamped concrete floors or polished concrete floors, you'll want to use a gentler solution. If your indoor concrete flooring is stamped, use a mop and mix water and a mild cleaner in a bucket.
Although concrete stain is permanent and won't flake off like paint, it penetrates only the top layer of the concrete surface and will eventually wear away as the surface is worn by traffic or weather exposure.
Cars and lawn equipment can leave unsightly oil and grease stains. But with power washing, homeowners can remove these stains from the garage, concrete driveway, and walkway. You will need a degreasing detergent and a power washer that delivers at least 1700 psi.
Use Bleach
But that's not all; chlorine bleach can also be used for cleaning the concrete driveway. Of course, you should dilute it with equal parts of water or a 1:1 ratio. With the mixture ready, spray it on the driveway, allowing it to sit for 10 minutes. Then, use a stiff brush before rinsing with clean water.