HOW TO CLEAN CONCRETE

If you're trying to figure out how to clean your concrete, you've found the right page.
Cleaning concrete isn't an exact science. What I mean is, it depends on the kind of substance you're trying to remove from the concrete.
Is it an organic material like dirt or leaf residue?
Or is it an in-organic material like oil or grease?
Or.... is it dog or cat urine?
All these have different methods if you want to achieve the best results and get your concrete clean again.
Having been in the concrete business for over 30 years, I'll share with you what's worked best for me when I'm cleaning concrete for my customers.

Concrete work OKC area

CLEANING EXTERIOR CONCRETEMy best method for cleaning concrete is with a pressure washer. A pressure washer will remove most, if not ALL, of the dirt and mold related issues when it comes to getting your concrete clean again.

This method includes cleaning concrete driveways, concrete patios, pool decks, concrete stairs, stamped concrete, sidewalks, and walkways. It even includes cleaning concrete walls and retaining walls.
If you've got a pool deck that's discolored and dirty, a good pressure washing will remove the dirt, mold, mildew, leaves, and bird droppings, making it look like new again. Same goes for a dirty concrete driveway.
Having the right pressure washer and cleaning accessories will make the job even easier.
WHAT TOOLS YOU'LL NEED
Most pressure washers will do just fine. I like ones like this with at least 3000 psi pressure. It gives you just enough power without being too big and heavy.

Along with the pressure washer you'll want to get one of these surface cleaners to attach to the wand. This will cut your cleaning time in half. These work great for removing dirt, mold, and mildew. It also does a good job of containing the water so everything else doesn't get wet.

FOR CLEANING SMALL AREAS OR SPOTSIf all you have is a small area to clean or just a few spots then you probably don't need a pressure washer.

I use both a stiff bristle scrub brush and a drill brush. Both these brushes along with a cleaning agent are great for small areas.
Just rinse the area with a garden hose, mix some cleaning agent in a bucket and apply it to the dirty concrete.Scrub the area with the scrub brush or the drill brush and rinse again. Repeat as many times as you need to. Your concrete will be cleaner.
If the area is just not getting as clean as you like with soap and water, check out some of my other suggestions below.

SOME CLEANING DETERGENTS THAT WORK
If after, or during pressure washing you don't think the concrete is getting as clean as you like, then try some Dawn dish detergent or Simple Green.
Either one of these usually does the job for me.
Mix two tablespoons in a 5 gallon bucket of water and scrub the dampened concrete.
Soaps like these even work good to remove lightly stained areas from oil and grease. The soap will re-emulsify the oil and then you can remove it by rinsing it away.
Once you're done scrubbing, pressure wash the area again and rinse off any soapy residue. This method has worked the best for us in most cases.
NATURAL REMEDIES YOU CAN TRY
I've used vinegar and water to clean concrete. Mix 1 part vinegar to 1 part water for a fairly strong cleaning solution.
I've also used lemon juice and water. You can either buy lemon juice and mix 16 oz per gallon or you can just squeeze some lemons into a glass of water for small areas to concrete to clean.
I've also used baking soda, 1/2 cup to 1 gallon of water is a good mixture to try at first.
You can also mix 2 Cups of baking soda with 1 Cup of Bleach in a gallon of water for a stronger solution.
Pour this on your concrete and scrub it into the surface. It will remove dirt, grime, mold, mildew and some staining.
All these cleaning solutions have worked for me at one time or another on various types of concrete.
Just be aware that vinegar and lemon juice are acidic, you don't want to use too strong of a solution or it could etch the concrete.
This mostly applies to polished concrete, concrete countertops, or stained concrete.
If you don't want to mix your own solution at home, there is a good vinegar based cleaner as an alternative that's already mixed with water.
NOTE: Always try cleaning in an inconspicuous area first if you can. See how the cleaning solution will react with your concrete before you try it in a large area.