- Clear all the clutter off the floor, leaving the surface free for cleaning.
- Sweep all the dirt away.
- Scrub with a concrete degreaser and deck brush.
- Use a mop or wet vac to remove the residue.
- Spot treat salt, oil, and rust stains.
- Rinse liberally.
Read more to learn each step - how to clean (and how to not). We'll cover the best products and solutions for every kind of stain. And what about pressure washers? Are they safe for garage floors? The answer is - sometimes. Keep reading to find out just when those times are.
The Initial Scrubbing
First, clean the clutter and sweep the floor. When the surface is open and ready for cleaning, use a concrete degreaser and a deck brush to scrub. Don't use a push broom - it's not as good for cleaning. A simple cleaning solution is 1/3 cup of Tide detergent for a gallon of warm water. However, a cleaner made for concrete like this one is more effective.
Can You Pressure Wash A Garage Floor?
You might notice that many concrete cleaners specify that they're for use in a pressure washer. So can't you skip the mop and get out the pressure washer?
Well, if you're trying to clean the floor, you can. Using a pressure washer to rinse the floor is very effective if it's dirt. However, it doesn't work quite as well when you're dealing with salt stains. A pressure washer can force the salt down into the concrete. The floor appears clean, and you're satisfied - for a while. Then, when it dries, that salt works its way back to the surface, leaving you stuck starting all over.
What you need to do, instead, is remove the salty/dirty residue from the floor with a mop or wet vac. Once that contaminated water is pulled aside, you can rinse the floor however you like.
If the floor is painted, you might want advice on How to Remove Paint From Concrete? [5 Simple Steps]
How To Remove Rust Stains From Concrete?
If the rust spots are relatively small, cleaning with vinegar can help. Let it sit for 5-10 minutes, scrub, and rinse. If you need something stronger, try oxalic acid. Be sure to follow all directions and safety instructions. You can also try commercial products such as this one:
How To Remove Oil and Grease From Concrete?
First, wet the stain. Next, apply your concrete degreaser directly to the stain and scrub. Let it sit for about 10 minutes, scrub again, and rinse. Don't let the mixture dry until you've rinsed it. Any dirt that you bring to the surface will soak back into the concrete if you give it enough time to dry.
Alternatively, use a powdered laundry detergent such as Tide. Apply some powder directly to the wet stain, and add enough water to make a paste. Scrub. Once again, don't let it dry out. The detergent is drawing the oil out of the pores in the concrete. If it dries, it will go right back in. Keep it moist until you rinse all the contaminants away.
If you have really old stains and need something extra tough, you might have to use a technique called bio-remediation. This takes a while - it won't work if you need the floor clean by tomorrow. But if you have time, there are products you can apply that slowly break down the oil. As the product "eats" through the oil stain, you can add more until you've achieved the desired result. Just keep in mind, it might take as long as a week.
How To Remove Efflorescence From Concrete?
Scrubbing with a concrete cleaner and a deck brush may be enough to remove efflorescence from concrete. For stubborn stains, try using vinegar.
Avoid using hot water, as this can push salt further into the concrete. Similarly, using a pressure washer can push salt further into the pores of the concrete. Ideally, remove all residue with a mop or a wet vac. If that's a little too hands-on for you, at least use the pressure washer or hose on a low setting when rinsing.
What To Do If Stains Are Really Bad?
If nothing else has worked, there are two last-ditch efforts. You can use a floor buffer or "strip" the concrete's surface with muriatic acid.
You'll still need a cleaning solution for a floor buffer like one of the ones listed above. Be sure to keep the floor wet while you work - any dirt will resettle into the floor if you let it dry out. Don't forget to specify with the rental company that it's for concrete. You'll want to be sure that you get a buffer with a special nylon scrubbing head appropriate for the concrete surface.
Using an acid cleaner such as muriatic acid will actually etch the concrete's surface. It will remove stains - and everything else. This method requires safety equipment such as goggles and gloves. Only use this option if you're confident in your ability to handle hazardous materials.
If you're going to clean the floor with acid, you should typically do the entire surface. It can change the look or color of the floor slightly. As a result, doing the floor in small areas will tend to look patchy. Mix a ratio of 10 parts water for 1 part acid to begin, increasing as needed. Be sure to always pour acid into the water - the other way can cause a dangerous reaction that splashes into your face or skin.
A ratio of 3:1 is typical for true acid etching. Use this ratio instead if you plan on sealing the concrete next. Sealing will help prevent future damage and stains.
Is Sealing Concrete Necessary?
Exterior concrete should be sealed, as cycles of freezing and thawing can destroy the concrete. Inside, in the garage, it is more an issue of stain and chemical repellence. It may not be necessary, but it keeps the surface of the concrete clean and attractive. It can reduce the amount of elbow grease and the frequency of cleaning. Read more about sealing concrete here.
Can You Use Clorox On Concrete?
There's no harm in using Clorox on concrete, though it's generally not the most effective cleaner. If you're dealing with pet urine, mold, or mildew, Clorox might be an appropriate choice. And if the concrete is unstained and in need of general surface clean, Clorox works.
More commonly, concrete is facing problems from stains like grease and oil - Clorox has very little to offer here. However, you can always use Clorox for the initial cleaning. It will clean the surface, leaving you ready for a more intense degreasing effort next.
After winter, salt and deicers can make a mess of your concrete floor. In addition, spills from oils, grease, and rust stains can also be tough to remove. Concrete is naturally porous, and eliminating contaminants takes a lot of elbow grease.
Use a concrete degreaser or a solution of diluted Tide to clean the floor. Remove the dirty water with a mop, then rinse. Don't use a pressure washer until the surface dirt is removed, as the pressure washer can push the dirt deeper into the concrete's pores.
Treat tough stains with vinegar, a more concentrated cleaning solution, or special commercial products made for concrete. For really tough jobs, consider a floor buffer or muriatic acid. Acid solutions can be used to clean the floor and also prep the floor for sealing. While interior concrete doesn't need to be sealed, it can save you from future cleaning hassles.