If you’ve invested in a beautiful concrete polishing job for your showroom, school lobby, coffee shop, or industrial facility, you want to keep your floor looking great. In addition to regular cleaning and maintenance, that means preventing your polished concrete floor from becoming stained or discolored.
Be aware that removing stains from polished concrete takes a bit more care than for untreated concrete applications. Some of the general advice you’ll come across for removing concrete stains can actually damage your floors, so be careful!
First Steps for Removing a Stain from Polished Concrete
It’s easier to wipe up a spill than to treat a deep-set stain. If you notice oil, grease, or other liquids on your floor, follow these steps first before reaching for a chemical cleaner:
- Clean spills right away so they don’t soak in. Concrete is porous, so the longer a stain sits, the deeper it can set and the harder it will be to remove.
- Blot, don’t scrub. Use a cloth to absorb as much of the liquid as possible. The goal is to draw it out of the floor. Scrubbing the spill or stain at this point may inadvertently drive it in deeper.
- Avoid abrasive tools and harsh scrubbing. Once the initial spill has been removed, a little elbow grease is all right. But don’t get too aggressive with your scrubbing tool, or you may scratch your floor’s polished surface or even remove patches of your sealant.
- Consider using a poultice. Greases and oils can sometimes be drawn up and out of a concrete floor by using an absorbent material such as kitty litter, sawdust, dry clay, pool filter sand, or baking soda. This can be applied dry and left to sit for a couple of days, or it can be mixed with a bit of water or a neutral degreaser to make a paste. If you opt for the wet poultice, cover it by taping plastic wrap or a tarp over it and leave it overnight.
Which Stain Removers Can I Use on Polished Concrete?
Some chemical cleaners are safe to use on decorative concrete floors, while others can leave permanent marks that are worse than the stains they’re meant to treat. The same goes for household hacks, or repurposed solutions, like cola. In general, it’s best to use neutral solutions over those with an acidic or alkaline base. See the table below for a quick reference guide on which cleaners are safe.
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Stain Removers and Polished Concrete |
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Safe for Polished Concrete |
Damaging to Polished Concrete (Do Not Use) |
Sometimes Useful When Applied with Caution |
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Avoid Acidic Cleaners
The acids in products such as vinegar, citrus juices, and CLRs (calcium, lime and rust removers) react chemically with the calcium hydroxide in your concrete, in a process called acid etching. Etching can leave permanent white, chalky marks.
Read the ingredients on all your floor cleaning products to ensure there’s no vinegar, citrus, or other acid included. (A picture of an orange or lemon on the bottle is a clear warning sign.)
Be Cautious with Alkaline (Basic) Cleaners
Alkaline cleaners—such as ammonia-based products and many detergents—can also damage a polished concrete floor if used incorrectly. They’re not quite as reactive as acidic cleaners, but they can still interfere with sealants or leave residues that will discolor or dull the floor over time.
For especially tough stains, an alkaline product can occasionally be used with caution.
- Dawn dish soap (diluted) can be used to break down greasy stains but should not be used regularly.
- Bleach can sometimes be used in small amounts to handle stubborn stains such as wine or oil. Cover the spot briefly with a cloth or cotton ball dipped in bleach and remove it within 10 minutes. A small amount of bleach may also be sprayed onto the surface and scrubbed, but it should be rinsed off promptly.
If your floor has a decorative color stain applied, test bleach or detergent in an inconspicuous place first to be sure it won’t react.
PH-Neutral Cleaners
The safest option for removing stains from your floor is a concrete cleaner that is neither acidic or alkaline. You can find several brands of concrete cleaners on the market. Be sure to choose one labeled “PH neutral.”
Read the usage instructions carefully, and be sure to dilute the product as directed before applying it to the floor. When you’ve finished, rinse off the product and use a dry cloth to remove any standing water from the surface.
Some gentle de-greasers can also be used to break up oil or grease stains, but read the packaging carefully. Avoid anything that’s citrus-based or “extra-strength.”
When in doubt, test a new product on an inconspicuous corner of the floor before applying it to a visually prominent area.
Be Careful with Solvents and Other Products
Be especially cautious with solvents if your floor has a sealant, densifier, or colored stain applied.
- Acetone, while PH-neutral, can be used to break down tough stains—but it will also eat through a protective floor coating and possibly interfere with certain colorants.
- Though sometimes touted as a great solution for driveway stains, WD-40 (and similar products) may be too strong for your polished concrete floor, so proceed with caution.
Preserve Your Polished Concrete
While polished concrete takes a bit more caution to clean than untreated floors, it’s still a durable and relatively low-maintenance solution when compared to other flooring options. We hope these tips help you keep your polished concrete looking great for years to come.
If your polished concrete floor needs refurbishing, talk to one of our specialists today. The team at CPC Floor Coatings has more than 40 years of experience treating commercial concrete floors throughout the Southeast. Give us a call at (864) 855-0600 or contact us online.