Knoxville Market Square is reader-supported. When you buy via the links on our site, we may earn an affiliate commission at no cost to you.

How to Clean Unsealed Concrete Floors

how to clean unsealed concrete floors

Once relegated to garages, basements, and sidewalks, unsealed concrete floors have now found their way indoors. People who want to take advantage of its durability and easy-care properties are now unsealed concrete for making their countertops and sophisticated floors look stylish.

However, while unsealed concrete floors aren’t prone to physical damage, the pores existing in the surface do have the ability to absorb liquid and become stained. And as long as you don’t clean them at least once weekly, those temporary stains might well become a permanent nuisance.

Read on if you want to know how you can clean unsealed concrete floors on your own:

YouTube video


Cleaning Unsealed Concrete Floors

Although these floors don’t show any dust in the same way as a polished floor might do, unsealed concrete floors still look better after cleaning. So before you start applying the tips mentioned below, remove anything you can see on the concrete with an upright vacuum or a canister vacuum.

However, if the floor is in an area where there is no electrical connection nearby, you can use a cordless vacuum or a cordless stick vacuum. Even a robot vacuum – provided its specification says that you can use it on rough surfaces – might come handy on such surfaces. Once you cleaned the loose debris, move ahead and tackle the following stains:

Removing Grease Stains

how to clean unsealed concrete
Removing Grease Stains

Sprinkle dry kitty litter or a layer of cornstarch over the stained area. Allow it to remain there for at least 48 hours for the material to completely absorb oil.

In case you have doubts, the reason why it would take so long to remove grease stains is that oil goes very deep into unsealed concrete due to the surface’s porousness. Vacuum away at the end of this period.

Beverage or Food Stains

concrete floor clean
Cleaning Unsealed Concrete Floors

Prepare a mixture containing one quart of water and two tablespoons of dishwashing soap. Once the mixture has become homogenous, dip a stiff brush into it before using the brush to scrub the concrete’s surface.

If you feel that the food stain is way too oily, you can directly pour the mixture over it and scrub later on. As you see no signs of stain after scrubbing, rinse the surface with plain water.

Tire Marks

clean concrete floor
mop unsealed concrete floors

As you might guess, unsealed concrete floors in your garage and basement are more prone to having tire marks. Wet the area containing tire marks and then pour a degreaser over it.

Allow the degreaser to remain at the surface for over four hours (or more). After the completion of this time, scrub the surface with a stiff brush before rinsing it with plain water.

Heavy Rust Stains

cleaning concrete floors
commercial rust remover (containing oxalic acid)

Assuming you haven’t washed your unsealed concrete floor for quite some time, you might have to deal with large and dark stains that won’t go away with the application of distilled white vinegar.

Instead, you might have to use a commercial rust remover (containing oxalic acid) to get rid of them. Once you have it, follow the same procedure which we described for dealing with light rust stains.

Light Rust Stains

If you’re dealing with rust stains that aren’t too visible yet, start by pouring a mixture of distilled white vinegar over the stained area and let it remain there for at least half an hour.

Once the time is over, use a stiff brush to deep scrub the stained area. This step might take some time if the signs of rust are on a wide expanse of area. Finish up by rinsing the surface with plain water.

Light Mildew Stains

how to clean a concrete floor
scrub the surface with a stiff brush

Wear rubber gloves and prepare a mixture containing one quart-water, two tablespoons powdered laundry detergent, and two tablespoons trisodium phosphate (TSP).

Once you have prepared this mixture, pour it over the area containing light mildew stains. Follow up by scrubbing with a stiff brush before rinsing the entire area with plain water.

Heavy Mildew Stains

After taking the necessary precautions (rubber gloves, protective clothing), prepare a light solution of chlorine bleach and water. Don’t add more than 1 cup of bleach in 1 gallon of water.

Pour the resulting mixture over the unsealed concrete floor, and then scrub vigorously or else the stains might not go away. Once the stains have come off, rinse them off with plain water.

Safety Note: When preparing solutions for mildew stains, make sure that you’ve worn rubber gloves, protective clothing and are operating in a well-ventilated environment.


When dealing with concrete floors, make sure you’re aware of the type you’re dealing with. For instance, while most of us are aware of what differentiates unsealed concrete floors from their sealed counterparts, we cannot tell a stained floor from an unsealed one.

Once you have made sure that it is an unsealed concrete floor that you’re dealing with, apply the above-mentioned tips to restore it to its past glory. Also, while you won’t be dealing with chemicals all the time, we still recommend that you use the necessary safety precautions to be, you know, on the safe side.

Looking forward to hearing how our tips helped you out!

Scroll to Top