How To Clean Your Concrete Garage Floor: Step by Step Guide

By
Harold K. Hardesty
Harold is a Flooring Specialist at TheHouseWire, educating people on the flooring by writing guides about the topic. He is a well-seasoned flooring specialist with experience in the industry for nine years.
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Updated April 13, 2022

Check out this “concrete” way to easily clean your garage floor!

Check out this “concrete” way to easily clean your garage floor!

Garage Concrete Floor
Do you have oil stains on your concrete garage floor? Or dried paint on your basement floor?

Whether you have polished concrete or concrete without a floor coating, cleaning garage floors can be tricky.

The truth is: It’s often difficult to get all the marks and grease stains off.

But don’t worry. With this article, you can clean up any messes from your car or spilled paint on your clean garage floor.

So, keep reading for useful tips on how to clean concrete floors. In no time, your basement, garage, or workshop will sparkle.

What You’ll Need

Instructions

01 Remove Dust and Debris

First, you need to get all the dirt particles off your floor. To do this, you can use a push broom, a vacuum cleaner, or a shop vac.

For big clumps or piles of dirt, it’s easy to use a broom with stiff bristles. But for finer particles, it’s a good idea to use a vacuum or shop vac.

These appliances will remove small bits of dust and dirt that might not come up with a dustpan. Also, they can pull debris out of crevices in the floor, as well as remove spider webs.

02 Use a Garage Floor Cleaner

Next, follow the instructions on your trisodium phosphate or commercial cleaner for dilution. Or, if you are using dish soap, mix that with some water.

Then, mop your floor with the cleaning solution.

For this, a sponge mop works really well. This is because they’re designed for uneven areas, like concrete surfaces.

But if you prefer to use a scrub brush – or even a floor buffer, that will work fine too!

Warning

While trisodium phosphate is an effective cleaner, it’s also bad for the environment. For example, when it enters the water system, it can cause eutrophication in lakes and rivers.

Eutrophication happens when too many minerals or nutrients enter a water system. And this can cause events like algae blooms.

In turn, this can destroy the entire ecosystem of the waterway.

So, instead of using this cleaning solution, try using bleach, which is safer for the environment. According to the CDC, you should dilute 1 cup of bleach in 5 gallons of water (1).

Or, if you’d like to make your own concrete cleaning solution.

03 Rinse

When you’ve finished scrubbing, it’s time to rinse! And don’t skip this step because you want to get all the chemical residue off your concrete floor.

For this step, you can use a squeegee and bucket. But if you have a power jet wand, it will make your job even easier because of the pressure of the water.

04 Let Air Dry

Finally, let your floor dry. This is especially important if you have an unsealed concrete floor.

Removing Stains From Your Garage Floor

Before you start cleaning, make sure you understand how your cleaning process works. In other words, some techniques will clean garage floors by removing the stained concrete.

For instance, grinding or abrasive blasting will remove the top layer of the concrete in order to remove the stain. As well, chemicals like acids will dissolve the concrete.

In this case, the heavy duty cleaning method can change the color and texture of your garage floor. So, make sure you understand the risks.

Also, it’s a good idea to test your preferred method in a hidden area of the room. That way, you can see if it will negatively affect your concrete before you clean the entire floor.

Instead of grinding or other abrasive solutions, you can pressure wash your floor. If you use a pressure washer, both the high pressure nozzle and added detergents can remove many common stains.

And try these methods for some common stains:

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Tire Marks

The easiest way to remove tire or skid marks is through pressure washing. But if that doesn’t work, try buying a cleaning solution at the hardware store that’s specifically made for rubber removal.

If you already have a brake-cleaning solution, you can try that as well.

But regardless of what you use, always test the product in an inconspicuous area first. And when you’re done, make sure you rinse off all the chemicals.

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Oil and Grease Stains

Oil spills are some of the trickiest stains to remove because grease soaks into concrete garage floors quite quickly.

So, if you notice oil and grease stains on your floor, immediately stop them from spreading. To do this, put a circle of absorbent material around the spots.

For this, you can use dirt, sand, cat litter, or sawdust.

Next, use more absorbent materials to soak up as much grease as possible. In other words, use more cat litter, absorbent powder, paper towels, or rags to pick up the excess oil.

Then, put an engine degreaser or a grease-specific cleaner on the spot. When you’ve finished, rinse the spot completely with water.

On the other hand, you can make your own cleaner with lime and turpentine to dissolve oil. For this, combine 2 parts mineral turpentine with 1 part lime.

This will form a paste, and then you can spread a 5mm layer on top of the spot. When you do this, make sure to cover an extra 50-100mm around the stain with the mixture.

Next, lay a piece of plastic sheeting on top and let the paste sit for 24 hours. Afterward, uncover the oil stain and scrape off the paste.

To rinse, dilute liquid or powdered laundry detergent in warm water, and scrub the spot. Then rinse once more with clean water to remove the laundry detergent.

Sometimes, it can take a couple of applications to remove oil stains. So, repeat this process within the next day or two to remove tough stains or oil that rises to the surface.

You can also use a cleaner like sugar soap that’s made with phosphate. But this usually only works for light stains.

So, if you have tough stains on your garage floor, you might want to try the other method.

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Rust Stains

It can be tricky to remove rust stains, but it’s not impossible.

The first step to removing rust stains is to scrub them with a stiff brush. Then, choose a cleaner made specifically for rust stains, and spread that on the mark.

Or, if you’d like to make your own cleaner, you can use a pantry staple, such as pure white vinegar or lemon juice. However, these products are acids, and they can damage your floor.

Because cement is alkaline, when you put an acid on top, the two substances react with one another and dissolve the cement.

Therefore, you must dilute your acid. For general cleaning, mix 1 part vinegar or lemon juice with 10-20 parts water.

And make sure you wash the acid off thoroughly when you’re done so that it doesn’t continue dissolving your concrete garage floors.

If your rust stain is really deep, you might need to use a poultice. For this step, add a sodium citrate solution (1 part sodium citrate to 6 parts warm water) to your poultice and cover the stain.

You can get sodium citrate (also called trisodium citrate) from chemical suppliers.

Once the poultice has dried, you can scrape it off your garage floor and scrub the stain with soapy warm water. Finally, rinse the area again with clean water.

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Food Stains

For cleaning food stains off your garage floor, the best solution is dishwashing liquid.

If your stain is oily or greasy, pour the soap directly on the spot without diluting it. But if not, then mix the soap with some water and scrub the spot with a brush.

Finally, rinse the soap off.

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Efflorescence Stains

When salt deposits form on the surface of concrete garage floors, it’s called efflorescence. And how you clean these marks will depend on whether or not they will dissolve in water.

If the deposits are soluble, the best way to remove them is with a stiff broom or brush. And it’s best if you remove them as soon as they appear.

Try to remove soluble stains when dry, either with the brush, broom, or a vacuum cleaner. However, you can scrub them with water if that’s not working.

But keep in mind that when you wash them with water, the salts dissolve. And then they can reappear when the water evaporates.

Therefore, it’s more effective to scrub them when dry.

If you have stains on your garage floor that are hard, crusted, white, or scaly, they are insoluble and won’t dissolve in water. To get rid of those, you need to use a hydrochloric acid or muriatic acid solution.

Muriatic acid is a slightly diluted hydrochloric acid that you can buy at your local home improvement store.

To make this cleaner, mix one part muriatic acid with 10-20 parts water. Also, make sure that you wet the stain thoroughly (but not excessively) before applying this mixture.

Then, apply the acid solution and wait for 10-15 minutes.

Finally, rinse off the acid and scrub the spot with clean water. And make sure you rinse at least twice to remove all the acid residue.

As well, be careful when using chemicals, such as hydrochloric acid, as they can cause skin irritation or other side effects.

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Paint Stains

How you remove paint stains from your garage floor depends on whether they are dry or wet.

Dry

First, scrape as much paint as possible off the concrete surface. Next, spread a commercial paint remover over any remaining stain.

Let this sit for 20-30 minutes. Then, scrub the mark to loosen the dried paint.

Finally, clean your garage floor with water to rinse off the chemical.

Wet

First, remove any excess paint with paper towels or a rag. To do this, use a gentle blotting motion.

You should never rub or wipe wet paint when you clean a garage floor because you can make the stain spread deeper into the concrete.

Now, you need to know whether your paint is water-based or oil-based.

If the paint is water-based, then scrub the spot with fine sand or another abrasive powder. Then, rinse the area with water.

However, if the paint is oil-based, you need to wait at least 3 days for it to dry. Then you can use one of the dry methods we described above.

If you try to remove oil-based paint with a remover when it’s still wet, you can end up making the stain spread out farther and deeper into the floor.

Can You Power Wash a Concrete Garage Floor?

Yes, you can use a pressure washer to get your concrete garage floor clean – if you do it right.

Many manufacturers of pressure washers say that you can use their machines on garage floors. However, you have to choose the right setting.

If you pick the wrong one, the force of the jet can damage any coatings on your floor, or the floor itself. So, make sure you read the user manual to choose the correct setting.

On some appliances, you can adjust the angle of the spray so that it is more or less intense. For example, certain models suggest a 0-degree direct spray, while others advise a 25-degree spray for concrete.

But either way, make sure you test the appliance in an inconspicuous spot before cleaning the entire floor with the pressure washer. You don’t want to damage any garage floor coatings or the surface of unsealed concrete.

As well, think about other items in your garage before you start spraying. Since you’re cleaning inside, you could accidentally damage things with the high-pressure jet.

So, make sure you protect items such as electrical outlets, walls, the garage door, vehicles, or other appliances before you begin your work.

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