What Causes Molds On Cement? How to Remove Mold From Concrete?

Helen Skeates
Helen Skeates
13 min read

Molds are a common problem in any environment, indoors or out, therefore surely it is important to learn effective methods for removing mold from cement. So long as you’re investigating the issue, let’s check out its root causes as well.

Bread, meat, and sugary meals, as well as damp, dark places such under the sink, are prime locations for mold growth. In case you were wondering, the answer is yes, they can be found almost anywhere.

Molds are fungi, and like other fungi, they need a conducive setting in which to multiply. All these conditions are certainly present in your home if these molds have found their way to some cement in your house and are establishing colonies there.

How to Remove Mold From Concrete: Options

1. Liquid Laundry Detergent and Household Bleach

Bleach is a typical and successful method for eradicating black or green mold from concrete. The mold on concrete can be removed and prevented from recurring by using bleach, which works by killing it at its source.

How to Remove Mold From Concrete - Cleaning Tips - Concrete Network

It is best to start cleaning mold off concrete by hosing down the area and eliminating as much black mold as possible. Indoors, you can use a sponge to remove mold from the concrete. One can also successfully remove the mold from the concrete with a scraper.

Even though these techniques work, removing the mold by hand will not get rid of the root because it is embedded in the porous concrete. If the mold’s foundation is still solid, it will simply return.

Penetrating cleansers are needed to eliminate mold growth beneath the concrete’s surface. Bleach may be a good mold killer, but it’s not the best choice for soaking concrete due to its high surface tension. If you must use soap, use laundry detergent instead.

Combine one cup of laundry detergent and one gallon of water to make a cleaning solution. Apply the solution to the floor with a sponge or a brush. Detergent will penetrate the concrete’s pores and kill the black mold there.

Scrubbing the concrete with a brush will help the solution reach the mold deeper in the slab and will also help get rid of the mold’s roots. The concrete should be washed down with clean water once you’re done. A hose can be used if the task is performed outside. Indoors, a mop should be used.

If mold still exists, you will need to repeat the treatment. Use a fan to dry the concrete until it is no longer damp.

A bleach solution can then be made by combining one cup of bleach with one gallon of water. Apply the solution to the concrete using a spray bottle and let it dry. As a barrier, the bleach will stop any mold spores from penetrating and taking hold.

2. White Vinegar

White vinegar can be used as a substitute for bleach if you don’t have any on hand or if you’d like a non-toxic cleaner to get rid of black mold. White vinegar’s acidity can eradicate both black and green mold. To kill mold, use vinegar in the same way you would chlorine bleach.

Put three parts water and one part white vinegar into a container and stir until you get a solution. The solution is mopped on, and then the floor is scrubbed thoroughly. The solution needs to seep deep into the concrete to reach the black mold spores at their source.

To remove stubborn mold stains from concrete, soak the area first. A hose can be used to flush out the mold-killing vinegar solution and any flakes that may have accumulated. If mold is still present after applying the solution, repeat the process.

After the area is dry, spray it with the bleach and water mixture to kill any mold that may have been present.

3. Pressure Washer

One of the best tools for eliminating mold from concrete is a pressure washer. It’s superior to a mop or scrub in terms of efficiency, therefore it’s the best choice for treating expansive spaces like a wall or an entire driveway.

High-pressure water can effectively replace manual labor for cleaning up moldy areas. Make use of a pressure washer with a PSI of 1,500 or higher. To clean concrete without damaging it, this generates sufficient force.

Water alone won’t cut it when using a pressure washer. A mold and mildew concentrate poured into the pressure washer’s tank will do the trick.

Nozzles on pressure washers come in a variety of shapes and sizes, allowing for a wide range of pressure to be applied to the home. Keep in mind that high-pressure nozzles (usually colored red) aren’t designed to be used with detergents, so refrain from using them if you want to avoid damaging the concrete surface.

Use a nozzle with a low pressure, instead. Using a pressure washer, spray the concrete surface from bottom to top (if it’s a wall) and back and forth (if it’s a floor) to remove the mold. By using this technique, surface streaking is avoided.

After allowing the cleaner to sit for 10 minutes, rinse the concrete with a high-pressure nozzle featuring a broad fan. Wave the same way to remove the mold remover and cleanser from the surface.

4. Zep

You will need a concentration for your pressure washer if you intend to clean concrete with it. In order to effectively remove mold from concrete, we recommend using the Zep Concrete Pressure Wash.

This product’s strength is in its ability to clean a wide variety of surfaces. In addition to eliminating the mold in your driveway, the degreaser component of this product will help get rid of the grease and grime that has accumulated there. Because of this, it is a fantastic choice for any outside space, including roads, walkways, and patios.

Just mix 6 ounces of Zep with 1 gallon of water. You can use up to 25 ounces per gallon for stubborn stains. Use a cleaning applicator to apply the solution, let it sit for 10 minutes, and then rinse it off with a spray nozzle.

Can mold grow on concrete? – JK Industries, Inc.

Use a brush to scrub the product into the concrete after applying it to remove stubborn mold spots. It is not only safe for concrete, but also asphalt, brick, and stone. One-gallon containers are available for purchasing Zep.

5. RMR-141

Two active components, ammonia and chlorine, make RMR-141 effective against mold and mildew.

RMR-141 can eliminate 99.9 percent of germs and is packaged in an easy-to-use spray can. In-home concrete surfaces plagued by mold can benefit greatly from this application procedure. Furthermore, the Environmental Protection Agency has approved its usage for mold removal in enclosed spaces.

The amount of toxic gases it emits is negligible, and unlike other cleansers, RMR-141 leaves behind a pleasant citrus aroma. Given these characteristics, it is a great choice for eliminating mold growth inside.

When cleaning a concrete surface, spray on RMR-141, wait for it to soak in, and then wipe clean. The positive charge of RMR-141’s composition makes it more effective at sticking to and killing germs. In order to get the best possible results from the cleaning process, rinsing with a chlorine solution is highly recommended.

RMR-141 is applied using a handheld sprayer, thus it’s suitable for tiny areas like a basement floor or wall or isolated sections of a patio or driveway. There are 128-ounce bottles of RMR-141 available.

6. Simple Green

Many pressure washer cleansers, while effective against mold, may be devastating to the grass, plants, and shrubs in and around a home. The Simple Green recipe is safe for use around shrubs and grass. Products by Simple Green are non-toxic, meaning they are safe to use around kids and pets and won’t hurt the earth.

As a result, it can be used as a suitable replacement for chlorine bleach for cleaning concrete surfaces in close proximity to plants and flowers.

A concrete patio, walkway, or driveway can be thoroughly cleaned with Simple Green, just as one can with any other concrete cleaning solution. This is because it contains a degreaser that effectively eliminates mold and eliminates oil stains from concrete.

One part cleaner to 10 parts water is the recommended ratio for use. Pressure-wash the concrete or manually apply with a brush or mop to wet it. Use a brush to scrub the product into the concrete, especially for stubborn mold spots.

Ten minutes after applying the cleanser, rinse with a hose or pressure washer. A single gallon of Simple Green can be purchased from stores.

7. Mold Armor

Thanks to this tool, there is no need to hassle with preparing cleaning solutions or forking over cash to rent a pricey pressure washer for removing mold from outdoor spaces. Connect Mold Armor to your garden hose and spray it on your sidewalk, patio, or driveway.

To eliminate mold from the foundation up, Mold Armor injects a chlorine-based solution into the concrete. The cleaning should be applied, and then the mold should be scrubbed away with a scrubber before being rinsed with a sprayer. Because it won’t kill grass or shrubs, this product can be used anywhere in the yard.

Mold Armor is not just great for cleaning concrete, but also for cleaning siding, brick, wood, and stucco. Mold Armor is sold in a two-bottle, 64-ounce set that can disinfect an area 4,500 square feet in size.

What causes molds on cement?

Mold can form on concrete for the same reasons it can form on any other material: water and air circulation at the surface, and sometimes some food source beneath. Molds may survive on a variety of foods, including algae, moisture, and even salt, but they would have a hard time eating inorganic concrete.

You can be more successful in your efforts to eliminate these fungi if you learn not just what creates mold within your home, but also what causes it outside.

Can Mold Grow on Concrete?

Yes, mold can colonize concrete. This happens frequently in the shaded parts of patios, steps, and driveways that become wet yet take a long time to dry out.

The north face of a wall, concrete in shady spots, and patio flooring all qualify. Mildew and mold thrive in these humid, dark environments.

Condensation puddles, leaking pipes, and water seeping in through the basement’s foundation are all indoor conditions favorable to mold growth.

Mold thrives on concrete because of the material’s porous nature. Hot and humid climates are conducive for the growth of mold on concrete.

Spots of black or green color appear when mold grows on concrete. Although white mold is possible, it is often misidentified as efflorescence, a salt buildup on concrete created when water evaporates into the porous surface of the concrete, leaving behind the salt.

Is Mold on Concrete Dangerous?

While outside mold growth can be ugly, inside mold growth on concrete surfaces poses a serious health risk. Because of the danger it poses to human health, black mold should be removed from the home as soon as it is discovered.

How to Remove Mold from Concrete Floors | DoItYourself.com

Allergies to black mold can be made worse, asthma attacks triggered, and the eyes, nose, and throat irritated. In addition, if it is allowed to spread, it can destroy a building if it eats through the wood supporting the concrete.

Protective gear should be worn when eliminating mold from an indoor environment. When mold growth is extensive inside a building, it’s necessary to hire experts to do costly mold mitigation work.

Is Black Mold on Concrete Dangerous?

Contaminated concrete surfaces are a real health risk. Some people develop asthma or allergies after being exposed to excessive concentrations of black mold. Itching, redness, or a burning sensation in the eyes, nose, skin, lungs, throat, or skin can occur even in people who are not allergic to mold. Mold allergies manifest in a variety of ways in susceptible individuals, including nasal congestion, itchy eyes, and continuous sneezing. One’s life may be at danger if they have a severe allergy to mold and experience symptoms like shortness of breath. A person with asthma who has also developed a mold allergy may have an asthma attack if exposed to mold.

What causes black mold on concrete?

There are many potential conditions that favor mold growth on concrete. Black mold, like all other varieties of mold, thrives in damp, dark places. Black mold thrives in damp environments like those created by dripping windows, roofs, pipes, and water storage tanks. Black mold spores can travel great distances by air currents, animals, and water. Black mold will grow rapidly on a damp concrete floor. A small black mold patch can swiftly spread and become a large one. That implies black mold could start growing on your concrete surface in no time.

When black mold appears on concrete in a basement, it could be the result of a water leak from the outdoors or a plumbing problem. Mold growth is another common issue in homes with excessive humidity. Mildew typically forms on damp outdoor concrete like a patio if it is not allowed to dry thoroughly. That’s the way concrete usually looks when it’s been tinted properly.

Can mold grow on concrete?

As long as there is water present, concrete will support mold growth. Mold can still grow in concrete even when there isn’t enough food to sustain it if the surface is damp enough. Mold can flourish in environments where dust and other waste have settled, such as on concrete surfaces. Keeping concrete floors and walls dry and clean will help prevent mold from spreading there.


Having learned the proper method for eliminating mold from concrete, you can now go about eliminating any mold colonies that may have taken up residence in the crevices of your home’s concrete walls.

Helen Skeates

Helen Skeates

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