America’s Leading Water Damage Restoration & Mold Remediation Company.

Damp Solving Water Damage Restoration & Mold Remediation

Call Today

All States Covered


Can Mold Grow On Concrete Surfaces

Home / Blog

Is Concrete Prone To Mold Growth?

Is it possible for mold to grow on concrete? Many people use concrete for their basement, patios, garages, and steps, which are usually cold and humid, making them ideal locations for mold growth. This raises concerns about whether mold can damage our concrete walls, leading to respiratory issues, skin problems, and even structural damage.

So, how does mold affect concrete walls? Can mold grow on concrete? And, most importantly, how can we prevent it from spreading on concrete surfaces?

We’ll cover all of these topics below, so keep reading to learn more.


Is Concrete Prone to Mold Growth? Exploring the Relationship Between Fungi and Concrete Walls.

Absolutely, mold can grow on concrete just like it can grow on any other surface. In order to grow, mold needs three things: oxygen, water, and a food source. While concrete itself is not an organic material and does not provide a direct food source for mold, it can still provide a home for mold to grow.

This is because many organic substances can settle on a concrete surface, including dust, debris, dead skin cells, and hair, which can provide enough nutritional supply for mold to grow and spread. Once mold begins to grow on a concrete surface, it can release acids and enzymes that break down the surface, making it weaker and more porous, and thus more susceptible to further mold growth.

In addition, mold can easily grow on drywall, which is often installed directly on concrete walls. This can cause mold to spread rapidly over a wide area, making it difficult to contain and remove.

Likewise, if there are any organic materials near the concrete, such as wood flooring, window framing, carpets, or rugs, they can also become infected with mold and spread it to the concrete surface.

Therefore, it is crucial to take preventative measures to avoid mold growth on concrete surfaces, such as keeping the area clean and dry, using proper ventilation, and ensuring that organic materials are not in close proximity to the concrete.


Detecting Mold on Concrete: Signs and Symptoms


Identifying mold on concrete can be a challenging and tricky task, especially when dealing with white or light-colored stains. The dark grey color of concrete makes it difficult to spot mold stains, and it can lead to neglecting hidden mold colonies that can harm both your concrete slab and your health.

However, it’s essential to differentiate between mold and efflorescence, which is a powder-like substance that forms on the surface of some construction materials due to moisture carrying minerals and salts within them.

Efflorescence feels hard to the touch, turns into powder easily, and doesn’t grow in size, unlike mold. Spraying water on efflorescence makes all the minerals dissolve and disappear, while water does nothing to mold.

Mold has a musty or earthy smell, and it grows in size over time. If you suspect mold on your concrete, a moisture meter can help you identify it, especially if supported by clear visual indicators.

What Moisture Reading is Typical for Concrete Using a Moisture Meter?

The moisture meter reading on concrete varies depending on the type of meter and the reading scale used. Moisture meters calibrated for concrete should give readings less than 2%, as concrete should ideally be dry and free of dampness. However, if your moisture meter is not calibrated for concrete, you can use the reference scale and compare values to a known dry and mold-free concrete sample. It is important to note that the values obtained from a reference scale are qualitative estimates and not the actual moisture content. By establishing a baseline or reference reading, you can identify whether other concrete slabs are dry or have high moisture content that may promote mold growth.  

As mentioned earlier, a reference scale is an additional reading scale that you can find on most moisture meters. The reference scale allows you to test humidity in materials for which the instrument has no dedicated reading scale.

For example, a wood moisture meter has a reading scale for wood, but it can also have a reference scale that allows testing moisture on drywall, concrete, tile, bricks, etc.

When you use the reference scale, you need to compare the reading you get to a dry reference. A dry reference is a sample of the material you’re testing that you know for sure is dry and free of moisture or mold. The reference scale is calibrated based on the moisture content of this dry reference.

The values you get on a reference scale are just qualitative estimates, not the actual moisture content of the material under test. This is because the reference scale provides you with a measure of how much water is in the material you’re testing compared to the dry reference sample.

For example, if you test a concrete slab and get a reference scale reading of 5%, it means that the moisture level in that slab is 5% higher than the moisture level in your dry reference sample. It doesn’t tell you the actual moisture content of the slab.

Therefore, it’s important to use a dry reference sample when testing moisture levels with the reference scale. This will give you a baseline or reference point that you can use for future checks. If other samples give the same values, then it’s safe to consider them as dry and less likely to have mold. However, if you find higher readings, it’s an indication that there’s more moisture in the material and it may be at risk for mold growth.


How Mold Growth Impacts Concrete: Causes, Effects, and Prevention

As mentioned before, concrete is not immune to the harmful effects of mold growth. When mold colonizes on concrete surfaces and starts consuming organic matter, it produces enzymes and acids that break down the integrity of the material, making it more porous and susceptible to further damage.

This increased porosity can allow more dust, debris, moisture, and even more mold spores to penetrate and further damage the concrete surface.

Moreover, as the mold colony expands, it releases more and more spores into the air, which can increase the risk of respiratory infections, allergies, skin irritations, and other health issues.

In addition to health risks, mold growth on concrete can also be unsightly, leaving mildew stains and a foul odor in enclosed spaces. It’s important to address mold growth on concrete as soon as possible to prevent further damage and potential health hazards.


Ways to Stop Mold Growth on Concrete

Moisture control is the best way to prevent mold growth on concrete. Although wiping the walls and removing dust and debris can help reduce mold problems, it’s not a daily solution.

Dust and debris settle on walls and initiate mold. Mold requires water to thrive, so reducing water supply to your concrete surfaces will limit mold growth.

Moisture control will also enhance your comfort, prevent mold growth on all surfaces, and reduce health risks. Damp can enter concrete via three main sources: condensation, rising damp, and penetrating damp.

You can prevent condensation by improving ventilation and installing vent fans, an AC system that dries outdoor air, or investing in a ventilation system.

Rising and penetrating damp can be prevented by installing a drainage system and redirecting water away from walls and foundation.

Applying a penetrating primer on the concrete surface is also an effective way to make moisture and rainwater less likely to penetrate the concrete slabs and initiate mold growth.

  • Identify the cause of the mold growth: This could be due to moisture buildup, poor ventilation, or other underlying issues. Once you identify the cause, you can take steps to prevent it.


  • Clean the concrete surface: If you notice mold growth on concrete, it’s essential to clean the surface thoroughly. Use a solution of water and bleach to scrub the affected areas. Be sure to wear gloves and protective eyewear during the cleaning process.


  • Increase ventilation: Good air circulation can help prevent mold growth on concrete. If possible, open windows and doors to increase airflow.


  • Reduce moisture buildup: Moisture is a significant contributor to mold growth. Make sure there are no leaks in the walls or ceiling that could be causing moisture buildup. You can also use a dehumidifier to reduce humidity levels.


  • Use mold-resistant paint: If you’re planning to paint the concrete surface, consider using mold-resistant paint. This type of paint contains antimicrobial properties that can prevent mold growth.


  • Maintain a clean environment: Regularly clean and disinfect the concrete surface to prevent mold growth. Remove any clutter or debris that could trap moisture and create a favorable environment for mold.


  • Hire a professional: If the mold growth on concrete is extensive, it’s best to hire a professional mold remediation company to handle the issue. They have the experience and equipment needed to properly clean and remove mold from the concrete surface.


Summaries On Concrete Mold Growth

Concrete may not be organic, but it can still provide a suitable environment for mold growth by accumulating tiny particles such as dust, debris, hair, and dead skin cells.

Mold spores can also be transmitted to concrete surfaces from nearby organic materials like drywall, rocksheet, carpets, or wood, which can trigger fungal growth.

To prevent mold growth on concrete, it’s important to focus on reducing moisture levels, preventing basement flooding, and maintaining dry indoor air. Spending hours trying to clean the concrete may not be practical or effective.

If you need professional assistance in dealing with mold growth on your concrete surfaces, please call the number provided on this page for expert support. We hope this information has been useful to you.



mold growing on a concrete wall

25 Years of Experience

We Tackle Water Damage & Mold Remediation In Your Area.


Water Damage Restoration

Mold Remediation

Wow, this really worked, thanks!

J. Sullivan – New Orleans