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Mold Damage Cleanup and Remediation

Can Mold Grow on Concrete? 5 Ways To Prevent It

A newly constructed basement with concrete floors, walls open to the studs, and windows letting in natural light.

Yes, mold can grow on concrete. Cement and concrete surfaces are porous and can become fertile ground for mold spores to grow. Prevention is possible, though, with these five steps.

Concrete and cement surfaces are not mold-proof. If conditions are right, mold on concrete walls can grow quickly.

Surfaces such as concrete seem impermeable, but they can be quite porous. Concrete wall mold can take hold and multiply if the conditions are right. Without professional remediation, mold can become a major problem for households or businesses.

In this article we’ll cover how to identify mold on concrete, whether it's dangerous, why it grows, and how to prevent future mold growth.

What Does Mold on Concrete Look Like?

Mold on concrete sometimes looks like algae or moss. The appearance will depend on the type of mold and how long it has been there.

Here are a few types of mold that could grow on cement:

  • Black Mold: It appears as patchy dark spots and carries harmful toxins. It's found on damp walls and in basements.
  • Brown Mold: These earthy spots pose mild health risks and grow in basements and garages.
  • Green Mold: It grows on outdoor concrete, especially in shady areas. It looks like moss and carries mild to moderate health risks.
  • White Mold: It's often mistaken for efflorescence on concrete floors and walls. It looks fluffy, soft, or crystal-like.

Over time, mold will break down the material it’s growing on. Assuming ideal mold-growing conditions are maintained and the mold remains unmitigated, surfaces such as concrete can quickly become compromised.

Efflorescence vs. Mold

Sometimes, what appears to be mold is something else. Efflorescence is often mistaken for mold, and with a side-by-side comparison, it’s easy to see why.

Efflorescence is a white deposit left behind on surface materials when water evaporates and is often mistaken for a white mold. Efflorescence can be dissolved or wiped away while staining from mold would need to be scraped or scrubbed off the concrete.

A side-by-side comparison of efflorescence vs mold on concrete.

How To Get Rid of Mold on Concrete

Do you suspect mold in cement or concrete at your property? Contact a professional remediation service provider. Mold is difficult to remove and detrimental to your health. Without professional water damage restoration, you run the risk of repeat mold growth.

After you’ve discovered mold on a concrete surface, we recommend taking these steps immediately:

1. Seal Off the Space

Restrict people from entering the area affected. Mold can cause health issues, especially if you have allergies, asthma, chronic obstructive pulmonary disease (COPD), or are immunocompromised. Exposure to mold spores can cause congestion, eye irritation, coughing, and other symptoms.

Those with existing health issues shouldn’t stay in a moldy space until it's cleaned. Seal off the mold with plastic tarps and tape.

2. Contact a Mold Removal Professional

If mold growing is on concrete at your property, call a professional. Mold removal professionals will:

  • Inspect the area and confirm mold presence.
  • Contain the space and begin mold removal.
  • Ensure the space is dry and address the cause (often plumbing, drainage, or high humidity).
  • Apply a penetrating concrete sealant to prevent recurrence.

Clickable graphic directing to Rainbow Restoration's blog How Does Mold Spread? 5 Common Causes [+ Prevention Tips].

Why Does Mold Grow on Concrete?

Mold has a critical role in nature — breaking down animal carcasses, dead plants, and rotting trees. However,mold growing on concrete in a home or business doesn't serve the same purpose as in nature. Mold can grow on concrete because the material is porous and it needs certain factors to flourish, such as:

  • Oxygen: Mold is a simple, living organism and needs oxygen to live.
  • Temperature: Warm conditions are ideal for mold growth.
  • Humidity: Damp places in your home can promote mold growth.
  • Organic materials: Dirt, dust, insulation, glues, paper, and more serve as food sources for mold.

You’ll want to act fast to prevent mold from spreading.

How To Prevent Mold on Concrete

A mold prevention checklist with five steps, along with two Rainbow Restoration technicians carrying air movers to dry out water damage.

  1. Prevent water seepage: Have your foundation inspected. If water permeates through the basement or walls, consider professional sealants and fillings.
  2. Direct roof runoff away from your home or business: Make sure your gutters are clear. They should direct water away from your property's foundation.
  3. Redirect water away from your foundation: Flooding and rainfall can cause pressure. Consider landscaping that directs water away from your home or business. If problems persist, French drains might help.
  4. Keep surfaces clean: Clean surfaces are less likely to host mold spores. Keep the concrete surfaces clean by sweeping, vacuuming, and using a dry mop to remove dirt and debris.
  5. Check the basement, crawl space, and garage: Mold is likely to grow on various concrete surfaces. Mold needs moisture to grow. Be vigilant. Engage in professional water damage restoration at the first sign of damage.

FAQ About Mold on Concrete

Mold is a common concern for homeowners and businesses. Here are some helpful things to know about mold and how it affects your space.

Is Mold on Concrete Dangerous?

Yes, mold can be hazardous to your health. Black mold is especially problematic, but all carry risks. Spores can affect those with allergies or health issues.

How Long Does It Take for Mold To Grow on Concrete?

Mold can grow as quickly as 24 to 48 hours under ideal conditions. Spores colonize in 3 to 12 days and are visible in 18 to 21 days. Surface types and other conditions can affect growth time.

The longer conditions persist — warmth, dampness, and a food source — the greater the chance mold will grow.

Can Mold Stick to Concrete?

Yes, mold can stick to concrete as long as it has food and moisture. Mold won't feed on concrete, but the dust that settles on it contains enough nutrients for growth. In dusty, moist conditions, mold has all it needs for survival.

What’s the Difference Between Mold and Mildew?

Mold is a fungus that grows in damp areas with a food source and oxygen. Mildew is an early-stage mold common on flat, moist surfaces, such as shower walls.

Mold is usually blue, black, green, or red and looks fuzzy or slimy. Mildew is gray or white and looks dry or powdery. Mildew smells milder than mold, like wet socks. Mold is more acrid and powerful; it's often strong enough to induce nausea.

How Do You Test for Mold on Concrete?

Have a professional test for mold rather than trying it yourself. Touching or breathing mold can be hazardous. A restoration specialist can test for mold and determine how to treat it.

Always Choose Professional Mold Remediation

Although hard surfaces seem impenetrable, when conditions are right, even poured concrete, concrete blocks, and cement can host mold. If you suspect mold growth at your property — on any surface — don’t try to deal with it yourself. Contact a local mold remediation expert for help.

For mold removal, remediation, and prevention services you can rely on, choose Rainbow Restoration®.

Request an appointment online or call (855) 724-6269 to learn more.

This article is intended for general informational purposes only and may not be applicable to every situation. You are responsible for determining the proper course of action for your property. Services should be performed by licensed and experienced professionals. Rainbow Restoration is not responsible for any damages that occur as a result of this blog content or your actions. For the most accurate guidance, contact a Rainbow Restoration professional for a custom, on-site assessment.

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