How To Get Rid Of Mold On Concrete Block Walls: 5 Easy Steps

You can easily find an easy solution on the internet on how to get rid of mold on concrete block walls, but it will eventually come back if you do not do it correctly. Fortunately, we’ve got the best method you can do to remove it and prevent mold from growing again.


how to get rid of mold on concrete block walls

Why Does Mold Grow On Concrete?

Two main reasons trigger mold growth: moisture and food. The dust particles and other organic material on the wall can act as a nutrient source for molds and mildew. If your house is often cleaned and there is only a minimal amount of dust in the atmosphere, it lowers the risk of mold growth.

On the other hand, moisture is harder to deal with. There are two ways in how it can foster molds in your concrete block walls.


Water intrusion

Most houses have a draining system where water can pass through without going into the main structure. Unfortunately, it can still penetrate walls in some cases, especially if there are existing cracks and holes through the concrete. If the block wall is not properly sealed and painted, the water can still enter the exposed parts.

It can also come from existing water damage. Check out this article to know more about removing mold from water damage easily.



Concrete is not a good insulator. When warm water meets a colder surface, it can create condensation that can sit on the wall.

You may notice wet spots on the concrete wall where there is an accumulation of water and moisture, most referred to as concrete sweating. It would help if you addressed this matter as soon as possible to prevent the dangers of concrete sweating.


What Type Of Mold Grows On Concrete?

Black mold is the most common one that grows on concrete is the black mold. It loves consistently damp areas. If your concrete wall is often left wet for more extended periods, there’s no surprise when it starts developing molds on the surface.

Mold can be dangerous if left untreated, especially for people with severe allergic conditions and asthma. It can also irritate the nose, eyes, skin, throat, and lungs.

If you are still unsure what type of mold is growing in your home, you can hire a professional to help you. The mold inspection cost varies depending on several factors, and you can find the best one that suits your situation.


What Kills Black Mold On Concrete?

There are available mold-killing detergents in most stores and online, so sourcing it would be an easy task. You can also use a bleach mixture and vinegar to remove mold from concrete walls. If you are using vinegar, be careful because its acidity can melt the sealer.


How To Remove Mold Growth On Concrete Block Walls

Before cleaning, it is essential to prep the surface first. You can do this by finding the cause of the moisture.

If there was a recent flood, dry the area using dehumidifiers, fans, or let the airflow through the room. You could also search for a possible plumbing issue. After this, you can now start with cleaning.


Step #1. Prepare the equipment

For this method, you will need safety gear such as gloves, safety glasses, and a dust mask, preferably rate N95. You will also need a brush, a bottle spray, dish detergent, sanitizer, and a shop vacuum with a HEPA filter.


Step #2. Vacuum the excess mold

Remove the excess mold on the surface to clear out the area you are going to work with.


Step #3. Spray the cleaner

Using the cleaner you have, like Oxiclean and RMR-86, spray the moldy parts generously until it gets soaked. With this process, you will see the molds starting to disappear after 15 seconds. Repeat the spraying if you do not see any changes after a minute.

You can also find a bleach solution to do this. Scrub the moldy area with the mixture aggressively until it is gone. Be sure to wear protective glasses to keep them from splashing your eyes.


Step #4. Rinse

If the wall is indoors, use water and a cloth to remove the cleaner off the concrete.


Step #5. Dry

It would be best to dry the concrete for at least 24 hours before starting to do whatever you want with it. You can also use dehumidifiers and fans for this step. To prevent mold from growing back, use mold preventer sprays or mold repellent paint.



Now that you know how to get rid of mold on concrete block walls, it will be one thing less from keeping your wall’s pristine appearance. If you don’t want them to grow again, it is best to use repellents now rather than deal with them later.

You don’t need to go out of your way to make your home safe from infestations and other related problems. You can always go back to this article as a guide.

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