Causes Of Mold In The Basement
Understanding how and why mold found its way into your basement is vital. You dont want to waste time getting rid of it only for it to reoccur.
Lets briefly delve into the science behind mold. Your unwanted home invader is the result of fungi species that generate spores to reproduce.
When these teeny-tiny spores, invisible to the naked eye, land on something wet, they start to grow. Theres no way for mold to thrive and survive without moisture .
Now that youre versed in mold 101, you can likely anticipate what the causes would be. These are the reasons why your basement could have been affected:
- After flooding: A flooded basement is an optimal environment for mold. Standing water and damp items such as furniture and carpets can serve as breeding grounds.
- Water leaks: As with post-flood moisture, leaky pipes, appliances or drains in your basement will increase your risk of finding a moldy surprise.
- High humidity: If the old stereotype of your basement as a damp and dank place applies, your chances of mold will be higher. Humidifiers, air vents and similar steamy gadgets or mechanisms can all encourage mold.
How To Remove Mold From Concrete Basement Walls
- Written by Cameron Sherber on Apr 09, 2010To ensure our content is always up-to-date with current information, best practices, and professional advice, articles are routinely reviewed by industry experts with years of hands-on experience.Reviewed by
If your concrete basement walls have recently fallen victim to mold infestation, you may be wondering how to go about getting rid of it. Below are the necessary steps to remove such an infestation from your home.
Step 1 – Clean Your Basement Walls
Before you can begin the mold removal process, you must give your concrete basement walls a thorough cleaning. Begin this step by combining warm water with a mild brand of soap. Next, pour the newly formed cleaning solution into an empty spray bottle and proceed to vigorously apply it to your mold-laden basement walls. You’ll now need to use a sponge or scrub brush to wipe the walls clean, taking care to fully purge any caked-on dirt deposits. Any remaining dirt or debris stands to cause problems when the mold removal process is underway, so when performing this step, take your time. Once your walls have been sufficiently cleaned, you’ll be ready to move on.
Step 2 – Apply Your Bleach
Step 3 – Apply Your Finishing Touches
Preventing A Reoccurrence Of Mold
As important as it is to clean mold on basement walls, it is equally important to take steps to keep the mold from returning. As mentioned, most mold problems in basements are due to a lack of ventilation and the presence of high humidity. You can alleviate the humidity in your basement by using a dehumidifier. These units can be found for under $300. I recommend a model that will self-empty, having pump-out capability or by continuously draining through a garden hose that can be directed down a drain. Here is more on selecting the right dehumidifier.
Another preventative step you can take is to primer/paint the concrete walls with a mold resistant product after the removal process. An excellent choice is . These mold resistant products will range in price from $30-$50 per gallon. Most of these mold resistant primers and paints contain antimicrobial ingredients that help prevent mold re-growth in areas of high moisture content. Warning I never recommend attempting to cover, seal, or paint over mold in any situation.
The goal is not to kill the mold but to completely remove it.
Consider the following example: If you have a skunk living under your front porch, you have a problem. If you kill the skunk you havent solved your problem, you have just created a different problem. Now you have a dead skunk under your porch. The same goes for mold. Dont be happy with just killing it it needs to be removed.
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How To Kill Mold In Basements
- Spray mold-killing chemicals on surfaces affected by mold. Wear gloves, mask, and proper clothing when handling chemical products.
- Remove items that are heavily infested by mold. Discard them immediately. For objects that can still be recovered, make sure you clean them thoroughly.
- Dry the surfaces. Ensure proper ventilation after cleaning the mold to ensure it doesnt grow back. Use air movers, fans, or simply open doors and windows to facilitate faster drying of your basement.
Keep The Surfaces Dry

To start with, wear disposable gloves. Use a scrubbing pad, paper towel or old toothbrush to scrub the surfaces. In case of painted walls, you must only use paper towels or tissue paper. Remove the blackened mold and lightly scrub where needed. You may also dampen the toothbrush if needed to get the job done easily. Now, use a dry rag or paper towel and pat the surfaces dry. You must ensure that the surface is completely dry at the end of cleaning. Discard all cleaning rags and gloves after use. This is very important to prevent mildew on walls from coming back.
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Know Your Mold And Mildew
Mold can grow in your home wherever theres an abundance of moisture, especially when its allowed to remain for extended periods of time. Mold usually appears on walls, ceilings and floors of homes where moisture management is not at its best. In particular, basements, shower walls and windowsills are areas where mold commonly likes to live. Mold and mildew, for all intents and purposes, are essentially the same thing mildew is generically used to describe many minor mold problems in the home, such as on shower tile grout. However, some molds can become highly toxic to people if left to prosper. Mold can cause allergic reactions, asthma and other respiratory complications, and is especially a risk for small children, the elderly and those with existing respiratory illnesses or weakened immune systems. Mold can appear in many shapes and colors, none of which accurately determines the actual species of mold. However, it does commonly present itself in various tints of black, white, green or blue, and in many combinations of these and other colors.
My Basement Leaked During Heavy Rain And A Towel Was Left On The Floor Upon Removing The Towel The Floor Was Slimy And Black How Do I Clean It Up
Assuming the floor is concrete, spray the area with a Borax/water solution. Clean up the solution and any debris with paper towels.
Occasionally the mold growth will leave behind a stain, even after a vigorous cleaning. The staining is an aesthetic rather than a health issue. If this occurs, steam/pressure cleaning may be necessary.
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Homemade Mold Remover Spray Recipes
Use the spray suggested for the type of surface youre cleaning. Do not use these sprays at the same time or immediately after each other since their ingredients should not be combined. Do not store unused portions theyll lose effectiveness after 2-3 hours. Keep the sprays away from children and pets, and use proper ventilation at all times.
Scrub The Mold With A Mixture Of Water And Bleach
Now you will want to know, what kills mold? Will bleach help in killing mold? Bleach is the ultimate solution to remove mold. But only bleach might not be enough.
Take an amount of bleach and mix it with water. Then take a scrub brush and scrub the moldy area.
Make sure youre wearing safety glasses to prevent any splashes from the scrubbing.
Dip the scrub brush in the mold and clean the concrete wall. After the mold is gone, you must rinse the area with clean water.
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What Is Black Mold
Black mold is often found inside houses with excessive moisture damage to wallboard and other surfaces. Much is made of this type of molds toxicity but the mold itself isnt harmful. It does however have the potential to produce mycotoxins that can cause harm to people and pets, depending on the particular species of mold. A rule of thumb should be use caution when removing all molds, especially when in abundance.
Quickly Stop The Source Of Moisture To Prevent Mold From Growing Further
Depending on the problem, you may have to perform significant repairs to stop the moisture. If its a leaky pipe, condensation in your HVAC system, or a crack in a doorway or window, make sure to either repair or have a professional repair it ASAP. If there is a moisture problem from your basement walls, run a dehumidifier to dry excess humidity.
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Spalling Or Crumbling Walls
Spalling occurs when the concrete in your basement wall begins to crumble, while also causing flaking and chipping. However, spalling is a more serious problem that you must address immediately. If you fail to do that, you may have to replace the entire concrete wall.
Just like some other stains, spalling results when water penetrates your wall. If the water carries salt, it may fill the spaces between concrete particles.
When the salt expands, they increase these spaces, causing the concrete to break and flake away. Therefore, keeping humidity levels low is one of the sure-fire ways of avoiding this problem.
This video explains how you can minimize humidity in your basement and garage:
Basement Mold Removal With Borax

Borax: While perhaps not quite as non-toxic as some of the other aforementioned solutions, borax is still a better alternative than stronger chemical solutions and also deodorizes.
Each cup of Borax should be combined with one gallon of water and applied to mold. Its best to scrub the surface with a sponge or something stiff such as a scrub brush.
Borax does not require rinsing and can be left on surfaces safely.
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How To Remove Mold From Brick Walls
Timely removal of mold from brick walls to eliminate the risk of all types of dangers that come with its existence. Thankfully, the majority of mold situations can be settled at home by DIY methods using different types of solutions. If you suspect mold on brick walls in your house then here is what you need to do in order to get rid of it.
Here are a few things that you need to keep in mind.
- Use a ladder for areas that are beyond your reach.
- Discard the sponge, brush, and plastic sheet once you are done. We are saying this because the toxins might have settled on these items.
- No mold removal should be carried out by sick and weak individuals.
- Children and pets should be away while you are removing mold.
How To Remove Mold From Concrete Patio
Removing mold from an outdoor surface offers a broader range of options than mold removal for an indoor space. The best means for cleaning a concrete patio is a pressure washer with a PSI range of 100 to 200 PSI with a concentrated cleaner designed for mold removal.
A pressure washer will allow you to cover a large amount of space in a short amount of time.
Begin by adding the concentrate to the pressure washers tank and use a light pressure nozzle that wont damage the concrete. Apply the cleaner to the patio in a sweeping motion, working from the house outward to avoid directing high-pressure water at the homes foundation.
After applying the cleaner:
If you dont have a power washer, use a hose with a sprayer. Youll need to apply a solution of vinegar or bleach and water and scrub with a brush before rinsing as the hose will not produce enough pressure to remove all of the molds on its own.
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What Is White Mold
White mold is often found in cool, damp environments such as in basements on walls and other structures. It is often confused with efflorescence, which is a mineral deposit that forms on foundation walls and other masonry surfaces due to water seepage. You can test to see if its mold by spraying it with water. If it dissolves, it is a mineral deposit if it does not, then its most likely white mold.
Spray Basement Walls With Cleaning Solution
Pour your solution of choice into a spray bottle. To remove mold from basement, heavily spritz the surface with the solution. Be sure to let the solution soak in for a while before scrubbing to help get rid of mold youll want to ensure all spores are killed off before taking a bristle brush to the concrete wall. After waiting for about 30 minutes, scrub vigorously with the scrub brush.
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Basement Mold Removal Conclusion
Mold can be a very dangerous substance if it is not treated properly. It can cause respiratory problems, skin irritation, etc. That is why it is important to take care of any mold problems as soon as they are noticed. If the problem is not taken care of, it will only get worse and could potentially cause extensive damage to your home.
Mold can grow on almost any surface, so it is important to be aware of the signs of a mold problem. If you do see any of these signs, take action right away and call a professional to remove the mold. Prevention is always the best solution, so be sure to keep your home clean and dry and make sure that all of your air vents are working properly.
How To Remove Mold From Painted Wall
Anyone that has a moisture of humidity problem in their home will end up having mold on the walls.
That is unless you took the right steps to fix the moisture problem.
If you have mold growing on your walls, like most people, you probably cleaned it with bleach or some other mold removal product.
However, to your surprise, it came back days later.
If the growth returned, you probably didnt fix the moisture problem correctly the first time around.
Mold growing on painted walls can be resilient.
If you fail to get rid of the moisture source, it will keep coming back no matter how many times you try to clean it or paint over it.
The regrowth happens because chemicals applied often will not penetrate deep below the surface where the roots continue to grow.
When the roots keep getting a constant moisture source, the mold continues to develop.
Applying mold removers is only a temporary measure and only stops mold development when the killing agent stays active.
Once the killing agent evaporates, the regrowth will just happen again and again. That is until you find and stop the moisture source.
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How To Identify Mold In Your Basement
The first step to victory is knowing your enemy. Certain colonies of mold can be more hazardous to your health than others, and might best be left to the professionals.
As there are tens of thousands of fungi species that beget mold spores, weve narrowed it down to the most likely culprits . Compare your mold to these 12 common genera of fungi:
Remove Mold In Basement With Tea Tree Oil

Tea-Tree Oil: Conveniently, tea-tree oil is a natural fungicide and is a fantastic solution for removing mold. One of the easiest ways to use tea-tree oil for mold removal is to mix the oil with water.
Shake well to help the oil and water mix together. The next step is to spray where the mold is growing and scrub the surface until the mold starts to disappear.
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Clean Your Concrete Wall Using Ammonia
Did you know that you can make a cement cleaner using ammonia?
Ammonia is one of the best concrete cleaners since it quickly breaks down grease and grime. Therefore, you can rely on it to remove stubborn stains.
Heres what you need to create an ammonia-based concrete cleaner:
- Dish detergent
- ¼ cup ammonia
- A bucket
- A stiff nylon brush
To make the solution, mix ¼ cup ammonia, a few squirts of detergent, and water in the bucket. Using the nylon brush, scrub the solution from one end of your wall to the other until youve covered the entire surface. After that, hose off the wall and dry it with a clean towel.
Tip: Ensure your basement is well-ventilated when using the ammonia solution by fully opening all windows and doors.