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Removing Black Mold from Concrete

Mold is a dreaded home invader, capable of causing severe health problems and destroying property. With all of the horror stories out there about black mold it’s no surprise it’s one of the worst discoveries for a homeowner.

removing black mold from concreteBecause black mold loves damp or wet areas, like underneath a sink, it’s no surprise it can flourish on concrete that is left wet. There are ways to remove black mold from concrete, although it requires protective gear and some elbow grease. If you want to remove black mould or any other type of mildew from your concrete you’ll need to do the job correctly the first time and prevent it from returning.

Causes of Mold Growth on Concrete

Mold can grow on concrete for a number of reasons. Unfortunately, fungus will make a home anywhere damp or wet, and concrete can become the perfect place when it doesn’t dry properly. If the concrete is in a basement, the black mold may be caused by a leak from outside or faulty plumbing. Homes with high humidity also tend to have problems with mould growing on surfaces as well. Outdoor concrete, such as a patio, usually grows mildew when it doesn’t dry completely after it’s been soaked. This is typical of concrete that’s well shaded.

How to Remove the Mold

The good news is removing black mold on concrete surfaces is fairly easy and straightforward. The main difficulty in removing the mould is the potential health hazards. Mold reproduces through spores released into the air, making it necessary to take precaution when cleaning the surface. Although some household molds will only irritate allergies, black mold can be very dangerous and cause severe health conditions. Removing black mold is just like any other form, it just requires extra care. It’s recommended that you start with the minimum protective gear, such as a mask and heavy-duty gloves. It also requires an N-95 respirator to protect you from spores and goggles. This gear is recommended by the EPA when cleaning mold and will protect you from any spores released into the air.

How to Clean and Disinfect the Affected Areas?

remove black mold from concrete patioCleaning and disinfecting mold-covered concrete is a fairly simple process and there are a few ways to do it. Cleaning outdoor concrete is the simplest because you can use a garden hose to finish the job.

Step 1: To begin you’ll need to create a cleaning solution that’s effective at black mold removal. Use a bucket to mix one-half cup of bleach diluted with one gallon on water. This amount of solution can treat an area about five square feet. If you need to clean a larger area simply double the solution.

Step 2: Simply pour the bleach solution onto the entire affected area and allow it to set for about fifteen minutes. This gives the bleach time to kill the black mould completely.

Step 3: Now make a more concentrated solution with one cup of bleach with one gallon of water. Use a wire scrub brush to scrub the concrete in a circular motion. Although a bit tedious, this will make sure the mildew is completely removed from the surface of the concrete.

Last step: From here you simply use a hose to spray down the affected area, removing the cleaning solution from the surface.

Black Mold on Concrete in Basement

black mold concrete basement removalFor black mold on concrete in a basement, start by ventilating the area well. Because you’ll be using bleach indoors, open a window and escape the fumes when possible. Create a cleaning solution that’s one part bleach to four parts water and apply it to the concrete. Allow this solution to sit for fifteen minutes before using a wire scrub brush to clean the mold off the surface. Make sure you leave the area while the bleach is soaking to prevent breathing in fumes. It’s important to wear protective gear during this process, including rubber gloves and a respirator. After you’ve scrubbed the area, soak up the cleaning solution and apply clean water. Scrub once more and remove all surface water. Allow the area to dry completely. If your basement area is relatively damp, use a fan to dry the floor quickly.

Prevention tips

black mold concretePreventing black mold from entering your home is fairly straightforward, although it requires staying on top of the situation. Because fungus loves to flourish on damp areas, make sure rooms with regular water exposure like the kitchen and bathroom are well-ventilated. Dehumidifiers are helpful is small rooms with high humidity levels. Always check for leaking pipes as well, which are a major cause of household mold. Preventing mold in the basement is a bit trickier. You’ll need to make sure ground water runs away from your home to prevent it from collecting near the basement. Check that sprinklers and downspouts aren’t depositing water near the basement walls or windows. Prevent condensation on basement water pipes by wrapping them. Use an exhaust fan in the bathrooms of your home after showering. Finally, keep the humidity in your basement below 60%. Running a dehumidifier downstairs may be your only option if you live in an area with high humidity.

Tools and Protective Gear

Black mold removal requires a few household tools and some more advanced protective gear. You’ll need a bucket, bleach, disposable rags, rubber gloves, heavy-duty garbage bags to dispose of contaminated material, and a wire scrub brush. It’s also necessary to use good protective gear. For black mold, an N-95 respirator is the minimum advised. You’ll also need goggles to protect your eyes from spores in the air.


Because there are health hazards when you remove black mold from concrete, make sure you always use the proper protective gear. Don’t allow it’s spores to contaminate other areas of your home. Isolating the affected area is important because mildew spreads through spores in the area. When cleaning, use caution with cleaning solutions. Always ventilate the area properly when using bleach as the fumes can overwhelm you. Never mix cleaning solutions because the result can be toxic. Mixing bleach and ammonia is especially dangerous as a poisonous gas is produced. You can also outsource the job to a black mold expert to do it for you.