How to Clean Mold Off Concrete
Choose a cleaning agent to treat the mold., Remove affected items., Apply the solution., Let the solution soak., Rinse outdoor concrete., Dry interior concrete with a towel., Clean items you’ve set aside before placing them back in the area., Check...
Step-by-Step Guide
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Step 1: Choose a cleaning agent to treat the mold.
You can use a mold-killing detergent, diluted bleach, or a commercial cleaner made specifically for killing mold.Don’t mix anything other than water with bleach, as certain cleaning agents can produce highly toxic fumes when mixed with bleach.For a diluted bleach solution, mix three parts water with one part bleach in a bucket.Don’t forget to test a small, discreet area first.
Bleach and other chemicals can discolor concrete that’s been colored or stained. -
Step 2: Remove affected items.
Any organic material adjacent to the moldy area can be infected.
Throw away any disposables like cardboard boxes.
Set aside other removable items like furniture or area rugs. , Use a heavy duty sponge or scrub brush to apply your chosen cleaning solution to all visible moldy areas on the concrete.
Scrub the areas vigorously.
If you’re using mold-killing detergent, apply it directly to the spots and scrub it with a bristle brush.Don’t use a wire brush, which can scratch concrete.Wear old clothes, rubber gloves, safety goggles and a respirator or dust mask. , If the spots aren’t lifting, leave the solution to sit for several minutes.
Then scrub the areas with the solution until the mold is gone., Use a hot water pressure washer for the fastest and most effective rinse.
Wear safety goggles, sturdy footwear and long pants.
Use a pressure rating of at least 3000 psi with a flow rate of at least four gpm (gallons per minute).This should lift any organic matter that has seeped into the pores of the concrete.If you don’t want to use a pressure washer, try a regular water hose.You can rent a pressure washer at a home or building supply store.
You may need a van, pickup truck or SUV to transport it, and a friend to help load and unload it.Ask the rental agent how to use the washer and to give you any safety precautions.
Find out if the washer comes with nozzles.
Don’t use settings finer than fifteen degrees.
Never use a zero degree nozzle on a pressure washer. , Once it’s dry, inspect carefully for any mold that may not have been cleaned.
If there is still visible mold, rinse the area clean and try one of the stronger methods you haven’t used yet: diluted bleach or commercial cleaner., Leather, wood or inorganic furniture can be deep cleaned.
Upholstered furniture with visible mold will need to be disposed of or reupholstered by a professional.
Carpet that shows significant mold growth or is soaked completely through will need to be removed. , Dirt should be slightly sloped away from the house so that water will travel away from the perimeter rather than pool up against the outer walls.
Don’t allow wet leaves or other debris to pile up against the exterior walls of your home.Pooling water can seep into the home and cause mold to grow inside the house.
If your driveway is showing signs of mold, consider removing trees or shrubbery that are blocking sunlight on your driveway.
Mold thrives in damp and shady areas., Sump pumps should discharge water at least twenty feet from your home.
Your gutters should expel water at least six feet away from the exterior walls.
If your gutters are releasing water too close to the home, install gutter extenders., Make sure none of your outside hose spots are dripping.
Examine the perimeter of the building for any potential water dripping or seepage. , If there are any leaks – for example in your piping or roof – repair them.
Insulate your roof, exterior walls, windows and pipes to cut down on moisture that forms condensation., If your mold problem is indoors, increase the ventilation to prevent warm and stagnant air where mold can thrive.
Make sure large appliances are vented, such as your washer and dryer.
Make sure kitchens and bathrooms are well ventilated.
Run air conditioners and dehumidifiers as needed., Seal the concrete with water-proofing chemicals.
Seal any cracks in the concrete walkway around your home with concrete, caulking or tar.If you plan to paint concrete walls, use a waterproof sealant first, then apply stain-blocking primer and paint.For outdoors, try a high quality acrylic sealer made for exterior use.
If your weather tends to be warm and humid, look for a low-solids solvent-based sealer.
Choose dry, sunny weather and allow the sealer to dry for at least two to three days. -
Step 3: Apply the solution.
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Step 4: Let the solution soak.
-
Step 5: Rinse outdoor concrete.
-
Step 6: Dry interior concrete with a towel.
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Step 7: Clean items you’ve set aside before placing them back in the area.
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Step 8: Check the land for sloping and debris.
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Step 9: Examine how water is discharged outside.
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Step 10: Check for water seepage.
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Step 11: Stop interior leaks and condensation.
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Step 12: Reduce the humidity indoors.
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Step 13: Waterproof the concrete.
Detailed Guide
You can use a mold-killing detergent, diluted bleach, or a commercial cleaner made specifically for killing mold.Don’t mix anything other than water with bleach, as certain cleaning agents can produce highly toxic fumes when mixed with bleach.For a diluted bleach solution, mix three parts water with one part bleach in a bucket.Don’t forget to test a small, discreet area first.
Bleach and other chemicals can discolor concrete that’s been colored or stained.
Any organic material adjacent to the moldy area can be infected.
Throw away any disposables like cardboard boxes.
Set aside other removable items like furniture or area rugs. , Use a heavy duty sponge or scrub brush to apply your chosen cleaning solution to all visible moldy areas on the concrete.
Scrub the areas vigorously.
If you’re using mold-killing detergent, apply it directly to the spots and scrub it with a bristle brush.Don’t use a wire brush, which can scratch concrete.Wear old clothes, rubber gloves, safety goggles and a respirator or dust mask. , If the spots aren’t lifting, leave the solution to sit for several minutes.
Then scrub the areas with the solution until the mold is gone., Use a hot water pressure washer for the fastest and most effective rinse.
Wear safety goggles, sturdy footwear and long pants.
Use a pressure rating of at least 3000 psi with a flow rate of at least four gpm (gallons per minute).This should lift any organic matter that has seeped into the pores of the concrete.If you don’t want to use a pressure washer, try a regular water hose.You can rent a pressure washer at a home or building supply store.
You may need a van, pickup truck or SUV to transport it, and a friend to help load and unload it.Ask the rental agent how to use the washer and to give you any safety precautions.
Find out if the washer comes with nozzles.
Don’t use settings finer than fifteen degrees.
Never use a zero degree nozzle on a pressure washer. , Once it’s dry, inspect carefully for any mold that may not have been cleaned.
If there is still visible mold, rinse the area clean and try one of the stronger methods you haven’t used yet: diluted bleach or commercial cleaner., Leather, wood or inorganic furniture can be deep cleaned.
Upholstered furniture with visible mold will need to be disposed of or reupholstered by a professional.
Carpet that shows significant mold growth or is soaked completely through will need to be removed. , Dirt should be slightly sloped away from the house so that water will travel away from the perimeter rather than pool up against the outer walls.
Don’t allow wet leaves or other debris to pile up against the exterior walls of your home.Pooling water can seep into the home and cause mold to grow inside the house.
If your driveway is showing signs of mold, consider removing trees or shrubbery that are blocking sunlight on your driveway.
Mold thrives in damp and shady areas., Sump pumps should discharge water at least twenty feet from your home.
Your gutters should expel water at least six feet away from the exterior walls.
If your gutters are releasing water too close to the home, install gutter extenders., Make sure none of your outside hose spots are dripping.
Examine the perimeter of the building for any potential water dripping or seepage. , If there are any leaks – for example in your piping or roof – repair them.
Insulate your roof, exterior walls, windows and pipes to cut down on moisture that forms condensation., If your mold problem is indoors, increase the ventilation to prevent warm and stagnant air where mold can thrive.
Make sure large appliances are vented, such as your washer and dryer.
Make sure kitchens and bathrooms are well ventilated.
Run air conditioners and dehumidifiers as needed., Seal the concrete with water-proofing chemicals.
Seal any cracks in the concrete walkway around your home with concrete, caulking or tar.If you plan to paint concrete walls, use a waterproof sealant first, then apply stain-blocking primer and paint.For outdoors, try a high quality acrylic sealer made for exterior use.
If your weather tends to be warm and humid, look for a low-solids solvent-based sealer.
Choose dry, sunny weather and allow the sealer to dry for at least two to three days.
About the Author
Deborah Ramos
Brings years of experience writing about lifestyle and related subjects.
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