Combine 1/4 cup of liquid bleach with 1 gallon of hot water in a large bucket. To avoid damaging your lawn or walkways, always dilute your bleach and control your runoff when rinsing. Soak your brush in the solution and scrub the entire area until it's fully saturated.
Vinegar is a natural and safe alternative to cleaning concrete with harsh chemicals. In the case of algae and mold, it does a better job than bleach, and it is better in the long term for killing these infestations. Oftentimes, vinegar can be found in your home or garage.
Mix one part bleach to four parts water. Wipe and gently scrub the mould until it is gone. Finish by wiping away the bleach mixture and dry the area well with a soft cloth.
Vinegar Solution
Vinegar is the perfect option in such cases. Used similarly to bleach, vinegar is known to kill many species of fungus including harmful mold. Spraying a vinegar solution (1 cup of vinegar per gallon of water) onto the surface, saturating it fully, should kill most strains of mold.
For a diluted bleach solution, mix three parts water with one part bleach in a bucket. You can also use white vinegar to kill mold. Don't forget to test a small, discreet area first. Bleach and other chemicals can discolor concrete that's been colored or stained.
But that's not all; chlorine bleach can also be used for cleaning the concrete driveway. Of course, you should dilute it with equal parts of water or a 1:1 ratio. With the mixture ready, spray it on the driveway, allowing it to sit for 10 minutes. Then, use a stiff brush before rinsing with clean water.
As a gentler cleaner, bleach can't harm concrete's durable material. Aside from being an effective cleaner and stain remover, it also acts as a disinfectant to the concrete surface.
In a study testing the effects of various mold-killers, hydrogen peroxide was found to be moderately effective at killing mold on nonporous surfaces, albeit less potently than bleach.
Mold professionals use expensive, professional equipment such as HEPA (High Efficiency Particulate Air) air scrubbers, HEPA vacuums, commercial-strength dehumidifiers, etc. Regular handymen won't have that stuff.
Vinegar is an all-natural solution for cleaning concrete. It kills mildew and mold, removes grime, and helps treat set-in stains. Before cleaning concrete with vinegar, it's essential to dilute it so you don't affect your sealer. Here's what type of concrete to clean with vinegar and which types to avoid.
You can also use a rubbing alcohol solution mixed with some dish detergent if you do not have any bleach available. Mix 2 parts isopropyl alcohol with 1 part dish-washing liquid, then apply the solution using a spray bottle. Wait for five minutes before wiping it off with paper towels.
Try a chemical solution.
Combine one part bleach to three parts water in a bucket. Other options are a borax and water solution, a baking soda and water solution, 3% hydrogen peroxide, or undiluted, distilled white vinegar, any of which can be applied using a quart-sized spray bottle.
Baking soda is another powerful way to clean and eliminate mold. Combine vinegar and baking soda by mixing them into a paste, and apply to affected areas. With a little elbow grease, it's a safe alternative to bleach and is safer to use in households with kids and pets running around.
Spray vinegar onto the moldy surface and leave it for an hour. Then wipe the area clean with water and allow the surface to dry. Any smell should clear within a few hours. While it's safe to use on most surfaces, vinegar is unlikely to be effective at cleaning mold off of soft surfaces.
Pour enough undiluted white vinegar into the empty spray bottle to cover the area of mold growth. Spray the mold directly, fully saturating it with the vinegar, and allow the vinegar to sit for at least an hour. Don't be tempted to scrub or rinse; the mold needs time to completely absorb the vinegar.
To clean mold, use regular white distilled vinegar, typically sold with five percent acidity. You can also use “cleaning vinegar” with its six percent acidity. Both are effective at killing mold.
Using Hydrogen Peroxide to Kill Mold
Hydrogen peroxide kills mold effectively on materials such as clothing, floors, bathroom fixtures, walls and items such as kitchen appliances. Pour 3% concentration hydrogen peroxide into a spray bottle. Spray the moldy surface completely to saturate the area with hydrogen peroxide.
Mildew is a surface fungi identified as a patch of gray or white fungus lying on the surface of a moist area. Mildew is easily treated with a store-bought cleaner and a scrubbing brush. Mold, on the other hand, can have colors that range from black to green and is often the result of a much larger infestation.
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Steps for removing mold
Scrub the affected area with soap and water to clean up most of the mold. Use a detergent or soap, like Dawn dish soap. 2. Next, spray your disinfectant of choice over the affected AND SURROUNDING AREAS.
To clean mold, use regular white distilled vinegar, typically sold with 5% acidity. You can also use “cleaning vinegar” with 6% acidity. Both are effective at killing mold. Generic brands are as effective as name brands.
Now, you can use regular liquid chlorine bleach to clean away mold and mildew, but I'd suggest using oxygen bleach powder instead. Oxygen bleach costs a bit more, but if you spill any on your clothing, carpeting or upholstery, it won't bleach out the color.
Apply the bleach solution
Allow the bleach solution to contact the surface for up to 15 minutes. Work in smaller sections if the patio is too large to finish in that time.
Cleaning concrete with muriatic acid can be a highly effective solution if used correctly, providing ultra-bright white concrete and removal of many types of stains. In one application, you can remove rust stains, oil stains, algae, and paint splatter with a quick chemical application followed by pressure washing.
For lightly soiled concrete, you can remove dirt by using bleach mixed with water. Add 1/8th cup of liquid dishwashing detergent to the solution and pour it into a spray bottle. Spray the solution onto the surface, and let it sit for a few minutes. Scrub with a nylon-bristled brush.