If you have greenish-black stuff on your concrete patio, it's probably mold, mildew, or moss. Damp or moist conditions from rain or humidity can encourage mold and mildew to grow in those nooks and cracks of concrete pavers or bricks.
Use a Pressure Washer
If you have a small amount of mold or algae, you may find that the first two steps of drying out and sweeping the area is enough to remove it. If this is not the case, pressure washing is often quite effective in removing mold and algae from pavers, bricks or concrete.
The Mold on Paver Problem and Solution
The mold on pavers problem occurs when algae and/or mold and other fungal types grow on damp or moisture-laden pavers. The answer is to eliminate the presence of moisture from underneath. Without moisture, the algae/mold cannot survive.
Vinegar Solution
Spraying a vinegar solution (1 cup of vinegar per gallon of water) onto the surface, saturating it fully, should kill most strains of mold. Vinegar spray can be followed by power washing or manual hand scrubbing to remove the dead mold.
Lichen are white, brown, yellow and black (i.e. "black spot") biological growths that live on slate and concrete tiled roofs, as well as on concrete paths, monoblock drives, brickwork, and occasionally on wall render. Lichen can be very tough to remove and pressure washing alone is ineffective.
Black mold, a type of mold that can potentially pose health risks to humans. It produces mycotoxins, which are toxic substances that can be released into the air when the mold is disturbed or when it grows on damp or decaying materials.
Treat the Area. For a natural solution for getting rid of black mold, combine one part baking soda with five parts distilled white vinegar and five parts water in a spray bottle. Alternatively, you can use a chemical-based mold and mildew remover, all-purpose cleaners, bleach or dish soap.
Scrub with Bleach and Water
Prepare a 50/50 solution of bleach and clean water to use with a soft nylon brush or pad. Allow the bleach and water solution to sit for about 15 minutes after the first scrubbing session, then finish the job by rinsing with clean water and using natural stone cleaner and sealant.
Avoid Leaving Moisture
Mold requires water and moisture to fester and grow. So if you manage to rid the area of water, the mold won't be able to grow. Patio maintenance involves keeping the area dry and clean thoroughly.
Whilst vinegar will not directly dissolve concrete itself, but it will degrade the cement that binds your concrete slabs or flags together. Extended exposure to vinegar will also cause any polish or sealant on your pavers to erode over time, leading to bleaching, stains and weathering.
If your pavers have been sealed, which is a service that we offer, it's a lot easier to maintain and it does slow down mold growth for the simple fact that when your pavers are unsealed, that moisture will sit in the joints and make mold grow. Mold likes damp, dark areas.
Cleaning your pavers with bleach has a lot of benefits: Disinfecting the Surface: Bleach is an effective disinfectant and can kill any bacteria or mold on the surface. This will help to prevent any health hazards from occurring. Removing Tough Stains: Bleach is also effective in removing tough stains from the surface.
White vinegar is a mildly acidic product that cleans, deodorizes, and disinfects. It can also kill 82% of mold species, including black mold, on porous and non-porous surfaces. You can use it safely on most surfaces, and its offensive odor goes away quickly. Pour undiluted white vinegar into a spray bottle.
While it is possible to use bleach to kill mold as well, experts agree that vinegar is a much better option. Unlike bleach, vinegar can effectively kill the mold at the root, which means it's less likely to return. Vinegar is also less toxic than bleach, making it a better choice for household use.
Can you power wash pavers? Power washing (also known as pressure washing) is also a very effective method by which you can remove dust deposits and various stains from your pavers. Just make sure that the water jet is not directed directly at the joints between the paving stones.
This will tell you if you can clean the mold yourself, or if it's reached a point where you need to bring in the pros. If the outbreak is less than 10 square feet, the EPA says it's safe to handle the cleanup yourself (FEMA sets the limit at 25 square feet, so there's some wiggle room).
Use undiluted white vinegar on hard surfaces in kitchens and baths. A bleach solution also works to kill mold. Mix one cup of bleach in a gallon of water, apply to the surface and don't rinse. Mix a 50/50 solution of ammonia and water.
Use soap, water and a scrub brush or sponge to scrub the mold from surfaces. Get rid of any items that have the mold, such as old towels or toiletries.
Black mold is a fungus that grows in warm, damp areas. Its spores may mistakenly trigger an allergic reaction in your immune system. An allergic reaction to black mold may cause various symptoms, including coughing, sneezing, congestion and irritated eyes. However, it rarely makes people very sick.
The most effective chemicals for removing mold stains contain bleach. Even though bleach does not kill mold as well as some other chemicals, it still kills the mold. These chemicals work very quickly: just spray them on, wait a few minutes, scrub with a scrub sponge, and watch the stains begin to lighten up.
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.
Now it's time to shock your pool — preferably with a calcium hypochlorite shock. Shocking increases your pool's chlorine and other chemical levels and is a black algae killer. Now, because black algae are so difficult to kill, we recommend using four times the recommended dosage for your size pool.
Black spots appear when mould and algae have settled into the pores of the paving stones, but before you reach for one of the best patio cleaners on the market and get stuck into how to clean a patio, it's worth considering how to avoid the issue occurring in the first place, and it can help to have a good drainage ...