A dish soap, like Dawn, is a safe place to start. The surfactants in dish soaps are designed to remove oil and grease, they're gentle enough to be used without issue on your pavers. In a bowl or bucket, mix the soap with water and pour it onto the stain and agitate. Rinse and repeat if needed.
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.
Simply put, black stains on flagstones are caused by certain types of mold and mildew. These fungi find their way onto the stones either from their spores landing on the stones or from simply extending onto the stones from patches of mold or mildew right beside them—a pretty common occurrence for garden pavers.
Try Concrete Stain
The simplest path to reviving tired pavers is to apply an acrylic-based semitransparent concrete stain, such as Behr Premium Semi-transparent Concrete Stain ($27/gal.; Home Depot) or Valspar Semi-transparent Concrete Stain ($28/gal.; Lowe's).
One of the best things for household stains is white vinegar, and the same can be said for how it targets stubborn garden dirt. This eco-friendly solution is made up of equal parts vinegar and water, which is then left to soak into the patio to correct any discolouration and also remove tough marks.
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.
This is a common problem. It could either be mildew, or a reaction from tannin in the wood. Given that you have black residue on rocks, it may be mildew.
Vinegar is extremely effective against removing efflorescence from any surface, whether it be interlocking pavers, concrete pavers or bricks.
Water and mild dish soap is a popular cleaning solution because it's easy to find at home and it won't damage brick, but it will tackle stains. The BIA recommends using hot water for surface cleaning with a detergent. White vinegar and water, another common household cleaner, can also be used on mildew.
You can use bleach and water. You'll want to use one part bleach, 10 parts water to create a good cleaning mixture. Or you can do like the professional painters do, and use TSP or trisodium phosphate for a great cleaning solution.
Let the vinegar sit for about 5 minutes then scrub it off using a stiff-bristled brush. Then rinse the vinegar with hot water and spray the area again. This time, you don't need to rinse away the vinegar; leave it to let it penetrate the brick and kill the mold that's on the interior.
To clean paver slabs, you can use a detergent, such as Dawn, or a vinegar-water solution that is gentle enough to effectively clean without causing damage to your concrete pavers.
OxiClean is a powerful concrete cleaner that works well on various materials, including pavement and grout. This concentrated solution provides excellent cleaning without leaving residue.
Apply Black Spot Remover Plus with a pump-up sprayer or watering can (make sure you rinse out the sprayer or watering can afterwards). Flood the surface, the surface of your patio should be visibly wet. Make sure you spread the black spot remover over the surface and then leave it to dwell.
And, while it may be tempting to use household bleach for a quick clean, Beril says that this can ruin the patio stones and leave them looking patchy. 'There are many specialist patio cleaning products on the market including brick acid,' she cautions.
Patio Black Spot Remover is currently the only product developed specifically to safely remove those hideous black spots and restore the natural colour to garden stonework. Patio Black Spot Remover for Natural Stone will remove black lichen from all types of natural stone, including green algae and white fungi.
Although bleach is great at the whitening effect, you can use peroxide to achieve this. Hydrogen peroxide is an oxygenated bleach. It is safe for plants, so when you rinse this solution, it won't harm anything. It works together with the dish soap and baking soda to remove dirt and whiten dirty concrete.
White vinegar is good for cleaning pavers, though it's also acidic enough to erode the stones' surface. Diluted vinegar can be used safely to clean paving stones, though it should be used sparingly and infrequently to protect your paving from damage.
Combine 1 teaspoon of hydrogen peroxide and 1 teaspoon of milk in a glass bowl. Dip cotton pad or Q-tip in the bowl and apply to dark spots. Leave on for 15 minutes. Rinse with lukewarm water and finish off with your favorite serum and moisturizer.
Leave the white vinegar for 1 hour or so to let the vinegar work its way into the paver slabs. Spray the surface with soap and water, then scrub off. Rinse with warm water, then let dry. You may repeat the process if there are stains left.
Mix Solution of dish soap and water, and use a brush to scrub the pavers clean. Make sure to rinse the pavers thoroughly afterward. This process may need to be repeated for tough stains. A recommendation is to do this every few months.