First, you'll need to make sure that there's no run-off of the bleach onto any surrounding plant life. Plants that come into contact with bleach will die. Second, bleach isn't suitable for man-made concrete slabs – only natural paving stones. Bleach will fade artificial slabs over time.
K-Seal Max-Strength Patio Cleaner is a professional patio cleaner. It is designed to remove ingrained dirt and stubborn stains from a wide variety of paving surfaces including: Block paving. Concrete slabs.
Overall, we recommend Zep Purple Pressure Wash (US$13.98, The Home Depot). Alkaline cleaners are great for lifting oil stains, grease stains, and other petroleum-based stains from concrete. It's an added benefit that you can use it with a pressure washer, making the job that much easier.
In fact, vinegar removes mold from concrete better than bleach. Bleach will only remove the top layer of mold, causing the mold to return.
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.
Use a specialist cleaner
Try a specialist cleaner like Wet & Forget, at Walmart, which you spray onto the surface of the paving and leave. It can also be used on steps, fountains, patio umbrellas and other smaller outdoor areas. It's bleach-free and non-acidic but will remove mold, moss and grime without any scrubbing.
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 patio slabs with bleach
It is important for us to mention that it may be more environmentally friendly to use detergents than bleach. The bleach will get into the cracks and dramatically improve the look of your patio by killing things like weeds, moss, and algae.
Let the solution sit: Allow the bleach solution to sit on the patio for 10-15 minutes. This will give it time to break down any dirt and grime. Rinse the patio: Use the garden hose or pressure washer to rinse off the bleach solution, starting at the opposite end from where you applied it.
Make this simple homemade patio cleaner to get your concrete or pavers looking brand new. Make a paste with two parts of baking soda to one part of vinegar. Spread the paste on the patio surface and scrub with a brush (we like a long-handled one so you don't have to bend over).
Use Bleach
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.
You can use a pressure washer on wooden decking, stones or brick paved patios which are bound together with concrete. However, we don't recommend using it to clean a block-paved patio, as it will simply wash away all the sand and dirt which binds the bricks together.
Scrub the concrete with a nylon-bristled brush and then rinse thoroughly with the garden hose. For extremely heavy stains, a power washer provides a much stronger stream of water to blast away the grime. Use a hose to rinse greenery after the patio is clean.
Use a detergent such as Dawn or Ajax dishwashing liquid mixed with water to brighten a concrete patio that hasn't been cleaned in a while. Just as you would regularly vacuum the floor and dust your furniture inside your house, you should keep your patio clean so it's ready at a moment's notice to entertain.
While researching how to remove patio black spots you may have come across “Sodium Hypochlorite” which is a very strong bleach and while it may remove black spots, it will also damage the surface of anything it comes into contact with.
Tailored to tough cleaning jobs, you'll want to opt for the white vinegar patio cleaning method if you are freshening up a very dirty patio or removing dirt from high traffic outdoor areas. However, please note that you shouldn't use this method on limestone pavers as the acid will permanently damage their surface.
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.
Mix equal parts water and vinegar and apply it to concrete. If this stain removal technique doesn't work, use 100% vinegar and scrub stains out. This solution can work on many surfaces, including car seats and hardwood floors.
You can power wash concrete all year as long as the temperature is about 40 degrees Fahrenheit. Most homeowners and businesses prefer to do it in the spring or summer to reduce the spread and growth of algae and mold. It also reduces pollen, which can affect allergies.