How to Remove Black Spots from a Patio

As we approach summer, the patio is soon to become a hub of activity. Great as a place for the kids to play, ideal for a gathering with friends, and perhaps the ideal outdoor office when working from home.

Should it have been left neglected over the colder months though, there is the concern that your summer hotspot has now become a summer blackspot.

Black spots can make any surface a lot less welcoming, and once left untreated, they can spread rapidly, turning your patio into something you’d rather avoid than enjoy.

So why has this happened? How are you going to fix it?

What is black spot on a patio?

Black spots on a patio are caused by constant exposure to moisture. This lichen takes root within your patio tiles, rapidly spreading as the surface remains damp and moist.

Should your patio be well-shaded, you’ll notice an even faster spread, and the longer you leave it untreated, the harder it is to remove. This is because the roots of the lichen dig deep and affix themselves to your patio tiles,

Without keeping on top of it, by summer, your patio could require extensive cleaning or even a complete overhaul.

Why am I getting black spots on my patio?

The first thing to think about is, what is your patio made of? Lichen loves a porous surface. It means it can attach itself to the surface easily and has a supply of water and other nutrients it needs.

If you haven’t waterproofed your patio, and it is made of a porous material, you are giving black spot the chance to thrive. Concrete patios, for example, can be a hotbed for black spots, so consider sealing them to help reduce the chances of black spot.

Then look at the positioning of your patio. Does the sun hit it, or is it shaded? If it is covered by trees, you give lichen more of a reason to call your patio home.

If permissible, removing or at least cutting the trees down a little could be all it takes to stop black spots from affecting your patio.

Will black spot damage my patio?

It might, especially if you don’t treat it. The longer the lichen is left untreated, the more it grows and embeds itself within the patio surface. As this happens, it becomes possible for the patio to crack or chip. Sometimes, the damage isn’t noticeable for some time. The surface may appear fine, yet underneath, the roots of the lichen start to destabilise the base layers, leading to a weakened patio surface that, over time, could prove to be dangerous.

Finally, once black spot takes hold, it can make large areas of your patio slippery. Perhaps not much of a concern for adults, but if your patio is used by children, you’ll need to take extra care so that they don’t slip when playing.

How to get rid of black spots on your patio

Firstly, you want to tackle this problem as early as possible. As we mentioned earlier, black spots on your patio can spread rapidly and become harder to remove the longer they are left.

Following the steps below should help you get rid of the black spots and allow you to benefit from a clean and attractive patio this summer.

Prep the area

If your patio is filled with furniture, plant pots, kids' activities and more, remove them all. Then sweep the patio with a stiff brush. You’ll want to ensure all leaves and dirt are removed, along with anything else that could hold moisture. This reduces the number of places the lichen could settle.

Avoid removing this debris with a pressure washer. It might be a quick fix, but long term, it’s causing more damage. The pressure washer will erode parts of your patio surface and give the lichen more of a place to affix its roots.

Choose a method of cleaning the black spots from your patio

There are many ways you can remove black spots from patios. Specialist mould/lichen products are available at garden centres, but they should be used with caution. Some of these products are only suitable for certain surfaces. If you apply a product and it is not suitable, you might not affect the black spots, but you could damage your patio.

Find a suitable product before you apply anything.

Another alternative is to use a more natural product. Both vinegar and baking soda can remove black spots from a patio.

Simply mix white vinegar with baking soda and water to make a paste. Apply it to the black spots, and you should see it get killed off.

If you are short on vinegar or baking soda, you could look at washing powder. Mix a little with some warm water and rub it onto the black spots. Leave it for a few hours and then rinse it off. Your black spots should have then vanished!

Apply the chosen cleaner

When you apply your chosen cleaning product, it might be best to wear gloves and goggles. Even though the products may not be harmful, you’ll want to avoid getting them in your eyes or on your skin.

Generously apply the product to the black spots on your patio. Leave it for approximately 15 minutes. However, depending on what method you choose, you may need longer. If you have a store-bought product, follow the instructions on the container.

Work the product in

A simple splash of the cleaning chemical won’t be enough to kill off the black spots on your patio, so you’ll need to scrub them. Use a stiff brush and work the cleaning product into the black spots.

After an aggressive scrub, leave it for a while to fully settle in.

Rinse it away

After leaving the cleaning product to settle, you can rinse away any debris. Use your hose and aim it at the treated area. Once all the debris has washed away, you should see no trace of black spots on your patio anymore.

Allow the surface to dry off and then give it a sweep to remove any final traces.

Could I use bleach to remove black spots from my patio?

You can, but you should be careful. Bleach can be damaging to many patio surfaces as well as the plants that adorn them. It can deliver quick results in removing black spots, but it is best avoided.

Black spots can affect your patio in numerous ways. From the cosmetic appearance of your patio through to its structural integrity, black spot can be hugely damaging.

If you have left your patio untreated for too long, it might be worth considering a new patio surface. Speak to the team at Tidey and Webb, our expertise in all aspects of surfacing means we can provide you with a long-lasting, high-quality patio. We are the leading surfacing contractors for Sussex, Surrey, Kent and Hampshire, renowned for our versatile surfacing options, affordability and high standards. Get your free quote today.