What are the black spots on my patio?

patio cleaning

To answer the question, ‘What are the black spots on my patio? go straight to the section headed ‘What are these black spots on my patio? There is also a video at the end. This is a short video of our leading man Pierre De Wet, explaining the black spots and how to get rid of them.

Autumn is upon us, and this means less time entertaining in our gardens again.

Time to pack the garden furniture cushions and put the BBQ away before the winter months ruin them.

Doesn’t that sound sad… but it’s not. The beautiful smells of autumn can take over your house… cosy family nights sound amazing, don’t they?.

However, before you know it, the gorgeous weather is just around the corner, and you’ll be thinking of hosting a BBQ in the garden again.

Just one problem… you have found black spots on your patio that you cannot remove!!

‘What will you do in the summer? My friends and family will see this… you cry.

Don’t worry; there are a few things you can do. And if all else fails, your friendly patio cleaners are just a call away. You will feel proud again and ready to show off your home and garden in the summer again.

What are these black spots on my patio?

These black spots are a fungus that grows on the stone. Trees make, most of the time, the cause of these black marks and, if left on the stone, can get harder to clean.

This marking is called lichen, a fungus that usually grows on trees. It grows in the stone and is almost impossible to remove just by cleaning it with a pressure washer.

What can I do?

There are a few products available.

The Tile Master – Algo

Patio Black Spot Remover

Smart Seal – Xtreme Patio Cleaner

These products all contain high volumes of Sodium hypochlorite.

You must be aware that using these products can kill the surrounding grass or plants around the patio if contaminated, especially if you use them neat and not watered down. Also, be careful with your clothes. This product will bleach them.

I would advise asking a professional for help. Your friendly professional will know what they are doing and how to do it without causing damage to your beautiful outside features.

How do I use these products?

First, we would suggest you give the area a good clean using a pressure washer. Make sure you allow the area to dry before any next step.

Dilute the solution in a watering can (neat if the marks are bad) and work this in using a hard-brushed broom.

It would help if you kept the area wet, so remix the solution and pour this on, and you should see the solution working by now. Depending on how bad these black marks are on the patio, this may need repeating.

Then wash the solution off using the pressure washer or garden hose.

Video of our leading man, Pierre De Wet, showing you how to get rid of the black spots on the patio slabs:


Would you like to find a patio and driveway cleaning company? This may be able to help:


Patio and Driveway Cleaning Services in Cambridgeshire?


Want to know what it will cost you to have your beautiful investment well looked after? Then this is for you:

How much does it cost to clean your driveway?

Want to know what other people think about us and maybe even a few others? This is a helpful read:

Reviews about patio and driveway cleaning.

Thank you for stopping by and reading our little blog, hope this helps at least one of you with the black spots on your patio!

Edited by Tracey Gilbey, Marketing and Admin Coordinator at Art of Clean.

For further advice or information on our Carpet and Soft Furnishing care, please do not hesitate to contact the Art of Clean team on 01223 901551 in Cambridge. Our services include Carpet Cleaning, Upholstery Cleaning, oriental and area Rug Cleaning, Curtain Cleaning, Patio, and Driveway Pressure washing, Leather Cleaning, Stone and Tile Floor Cleaning, and Wood Floor Sanding and Restoration. We also supply new flooring and carpets through our sister company Art of Flooring. Our Dry-Cleaning service is provided by Farthings Cambridge