How To Clean Paving Slabs With Bleach & Water

How to clean paving slabs with bleach and water
Dirty paving slabs

We take a look at how to clean paving slabs with bleach and water. This method of cleaning paving slabs with bleach and water requires no power washing afterwards.

It answers the question we get asked frequently on How to clean paving slabs with bleach and water without using a jet washer?

This method is a cheap, simple and effective way of keeping your paving slabs clean. Making your paving slabs algae, moss and weed free.

We are not going to use specialist cleaners to keep our paving slabs clean, we are using a cheap-to-buy bleach that you can buy from most supermarkets and local shops. You don’t even need to buy an expensive bleach. The bleach we bought to clean our paving slabs cost us just 0.69 pence per bottle and we only used the one bottle to clean the slabs.

If you don’t want to use bleach to clean your paving slabs you could use specialist ‘apply and leave’ patio cleaners to clean you paving slabs. These type of cleaners are not made from bleach. We have a list of the 6 best-selling ‘apply and leave’ patio cleaners with reviews and star ratings that you can view here if you prefer to not use bleach to clean your paving slabs.

Caution should be shown when using bleach to clean your paving slabs!

Cleaning your paving slabs with bleach and water is very effective at removing and cleaning moss, algae, and weeds from paving but it is not for everybody! All paving slab types are different. I would not recommend that you use bleach to clean your paving if any of the following apply to your paving.

  • Your paving slabs or block pavers are made from man-made coloured concrete. The bleach could fade your paving if constantly cleaned with bleach over a long period of time. If this does not concern you then you should be fine to clean concrete block paving with bleach.
  • If there is a run off of the bleach and water solution towards a garden area or soil border. This is because bleach will kill all plants and greenery. So make sure that if you do use bleach that there is no chance the cleaning solution will run onto lawn grass area or planted garden border. If you cannot avoid a run off of bleach and water towards an area of lawn or border area I would recommend that you first wet any green area to lessen the chance of killing the grassed or planted area. Then rinse with plenty of water afterwards.
  • If you have natural stone paving slabs or grey concrete man-made paving slabs and the run off of the water is not a problem then you should be fine to clean your paving slabs with bleach and water.

The official name for bleach is Sodium Hypochlorite. You can find industrial strength sodium hypochlorite for sale for cleaning many surfaces besides paving slabs and block paving. These surfaces include commercial and private swimming pools and agricultural buildings where livestock is kept. Paving is often cleaned commercially with sodium hypochlorite by many cleaning companies because it quick and effective.

Lets look at how to clean paving slabs with bleach and water

You can watch a quick 2 minute video on how to clean your paving slabs with bleach and water. Or simply follow the easy to understand step-by-step instructions with photos below the video.

Step-by-step instructions on how to clean paving slabs with bleach and water.

Please follow these simple instructions to get clean and weed free paving slabs.

Remove all patio furniture before cleaning with bleachRemove all patio furniture

Begin by removing all patio furniture and plant pots from the paved area we are going to clean with bleach.

Any items that are unmovable such as large pots or planters should be covered with fleece or sheeting to stop the bleach damaging and killing the plants from slashes.

Sweep the paving slabs to remove all loose dirt Sweep clean the area to remove all loose dirt

Sweep the whole paved area clean to remove any loose dirt. Our paving slabs were covered in rotting leaves and old weeds.

Pick out any larger weeds as you sweep the area. You could use a weeding tool to remove the weeds or just pull them out by hand. It depends how infested with weeds the paving slabs are. Smaller weeds that are difficult to remove may be left as the bleach will kill these weeds when applied.

Wet the patio paving slabs with water and sweep away loose dirtWet the patio slabs with clean water

The whole area of paving slabs need to be wet before we apply the bleach and water solution. You should rinse and sweep away any loose dirt as you wet the area of paving slabs.

Make sure you wet the areas into the corners of the patio.

Mix the cleaning bleach with 5 parts of water and apply to the wet paving slabsMix the bleach with water in a watering can

Next we need to mix the bleach and water. We have used a 5-1 mix. That means that we have used 1 measure of bleach to 5 equal parts of water.

You can vary the strength of the cleaner by mixing more bleach or more water depending on how dirty the paving is. But a mix of 5 – 1 should be sufficient to clean and kill weeds and algae on most patio paving slabs.

Apply the bleach cleaner to the whole surface brushing all over to give equal coverageApply the bleach and water to the wet paving slabs

Next apply the cleaner to the surface and brush all over to make sure you get an equal coverage of the cleaner.

Make sure you brush the cleaner into all corners of the paving slabs.

Once applied leave the cleaner on the surface for 15 minutes.

Rinse off the bleach cleaner after 15 minutes with clean waterRinse off the cleaner

After leaving the bleach cleaner on the surface for 15 minutes begin to rinse off the cleaning solution with clean water.

It will help if you brush the surface as you rinse with water. Don’t worry if you don’t remove the whole cleaner. It won’t do any harm if you do leave small amounts on the surface.

IMG_0425Notice how clean the paving slabs are

Once you have finished rinsing the cleaner off the surface you will begin to notice how clean the paving slabs now are. All the moss, weeds and algae have now died and the paving slabs are left beautifully clean.

You should not have to re-clean the paving for at least a couple of months.

Your paving slabs should now be clean, weed and algae freeReplace patio furniture

Finish off by replacing the patio furniture and any plant pots you removed earlier.

You now have perfectly clean patio paving slabs that are free from weeds and algae.

All for the cost of a bottle of 0.69 pence bleach and a couple of watering cans of water.

I hope this helps if you wanted to know how to clean paving slabs with bleach and water. Let us know if you have had success with this method of cleaning, or send us your photos or comments and we will share them with everybody.

Helpful articles on cleaning block paving without using bleach


  1. Was looking for information right along this line. I’ve run into some customers that ask about a simple way to clean slabs in their yards and usually mention a pressure washer. Most of them don’t want to invest in one. Thank you for this post. I will be suggesting your method and site to them from now on.

  2. Works every time for me. I have a large patio 5m x 12m so need to keep looking nice and clean. Just cheapo bleach is sufficient, no need for the posh stuff. Sometimes if it starts raining I mix up several buckets of hot water and bleach and through this over patio and then let mother nature finish off the rest apart from a quick broom with a stiff brush. After 5 years since patio was laid this still looks brand new.

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