How To Clean Paving Slabs With Bleach & Water

How to clean paving slabs with bleach and water. You can see why our dirty paving slabs need to be cleaned.

We take a look at how to clean paving slabs with bleach and water.

You can also use this method to clean block paving, concrete and concrete & stone slabs.

It answers the question we get asked frequently on paving.org. How to clean paving without using a jet washer?

This method is a cheap, simple and effective way of keeping concrete, paving slabs & block paving clean that’s free from algae, moss and weeds.

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 £0.69p per bottle and we only used the one bottle to clean the slabs.

Caution should be shown when using bleach for cleaning

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 colored 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.

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.

Watch our quick video on 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. The method we have shown if for cleaning natural stone paving slabs. You could also use this method for cleaning concrete or clay block paving with bleach and water.

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

Please follow the instruction below on how to clean paving slabs with bleach & water to achieve perfectly clean and weed free paving slabs.

Remove all patio furniture & pots

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

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


Sweep clean the area to remove all loose dirt

Sweep the whole paved area 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 weed removal 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 slabs with clean water

When the area to be cleaned has been swept and any loose dirt & weeds have been removed, the whole area to be needs to be wet before we apply the bleach and water solution.

You should rinse with clean water. As you wet the area, sweep away any loose dirt.

Make sure you wet all the area. Pay particular attention into the corners of the patio.


You can use a watering can or any suitable container to mix the bleach and water.

Mix the bleach with water

Next we need to mix the bleach and water. We have used a plastic watering can but you could use any suitable container such as a plastic bucket or mop bucket.

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, moss & algae on most types of patio paving slabs.


Apply the bleach and water to the wet paving slabs

Next apply the cleaner to the paved surface. Brush the solution 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 10 -15 minutes.

Rinse off the cleaner

After leaving the bleach cleaner on the surface for 15 minutes begin to rinse off the surface of your paving with clean water.

It will help if you brush the surface as you rinse with water

if you have pets that walk on the paved area, I would recommend rinsing the area until you remove all the bleach from the surface before allowing your pets to reuse the area.


Patio paving has now become clean and no green algae or moss remains

Notice how clean the paving slabs are

Once you have finished rinsing the surface with clean water you will 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.


Once your patio is clean you can replace patio furniture

Replace any 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.

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

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.


Helpful articles on cleaning block paving without using bleach

2 comments

  1. How long after this process do you have to wait to allow pets back into the area? I have a dog so am wondering how long I will need to wait after everything dries before he can walk on the surface again

  2. Hello Danielle,
    As long as you have rinsed all the bleach from the surface it should be fine to allow your dog to walk on the area again.

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