How To Clean Patio Slabs

Easily clean your patio slabs with our step-by-step guide, whether utilising a pressure washer or not.
Written By: Richard Morgan | Updated:
How To Clean Patio Slabs
Richard Morgan/DIY Works

After a wet and windy winter, your patio can begin to look weathered and require a good clean to revive its original finish. Luckily, cleaning your patio slabs is very straightforward, and it provides an instant transformation once you’ve finished cleaning it.

Unlike cleaning block paving, patio slabs are easier to clean because you don’t have to worry about sand escaping or any movement of the slabs.

If you have patio slabs that need a good clean, our guide below covers all the steps required to clean your patio with or without pressure washing.

How To Clean Patio Slabs

One of the most effective ways to clean patio slabs is pressure washing them, and in our tutorial, we used the Karcher K4, which is one of the best pressure washers on the market.

To improve the effectiveness of pressure washing, we strongly recommend purchasing a patio cleaning detergent. Karcher offers plugin detergents, but if you are using another machine, there are many formulas that you can pour/spray onto the patio beforehand.

To clean your patio with a pressure washer, follow the below steps:

  1. Remove any garden furniture and sweep the area of any loose debris.
  2. Set up your pressure washer and ensure it reaches all around your patio.
  3. Spray the detergent upon the patio slabs and leave it for 5 to 10 minutes.
  4. Rinse the detergent clear using a low-power setting.
  5. Switch to a medium power setting and use a sweeping motion to wash the patio slabs.
  6. Allow to dry before moving your garden furniture back into place.

If you want to speed up the cleaning of patio slabs, you could connect a patio cleaner attachment to your pressure washer. The Karcher T350 attachment is what we use with our machine, which not only improves the speed of cleaning but also helps to reduce dirty water spraying over the surrounding surfaces.

Before & After Results

The before and after photos below show the result of pressure washing the patio slabs. As you can see, it has made a huge difference, and it only took approximately 30 minutes to do whilst using the patio attachment with the machine. After it had dried, we sprayed a weed killer into all the joints to prevent the weeds from growing back.

how to clean patio

Richard Morgan/DIY Works
how to clean a patio

Richard Morgan/DIY Works

Cleaning Patio Slabs Without A Pressure Washer

If you don’t own a pressure washer, you can clean patio slabs using alternative methods. Whether you clean your patio with bleach, soapy water or even vinegar, it’s great for light cleaning without a pressure washer.

Regardless of the product that you use, you will also need a bucket, warm water, a bristled brush and a garden hose pipe to rinse clear the patio. Once set up, mix the warm water with bleach or soapy water and then splash it over the patio. Using the brush, scrub the patio, and you should begin to see the dirt lift from the slabs.

Once you have thoroughly scrubbed the slabs, rinse the dirty water with the hose. Depending upon how dirty the slabs are, you may wish to repeat the process for a cleaner finish to the patio.

If you wish to use vinegar to clean your patio, you will need to mix the vinegar and water in a 1:1 ratio in a bucket. You also need to pour it onto the patio and leave it for up to an hour before scrubbing and rinsing it clean with water.

How To Remove Black Spots From Patio

Patio slabs that have developed black spots on the surface can be difficult to remove, even with pressure washing. The black spots that form on the slabs are black lichen, and they feed off the minerals in the stone. As you can see from a photo taken from one of my patio slabs, they are fairly noticeable.

In terms of removing the black spots from your patio slabs, a dedicated patio cleaner is needed. Not only will they remove the black spots, but they will also help prevent the growth of new lichen.

How To Remove Black Spots From Patio

Richard Morgan/DIY Works


Cleaning your patio slabs can make a huge difference to your outdoor space, and it’s very satisfying too. Below is a video we posted on our YouTube channel that shows just how satisfying it can be, and we highly recommend giving it a go!

Whether you clean the patio with or without pressure washing, it’s a worthwhile task that keeps it looking its best. It’s also worth pointing out that the more you clean it, the easier it will be too. If you require further information about cleaning your own patio, feel free to reach out, and we will try to provide our assistance where possible.

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