Cleaning patio slabs with and without a pressure washer

Patio slabs can be cleaned either mechanically with a pressure washer or manually with a scrubbing brush, garden hose and muscle power. Read more about the topic here.

What techniques are there?

Cleaning patio slabs with a pressure washer

For large patios and heavy soiling, it is best to use a powerful pressure washer. This generates strong water pressure and can be combined with suitable attachments, saving you time and effort in this project. Even stubborn lichen and discolouration will then quickly be a thing of the past.

In addition, the cleaning interval can be reduced by adjusting the pressure. However, these advantages are also offset by purchase and electricity costs. Therefore, it may make sense to borrow the device by the hour from a DIY store or specialist shop. Also remember to keep working hours that are compatible with neighbourhoods because of the noise generated.

Cleaning patio slabs without a pressure washer

Alternatively, you can choose to clean the patio slabs manually with a scrubbing brush and a garden hose. This is particularly worthwhile for surfaces that are rather delicate and should not be exposed to high water pressure – think, for example, of sandstone, some concrete blocks and softwoods. In contrast to using a high-pressure cleaner, this also saves water, electricity and any initial costs.

With this variant, it can be helpful to fix the water hose to your scrubber or broom with some tape. This way you have both hands free to use your pure muscle power for cleaning. In addition, the grout material is protected, as the risk of rinsing and swirling is significantly lower.

Product recommendations

To treat patio slabs with a high-pressure cleaner, you should opt for a device with a pressure of at least 100 bar and a surface area capacity of more than 40 m2/h. Also opt for a joint scraper made of hardened metal. For oil and grease stains, we recommend a special cleaner that can be applied during preparation.

Wolf Scraper Kf-2K

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Last update was on: August 13, 2022 12:13 pm

This crevice scraper can be connected to different handles and grips with a click system, so you can choose the perfect option for maximum user comfort. It is made of hardened metal and features a particularly sturdy blade.

Wet & Forget - Mould Lichen & Algae Remover (5 Litre)

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£26.98 £34.99

This special cleaner can be used for oil and grease stains on absorbent and non-absorbent surfaces. It is suitable for both natural stones (such as marble and granite) and synthetic variants (such as concrete slabs or ceramics). The oil and grease remover absorbs and binds the stains so that they can be easily swept away after a short reaction time.

Kärcher K2 Premium Full Control Car and Home Pressure Washer

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At 3.8 kg, this high-pressure cleaner not only offers a mobile weight, but also impresses with a high operating pressure of 110 bar and a powerful flow rate of 360 l/h. The surface area is specified with 20 m2/h and combined with a maximum inlet temperature of 40°C. The area output is specified at 20 m2/h and combined with a maximum inlet temperature of 40°C. In addition, the unit has a time-saving clip-in and clip-out mechanism for the high-pressure hose.

Kärcher T 5 Patio Cleaner - Pressure Washer Accessory

Last update was on: August 13, 2022 12:13 pm
£67.50 £85.99

You can use this surface attachment to match the pressure washer, which distributes the water jet optimally and is gentle on the patio surface. The attachment can be combined with various devices that allow an operating pressure between 20 and 180 bar as well as a maximum flow rate of 600 l/h. The generous area output of this cleaner attachment is 60 m2/h.

Instructions: Cleaning patio slabs in 3 steps with the pressure washer

Total Time: 2 minutes


Cleaning patio slabs without a pressure washer

In order for the water jet of the pressure washer to work optimally, the terrace should be prepared beforehand for the actual cleaning. Sweep up all leaf and sand residues with a broom and moisten the surface. The joints and particularly heavily soiled areas as well as grease stains should also be pre-treated accordingly:

Joint cleaning. Use a joint scraper or a joint brush to remove moss, lichen and weeds from the spaces between the patio slabs. If the unwanted plants have roots, these must also be scraped out. Otherwise the green growth will always return, which increases the amount of work required for subsequent cleanings.

Removal of coarse dirt. The next step is to get to grips with coarse dirt – for example, places where you can no longer see the patio covering under dirt crusts. For this, it is worthwhile to use scouring sand, which can be rubbed over the surface with a broom. The small sand particles break up the dirt crusts, making them easier to remove with the pressure washer.

Use a patio cleaner. Oil and grease stains on the patio floor should also be pre-treated, for which special cleaning agents are available. These often only need to be applied with a spray bottle and left to work for a short time to soak up the mineral and synthetic oil residues. Afterwards, the stain can usually be washed or swept away.

Cleaning with a pressure washer

Cleaning with a pressure washer

Use a suitable attachment. Then it is the turn of the pressure washer. It is best to choose a surface attachment that distributes the water jet over several nozzles and increases the contact surface. This also protects the material and reduces water consumption. The joint material is also less swirled and rinsed out, which can sometimes save the very last step of these instructions.

Clean row after row of stones. Work with the pressure washer row by row to get an even result. Use a pH-neutral soap or a gentle special product for your patio material as a cleaning agent. Aim the pressure washer only at areas from which the water jet cannot be diverted to the rest of the garden. Your back should be facing the wall of the house.

Seal patio slabs

Seal patio slabs

Apply stone finish. After cleaning, it is worthwhile to impregnate or seal the patio slabs. This prevents dirt from accumulating again and protects against moisture and weather. For example, a stone finish can be used as a sealant, which should be adapted to the material of your decking. Apply it in even layers.

Allow the stone finish to dry. The stone finish must then be allowed to dry for a sufficiently long time in order to develop its full effect. Follow the manufacturer’s instructions regarding the drying time and do not walk on the terrace during this time. It is also important to find the optimal time for sealing – there should be no rain, snow or frost.

Split, sand or special jointing material. In a final step, the joint material should be filled. Split, sand or grout are suitable for this. Grit is the best moisture-dissipating material, but is only suitable for rather wide joints. Sand washes away quickly, but absorbs tension from the patio slabs. Grout prevents weed and moss growth, but can have negative effects on the environment.


  • High pressure cleaner with surface attachment
  • Joint scraper or joint brush
  • Broom
  • Scrubbing brush or rubber squeegee

Materials: Soapy water or cleaning agent for the decking material, Stone sealant, Water, Grouting material, possibly scouring sand, possibly oil and grease cleaner

Possible problems & solutions

Preparation problems. During preparation, you may come across a number of dirt and stains that quickly become problematic for the scrubber or pressure washer – think, for example, of grease stains from the last barbecue or lichen and weeds on the pavement. These should be pre-treated with special products and scraped out with a joint scraper.

Cleaning problems. When working with a high-pressure cleaner, it can quickly happen that you cause soiling on the surrounding house walls or that the stones are damaged. On the other hand, keep your back to the house and make sure there is a distance of at least 20 cm between the dirt cutter and the decking.

Problems regarding the cleaning agent. A chemical cleaning agent is not always the best choice, but can instead cause environmental pollution. Therefore, weigh the costs and benefits before using it, and be sure to strictly follow the application instructions. Alternatively, there are some home remedies for patio cleaning that are gentler and prevent this problem.

If the patio has not been cleaned for a long time or if the weather has caused particularly stubborn dirt, even the use of a pressure washer is sometimes no longer sufficient. In such cases, you can decide to hire professional help or rely on an industrial pressure washer. Such equipment can often be rented cheaply from specialised dealers.


How are natural stone patio slabs cleaned?

Natural stone slabs have a porous surface structure, which is why a pressure washer should not be used when cleaning this material. Instead, use a soft root brush and pH-neutral special cleaner. Avoid cleaning agents with surfactants, acids and scratching ingredients altogether.

How can the joints between the patio slabs be cleaned?

To remove lichen, weeds and the like from the joints, it is worth buying a joint scraper with a hardened metal blade. This has a curved shape so that you can reach deep into the joints. Many models are also combined with a grout brush.

Which product is suitable for cleaning patio tiles?

Depending on the material your patio slabs are made of, different cleaning agents come into question – so always match your choice to the covering. In addition to special cleaners and pH-neutral soap, soda, baking powder and dishwashing detergent are also suitable.

What is the best way to clean patio slabs?

Patio slabs can be cleaned with or without a pressure washer. Scrape out the joints and remove coarse dirt and stains before using a pressure washer or scrubber to clean the entire surface. Then seal the terrace with a stone finish and fill the joints.

Ray D Berryman

Ray D Berryman

My goal is to help you choose the best and highest quality pressure washer. Choose a pressure washer based on your needs.

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