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15 Apr 2024

Five things you should never do with a pressure washer

Plus expert tips on how to get the best from your pressure washer when cleaning your patio and car

Verity MannPrincipal researcher & writer

Spring's here, which means it's time to get your patio and decking ready for entertaining outdoors, and your car and caravan dirt-free before hitting the road. A pressure washer can make quick work of it all, but how do you avoid causing damage?

Pressure washers work by blasting surfaces with a high-pressure jet of water and are a great way of removing ingrained grime from patios, decking, cars, caravans and garden furniture. It's important to use them correctly, though, as the jet is strong enough to damage car paintwork or delicate woodgrain in decking.

Our top tips on what not to do will help you use your pressure washer with confidence and make sure you get the cleaning results you want.

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If you haven't already got one or you think you might need an upgrade, take a look at our pressure washer reviews.

Don't choose the wrong setting

Basic pressure washers come with just one lance and nozzle. But more expensive models can come with several that have different strengths and shapes of jet spray. These include:

Variable-fan jet - ideal for cleaning delicate surfaces, such as cars, decking or chipped areas of patios, as they allow you to vary the force of the jet from a focused point to a gentler broad fan.
Rotary jet - best for blasting ingrained dirt from patio slabs, but far too strong for delicate surfaces such as cars or decking.
Angled lances - use for cleaning the underside of cars and garden furniture.

If your pressure washer only has a fixed jet, move it further away from the object you're cleaning to reduce the force of the spray and avoid damage.

Don't forget to use a patio-cleaning attachment

A patio-cleaning attachment has a plastic hood with a brush around the bottom edge which helps reduce the amount of dirty water flying around. Inside the hood there are a pair of jets that rotate at high speed close to the ground to blast off the dirt.

If you're cleaning your patio, always try to use a cleaning attachment. It not only saves you time and makes the job easier, but we also found we stooped less when using one.

Some washers come with a patio-cleaning attachment included. But if it doesn't, you can usually buy one for around £50

Want to know more? Check out our guide on pressure washer attachments.

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Don't wear shorts and flip-flops

No matter how carefully you use your pressure washer, you're more than likely going to get wet and dirty.

Avoid wearing open-toed shoes or flip-flops - instead invest in a good pair of wellies and some waterproof trousers to help keep your clothes clean.

Don't directly blast water at your car

Rather than just trying to spray off the dirt from your car and risk damaging the paintwork, tackle the job in several steps.

Make sure your car isn't parked on gravel or you could blast the stones on to the car and damage it.
Start by rinsing off the top layer of grime with a jet about 5-8cm wide; wider still on fragile areas, such as windows.
Apply a detergent and allow it to work its magic for a few moments. Don't let it dry or you could be left with marks that need to be buffed off by hand.
Loosen the grime, preferably with a brush attachment. Do the wheel arches last as any small stones trapped in there could get into the brush fibres and scratch the paint elsewhere.
Rinse off the dirt to finish. If you have a fixed-jet model, stand about a metre away from the car to avoid damaging the paintwork.

Watch our video on cleaning your car with a pressure washer.

Don't use it to remove weeds from patio

You'll risk removing the mortar between the slabs.

Instead pull them out by hand - an old blunt knife is perfect for prising out the roots from tight gaps. You could also try a long-handled patio brush, which has a narrow, wire brush that's ideal for getting into the cracks between slabs, or a patio knife

Once you've got rid of the weeds, watch our video on cleaning your patio with a pressure washer.

Where to buy a pressure washer

While there are lots of cheap pressure washers for under £100, they tend to be cheaply made and don't have enough power to blast away the toughest grime. If you're unsure of which pressure washer to buy, you can consult our expert pressure washer reviews to see which models have powerful streams, and which ones barely trickle.

Some popular online retailers that sell pressure washers include:

Should I buy a Karcher pressure washer?

Some of the most popular pressure washers are made by Karcher – like the K2 Compact and K4 Power Control - which retailers like Screwfix and B&Q claim are top sellers.

If you want to learn more about how Karcher pressure washers perform, you can read our guide on which pressure washer brand to buy.

If you'd like to view Karcher pressure washers, you can visit their website.

Below, you can view the pricing and availability of the Karcher pressure washers we've tested: