How to soft wash using a pressure washer
Peter Sitkowski | 8th May 2023 | 6 minutes to read
When most people think of pressure washers, they think of pumping up the PSI and blasting surfaces with jets of water that’ll strip off dirt and grime. While this is a fantastic way to remove stubborn dirt from your workshop or home, the power of a pressure washer can often come with some undesired effects. This is where soft washing comes in.
Below we look at the specific uses for soft washing and how to soft wash effectively:
What is Soft Washing?
Soft washing uses a pressure washer to pump out high volumes of water at around 500-600 PSI, using cleaning solutions rather than raw power to remove mould, bacteria, and mildew from surfaces.
What are the Benefits of Soft Washing?
Soft washing works in a slightly different way to high-pressure cleaning and it has some serious benefits when done correctly.
Prevents Damage
There are times when you need high pressure water to get a cleaning job done, but you can also cause damage to a surface by using a pressure or power washer on it. Soft washing has the benefit of offering up more PSI than your average garden hose for extra reach, while still being delicate enough to avoid stripping loose paint, breaking gutters, or knocking shingles off your roof.
Removes Mould and Mildew More Effectively
The lower pressure also allows the soaps and solutions to sit on your surface better and to seep into areas where mould and bacteria might grow, slowly breaking it down until it dissipates entirely.
Safer and Easier
Pressure washing generally requires you to get close to the surface you are trying to clean, because the jet of water is what is doing the work. With soft washing, you’re still using enough PSI to get a lot of height out of your pressure washer, which means you can clean your entire house from ground level, without the use of ladders or scaffolding.
The water you’re using is also at a low enough PSI that if you spray your hand or foot with it, or accidentally hit the family dog with a jet of water, you’re a lot less likely to cause injury.
Save Money and the Environment
Another major benefit of soft washing is that it uses a lot less water because you’re not constantly in need of high-pressure water to clean with. This makes it a lot more cost-effective and better for the environment as well!
How do I Soft Wash Properly?
There are several various tools and equipment you’ll need in order to perform a proper soft wash.
Pressure Washers vs Power Washers
The first thing you’ll want to figure out is which kind of washer will be best suited to the job. There are differences between power washers and pressure washers, with the former having a heating element that produces hot water and the latter simply relying on high pressure to clean.
With soft washing, a pressure washer will do the job, as the high heat of a power washer can be harsher on surfaces and on your plants and garden, and since we’re not cutting through any grease or tar here, the cold water will be fine.
You’ll also want to choose between a petrol or electric pressure washer. Both have their benefits for power cleaning, but since petrol pressure washers are usually for jobs that require incredibly high PSI, an electric unit will do the job here.
Getting the Right Chemicals
The main thing you’ll need as part of your cleaning solution for soft washing is bleach. A solution of 3 parts water to 1 part bleach will provide you with the right balance to kill pesky bacteria and remove mould without issue.
Check your manual or ask in-store to make sure that your pressure washer is suitable for a bleach solution.
The next thing you’ll need is a surfactant, which is a type of chemical that you’ll find in detergents and soaps. Surfactants are necessary for soft washing because they help the cleaning solution cling to surfaces and spread out evenly, as well as permeating through grime and loosening dirt.
You’ll want to use a professional cleaner that is designed for use with a pressure washer. For instance, if you’re using a Karcher Pressure Washer, you can pick up Karcher Universal Cleaner which is specially formulated to work with Karcher products and is designed to cling to surfaces better than regular dish soap, thus providing a more efficient clean.
Because you’re using bleach, make sure that any detergent or cleaner you use is free from ammonia or hydrogen peroxide as mixing bleach with these chemicals can cause serious injury.
If you’re washing your home and worried about runoff damaging your plants, you might want to get a neutraliser, which you can apply to your plants and surfaces after soft washing to neutralise the cleaning solution and provide protection for your garden.
Using the Right Nozzle
As mentioned earlier, soft washing is performed within the 500-600 PSI range, making it much lower pressure than the usual 1300-3000 PSI you’d normally be wanting from a pressure washer.
When it comes to nozzles, you’ll want to change your nozzle depending on much power you want, with 0° being the most powerful and 65° nozzles usually having very little pressure and being used for dispersing soap for car washing and other low-pressure clean-ups.
Pressure washer nozzles will generally be colour-coded, so look at your pressure washer’s manual to see which spray pattern each nozzle produces.
In the case of soft washing, you’ll want to stay within the 25° to 40° range in order to make sure you aren’t outputting too much pressure.
Soft Washing Your Home or Other Surface
Whether you’ve got a grimy rooftop or a vinyl or stucco surface to clean, the main principals are the same.
Protect Your Plants
For soft washing your house, the first thing you’ll want to do is use clean water to pre-wet any plants or shrubbery that touches the house to help to protect them from the soft washing solution.
Add Your Solution to the Washer
If you’ve got a pressure washer with a built-in soap dispenser, then add your soft washing solution to the pressure washer, otherwise you’ll need to apply your solution manually using a bucket and brush. Attach the correct nozzle, set the PSI to around 500 if you have a dedicated valve, and turn your pressure washer on.
Start Spraying
Next, spray across the surfaces in 5 metre sections to make sure you cover everything, using the higher-pressure 25° nozzle for the walls and roof and the 40° nozzle for your windows.
Leave to Soak
Once all surfaces are properly covered in the solution, leave it to sit until any plant matter or algae starts to fade or for approximately 5-10 minutes to allow the chemicals to do their work. It’s best that you don’t leave the solution to dry, as it can cause damage to surfaces if left to sit for too long and will leave streaking, so you’ll need to be particularly mindful on hotter days.
Rinse Thoroughly
Now that the solution has done its job, hit the surfaces with clean water in order to rinse the solution off. Make sure you get all the solution rinsed off and keep the pressure at the same PSI as you had it for initial application.
Neutralise
If you’re particularly worried about your plant-life, give it a rinse with a neutralising agent to make sure the solution won’t damage your garden.
Enjoy Your Pristine Surfaces
Now that you’ve learned how to soft wash, you’ll appreciate how much less hassle this method can be than using focused pressure washing to clean surfaces, and how much better it is for your roof in particular.
With a ton of pressure washers for sale at Repco, as well as nozzles and cleaning accessories, we’ve got solutions to all your cleaning needs, whether it’s for your car, home, or workplace.
