When most people think of pressure washing, they envision high-pressure water jets blasting away dirt and grime. However, there's another technique that’s become increasingly popular—soft-washing. It uses low-pressure water combined with specialized cleaning detergents to gently clean delicate surfaces without causing damage. But can you use a traditional pressure washing machine to soft-wash? The answer might surprise you.

1. What is Soft-Washing?

Soft-washing is a cleaning method that utilizes low-pressure water (usually under 1,000 PSI) and effective cleaning solutions to safely clean surfaces like roofs, siding, and decks. The technique is highly favored in the United States, where it's extremely common due to its ability to remove harmful algae, mold, mildew, and other biological growths without damaging fragile materials. It's gentle yet highly effective, making it the go-to option for surfaces that could be harmed by the intense force of traditional pressure washing.

Recently, soft-washing has been gaining traction in other parts of the world, especially Europe. The method is becoming more recognized in regions with delicate stone, tile, and roof materials, where traditional pressure washing could lead to costly damage. As soft-washing spreads globally, it’s starting to change the way professional cleaning is done in many countries.

2. Adjusting the Pressure: The Worst Option (Don’t Do It)

One of the first things people think about when trying to use a pressure washer for soft-washing is simply lowering the PSI (pressure per square inch). While this may seem like a reasonable option, it is the worst approach for achieving a successful soft-wash. Here's why you should never adjust the pressure yourself without professional help:

• Risk of Damaging the Machine: Lowering the pressure on a pressure washer without the proper adjustments can cause strain on the motor, pump, and other internal components, potentially damaging the entire machine. Not only could this lead to expensive repairs, but improper adjustments may void the warranty or lead to premature equipment failure.
• Inconsistent Results: A machine not designed for soft-washing may still output water at inconsistent pressures, which means you could end up with areas that are too harsh or not cleaned properly.

To avoid these issues, always rely on a dedicated soft-wash system or read on to figure out how to use your pressure washing machine to soft-wash the correct way, ensuring you don’t harm your equipment.

3. Using the Right Nozzle

When soft-washing, you’ll need the right nozzle to ensure the water pressure remains low enough to prevent damage to surfaces. While many pressure washers have adjustable nozzles, you’ll want to choose a wider nozzle that disperses the water in a larger area, minimizing the force.

However, did you know you can also use a 0-degree nozzle with the right technique? Specifically, a shooter tip is ideal for this job, which allows for a more focused yet gentle spray, making it perfect for soft-washing jobs. When using a shooter tip, always stand back from the surface you're cleaning and sweep the nozzle from side to side at an angle. This method ensures the cleaning solution is applied effectively, while also preventing damage to the surface.

View Our Shooter Tips Here

By spraying at an angle / distance and using the right technique, you can get the cleaning power needed without the force that could cause harm. Remember: soft-washing is about spreading out the cleaning solution evenly, not blasting it at high pressure.

4. Using the Right Detergents

The real magic behind soft-washing lies in the specialized cleaning solutions, which are designed to kill algae, mold, mildew, and other organic growths. The most commonly used chemical in soft-washing is sodium hypochlorite (bleach), which is effective at breaking down these biological growths at the root, preventing them from returning.

When soft-washing, you’ll want to ensure that sodium hypochlorite is your primary cleaning chemical.

• Adding Surfactant: Surfactants are crucial to enhance the effectiveness of sodium hypochlorite. They help with the foaminess, allow the chemical to "stick" to surfaces longer, and help you track where you've sprayed. Surfactants also help reduce the strong chlorine smell that sodium hypochlorite can produce.

Using the correct detergent blend ensures you not only clean the surface thoroughly but also prolong the cleanliness and prevent future growth for a longer period of time. View Our Surfactants Here.

5. The Soft-Wash Setup: You Cannot Convert a Pressure Washer to Soft-Washing

When it comes to soft-washing, you cannot simply convert a traditional pressure washer into a soft-washer. A proper soft-wash system includes a proportioner that carefully mixes the exact ratio of sodium hypochlorite, water, and surfactant. These systems are designed to deliver the right chemical balance at low pressure for safe and effective cleaning.

Without a proportioner, it’s difficult to maintain the consistency of the cleaning solution, which could either dilute the chemicals too much or cause overly concentrated solutions that can damage surfaces. If you want to perform soft-washing safely and effectively, investing in the correct soft-wash setup is essential. Cleaning vinyl with a pressure washer however does work as generally, a chemical injector will achieve the perfect SH ratio.

6. Wood Decks: Why Soft-Washing is Key

Wooden decks are a common surface that benefits from soft-washing. High-pressure washing can easily splinter and damage wood, especially softwood or older decking materials. Soft-washing, on the other hand, allows you to clean the deck gently without harming the surface.

For wood decks, soft-washing typically uses a mix of sodium metasilicate and oxalic acid to not only clean but also help neutralize the effects of previous high-pressure washing (if any). These chemicals can help brighten and rejuvenate the wood, while also protecting it from further damage.

By using soft-washing, you ensure that your decks remain in top condition without risking the integrity of the wood. It’s an ideal solution for both residential and commercial properties that want to keep their outdoor spaces looking great.

Conclusion: Soft-Washing with a Pressure Washer?

In conclusion, while it is technically possible to use a pressure washing machine for soft-washing, it’s a great option for those starting out who cannot yet invest in expensive, dedicated soft-wash equipment. By properly using a pressure washer for soft-washing homes and roofs, it allows you to get the best of both worlds with pressure when needed such as concrete, and a low pressure cleaning such as vinyl siding. As mentioned however, you can’t simply adjust your pressure washer’s PSI to achieve soft-washing results, and using the wrong nozzles or chemicals could lead to poor performance or damage.