Power Washing or Soft Washing: That is the Question

Heidi ho my house washing Homies. I am here to dispel some confusion and to bring some clarity to your understanding. What is the difference between power washing and soft washing, you ask? Well, the obvious difference is in the name. Power washing uses a high-pressure stream of water to blast dirt and growth from surfaces. Whereas soft washing uses a gentle stream of water with solution to clean and kill surface growth.

Perhaps we could say that soft washing is latest evolutionary form of power washing. Power washing does a very fine job of removing visible surface contaminants from roofs, siding, sidewalks, driveways, etc. However, power washing does have its downside, the biggest one being the danger of damaging the surface that is being cleaned. Power washers operate between 2000 and 4500 psi. To give you an idea of how powerful that is, a garden hose operates at about 40 psi. Power washing a surface, (especially a softer surface, such as wood, siding, etc.) with too much pressure or with the wrong tip, can cause irreversible damage to the surface.

As a matter-of-fact, several years ago, I created a brief video demonstrating the power of a small power washer. In the video I literally cut a 2 x 4 in half within about 30 seconds. As you could probably imagine, a power washer could be dangerous humans and pets as well. Nevertheless, in the hands of a professional, power washing can do an amazing job at cleaning dirty surfaces. 

This brings us to soft washing, which is a gentler way to clean surfaces that may be damaged by the intense pressure of power washing. Soft washing uses low pressure (100 psi) with a mild cleaning agent containing bleach and surfactant (soap). The cleaning agent is carefully mixed and diluted to just the right strength to kill the unwanted green and black organic growth on surfaces but not kill your plants. One of the first things we do when we start a soft washing job is wet all the plants and grass in the area with plain water. The cleaning solution is applied to the surface and then rinsed with plain water. We work in sections, cleaning then rinsing, so if any overspray hits the plants they are already wet and then rinsed when the surface is rinsed.

Some ask about what the cleaning agents do once they are in the soil. The cleaning agent is heavily diluted, then diluted more when rinsing, so very tiny quantities of soap and bleach may enter the soil. The bleach quickly breaks down into a simple salt and does not cause any damage.

Even with such a tiny concentration of cleaning agent, soft washing does a fabulous job at removing and killing microbial growth such as algae and mold. Whereas, power washing does not kill organic growth. So, a good soft washing job will look as good or better than power washing but with less potential for damage to your surfaces, very little environmental impact and since the organic matter is killed it won’t grow back as fast.

It’s important to hire a professional when washing surfaces around your home to determine the best washing method for your surfaces and ensure damage-free cleaning. When soft washing, expertise is critical for using the proper ratios of water and cleaning agent to ensure plants and grass are not damaged.