Having your siding cleaned 25 years ago usually meant brushes and ladders…and a weekend. By the late 90’s, most homeowners (and contractors) had switched to high pressure cleaning the exterior of homes. While this shortened the time spent from an entire weekend, it still took the better part of a day to clean an average sized two story home.
The problem with pressure blasting the dirt and algae off is that you had to apply the water pressure equally across the entire surface or you would cause “wanding” marks. These marks are generally made due to the left to right sweeping motion and start and stop points. As you sweep from left to right, the distance between the tip and the surface changed, resulting in different spray patterns, water volume and surface pressure.
Besides the time required to high pressure clean an entire home, there is the issue of damage. Many manufacturing processes today use water jets to cut rock and steel. While the pressures are much greater than that of a pressure washer, the principles are the same. In the worst case, the damage is quite obvious and visible. In any case, some degree of surface is scoured and possibly removed. In other words, high pressure is not the ideal method to clean the exterior of your home.
There have been huge changes in the technology of house washing in the last decade. Most professional exterior cleaners now use a soft washing method for house washing. While similar to soft washing a roof, the detergents are different.
It’s a lot like your laundry detergent
When you toss your clothes in the washer, it doesn’t “pressure wash” your shirts and pants. All the machine does is provide a gentle agitation and a rinse cycle. The detergent does the work and there is a science behind it.
Basically, what happens when the house wash detergent is applied to your siding, the surfactant molecule attaches on one end to the water (red) and on the other end to the dirt (yellow). Having lost it’s bond to the surface and with the assistance of wetting agents and a light agitation (the low pressure rinse), the dirt flows right off the surface of your home.
While we use a pressure washer for the application of the detergent as well as the rinse step, we use “rinse tips”. These tips and the volume (gallons per minute) of our machines allow us to reach the upper levels of the home without the need for ladders.
All of our trucks are equipped with the soft wash systems and our crews are trained in the soft washing methods.