Chemicals and Pressure Washing

Beginners often make the common mistake of using as much pressure as possible to clean the dirt and algae off the surface being cleaned. Cleaning this way often results in damages and ends up taking much longer to clean the surface. Smart contractors use the right chemicals for the job at hand and let the chemicals do most of the work for them.

Power washing is a combination of four steps, agitation, breakdown, lift and rinse. The pressure of the water is what provides the agitation of the dirt from the surface. The chemical application then causes a breakdown of the dirt, oil, algae etc. The lift is a result of the surfactants in the chemicals separating the dirt from the surface. Last of all the water rinses away the dirt so it doesn't settle back onto the surface.

If you were to accomplish all of these steps with water pressure alone, it would be time consuming and likely result in surface damage.

As a general rule of thumb, if the type of soil you are cleaning is dirt or algae then you should use an alkaline cleaner. If it contains minerals such as rust then you should use an acid cleaner. Some examples are Power House which is an alkaline cleaner, and ProBRC which is a common acid cleaner.

For a list of different chemicals you can use for each job and or surface type you may encounter in the field see the table on the Pressure Washing Surfaces page.

Material Safety Data Sheets (MSDS)

A Material Saftety Data Sheet is required under the OSHA Hazard Communication Standard. The MSDS is a detailed document prepared by the manufacturer or importer of a hazardous chemical.  It provides information such as potential health and physical hazards of the chemical and the emergency & first aid procedures in case of exposure.

It is required by OSHA to have a proper MSDS for each chemical you use while on the job. Being cited by OSHA for not having a proper MSDS can result in a hefty fine. Here's an example of a MSDS to give you an idea of what this form looks like.