Pressure Washing Techniques

Pressure Washing Techniques
  • When pressure washing always fog or presoak the surface with a detergent, degreaser, or chemical presoak. Presoaking reduces wash time and chemical cost
  • Hot water is a better solvent than cold water
  • Always rinse detergent off the surface before it dries
  • Commercial contractors generally use 4 to 6/gpm at 1500 to 3,500/psi for most cleaning applications. An exception to this is wood cleaning. Here 500 to 2,000/psi is preferred with chemical cleaning to reduce the furring of the wood. Water flow rates of less than 4 gallons per minute- found on general consumer (homeowners) units- are not high enough to be competitive because of increased cleaning time, which raises labor costs. 
  • Chemical dilution is largely a matter of personal preference. For most mobile power washing work, chemical costs run from three to five percent of gross sales, labor accounts for 30 to 45 percent, and fuel for heat is two to four percent. If chemicals and heat costs are reduced, labor costs increase because of increased work time. A slight increase in chemical and fuel costs actually reduces labor costs, because work time decreases. Work smarter- soap and heat are cheaper than labor. 
  • Washers with chemical injection before the pump, start out with the meeting valve open 1/4 turn. Then adjust as needed. 
  • W-200 Spray Wax is similar to spray wax used in coin-operated car washes. Apply the wax hot and follow with a cold rinse for fine surfaces like cars and pickups. On heavier surfaces, like home and trailers, the cold rinse is not necessary. The application of wax extends the life of the wash job, makes subsequent cleaning easier, and enhances the overall appearance. Note: Because the application of wax will extend the life of a wash job, some contractors choose not to use it because of the extended life of your cleaning, the enhanced appearance and extended life may generate more business because of the perceived quality of the work. 
  • For fleet washing, wax in the rinse water reduces dirt adhesion and lessens subsequent washing time. In heavy concentrations, wax reduces cement adhesions on concrete trucks.


The tips provided in this section will reduce brushing to about 5 percent of the the total workload. Typically, contractors only brush in the spring or the fall, or as needed. Brushing once or twice per year at a specified time allows the contractor to prepare and schedule extra, short-term, help for those designated times.


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