One of the questions we get asked is how much psi do I need? Customers are concerned with using too much pressure or maybe they have damaged their property in the past. Currently Portland Pressure Washing uses about 2800 PSI or pounds per square inch. What actually more important is the gallons per minute, not the (psi) pounds per square inch. Water volume is a much better cleaning agent than the amount of pressure used. Our current residential setup is a Landa Northwest 6/3200 which means 6 gallons per minute at 3200psi. With hose extensions and the fittings we get around 2800 psi at the tip. If Portland pressure washing is working a flat surface that figure is split in two because of the surface cleaner to 1400psi at 3 gallons per minute. A surface cleaner is used to clean an area evenly with the maximum amount of consistency and efficiency to provide the best results.
Often we show up at a jobsite and see small swirl marks on the driveway about as wide as a finger in various places with a trail of missing aggregate. Or that new $30,000.00 cedar deck that was just installed last year chewed up with deep gouges all over the place. This is a good indication that the homeowner realizes that the pressure washer purchased at the local big box store is not quite up to the task of those large jobs. We want to educate the consumer with pressure washing information so they can save money, not ruin their property. We do run into the occasional customer who has us back year after year after spending 3 weekends to clean their driveway just to prove they could do it!
Commercial grade pressure washers range from 4 to 10 gallons per minute and can cost between $1500 to $20,000 depending on a number of variables such as hot water, mounting options and quality of components. Commercial grade pressure washers are made to run day after day providing years of service with good maintenance. For cleaning large flat areas surface cleaners are used to provide the best quality cleaning with the most consistent results. Surface cleaners range in price from $500 – $2000 and can improve the clean up speed while providing superior results. Surface cleaners also eliminate the “tiger stripes” that often appear on driveways after a driveway is pressure washed by hand. This is caused because of the inconsistent swing of the operator while controlling the pressure washing wand.