Match the ability to loosen dirt, measured in pounds per square inch (psi), to the type of cleaning projects you are using the pressure washer for.[1] X Research source A light-duty pressure washer with 1,200 to 1,900 psi can clean 10 to 40 square feet in 10 minutes. This would be a good model for cleaning a vehicle, garage floor or patio furniture. A medium-duty pressure washer with 1,950 to 2,600 psi can clean 40 to 90 square feet in 10 minutes. This type of pressure washer can handle larger areas, such as a driveway, sidewalk or deck. A heavy-duty pressure washer with 2,650 to 3,800 psi can clean 90 to 190 square feet in 10 minutes. You'll need this is the type of pressure washer for cleaning a fence or siding, especially on a second story. Take into account the gallons of water per minute (GPM) that the pressure washer uses. Multiply this number by the psi to determine the true cleaning power of a particular pressure washer. Compare the benefits and disadvantages of gas versus electric pressure washers.[2] X Research source Gas pressure washers are more powerful, but they have drawbacks. They are loud; have the added cost of buying gas, oil and spark plugs; are more difficult

to start and have polluting emissions. Electric pressure washers are tethered to an electrical extension cord, which can restrict movements. The unit's power cord should have a built-in ground fault circuit interrupter (GFCl) to prevent electrical shock. Their electric motors are the limiting factor on their lifespan, as they are more prone to overheating and shorting out. Electric washers, however, tend to be far lighter than gas models (electric power washers start at a mere 15 lbs, where gas washers can weigh up to 200 lbs. [3] X Research source Evaluate the spray nozzle.[4] X Research source A telescoping wand helps to clean second-story siding and other raised areas (operating a pressure washer from a ladder isn't recommended). The width of the spray, which may range from a concentrated jet to a 40-degree fan, may be adjustable by twisting the nozzle or attaching different tips. Typically, most residential pressure washers include 4 interchangeable tips: 0°, 15°, 25° and 40°. If you're unsure of which nozzle tip to use, be sure to test on an inconspicuous area of the same material by starting from 3–4 feet (0.91–1.2 m) away and moving closer. Look at the accessories,

such as a broom attachment for pavement or an attachment for cleaning gutters. Rotating "surface cleaner" attachments work well for large, flat areas like driveways and sidewalks, and tend to leave a more uniform clean than using just the nozzle (i.e. less "streaking").[5] X Research source Consider the weight of the spray gun and extension wand. A heavier hand unit will require 2 hands to operate. Decide whether you want the ability to use a cleaning detergent for extra cleaning power on heavy stains, mold and mildew. This requires a pressure washer with a cleaning solution injection system. You may find a pressure washer with a cleaning solution storage tank easier to use than simply pumping the solution out of a nearby bucket. Look at the job you'll be doing and think it out in advance, you may need to purchase a longer hose to the machine or from the machine to the area you'll be cleaning. Petrol powered washers may use more water than a hose can deliver, a simple solution to this is a small tank like a wheelie bin adding a water tank ball cock means it'll top up when needed. Recognize whether you need to winterize your pressure washer. If you live in a cold area, you'll need

to drain all of the water out by running the motor briefly with no water supply. Turn the machine off and continue to hold the handle. To preserve seals and rubber parts, consider using "Pump Saver" anti-freeze for gas models.[6] X Research source