A pressure washer has a pump that takes water from a garden hose and boosts the pressure up to 1,000 PSI or more. The pressurized water coming out of the spray wand then dislodges the dirt and grime and that collected on house sidings, driveways, vehicles and gutters.
Power washers come in two types: electric and gas. Electric pumps can deliver in the range of 1,300-1,400 psi (pounds per square inch) at about 1 1/2 gpm(gallons per minute). Electric washers are more suitable for light cleaning work, such as cleaning outdoor grills, garage floors and washing cars. They should always be connected to power outlets that have an integrated ground fault circuit interrupter (GFCI).
Gas-powered washers operate in excess of 3,000 psi and can handle tougher cleaning tasks, like driveways, tile and grout cleaning, mildew covered decks and siding for houses.
While pressure washers are extremely effective at power washing, they cannot always do a completely thorough job. You will get the best results using the pressure washer in addition to hand tools. If you have severe mildew, it’s helpful to pre-treat the stained area with a solution of water and bleach. Do not ever put any type of bleach into a pressure washer because the strong chemicals can damage the washer’s parts.
Selecting a Nozzle: Using the correct nozzle is essential to getting the best results. Choose a nozzle with a wide spray, 40 degrees, for soft materials like wood. A very thin, concentrated stream is used for stubborn stains on hard surfaces, such as concrete.
Spraying: Using the correct spray pattern is important to getting good results. Start spraying from about four feet away and slowly move closer until you get effective cleaning. Maintain this optimum distance while cleaning. Do not get too close to the work surface because you have the risk of damaging the surface.
Start spraying at the top and work down. Overlap the spray pattern to prevent streaking. Point the spray at an angle to the work surface. Spraying directly into the surface can drive dirt and grime into the surface, rather than washing it away.
Be sure to always direct the water flow downward when spraying the siding of houses. Siding is designed to provide protection from water flowing downward, not water being sprayed upward from a pressure washer.
To get the best cleaning results, loosen the dirt first with high pressure and a medium spray pattern. Then, spray a detergent using a wide nozzle setting and let it set for a few minutes to get better penetration. Finish off the cleaning by rinsing with plain water and a medium spray pattern.
Protection: Always wear eye protection when doing a pressure washing job. If you are using strong or caustic chemicals, wear long sleeve shirts, pants and gloves to prevent the cleaning detergents from coming in contact with your skin.
Precautions: Pressure washers are very powerful tools and can cause damage to other property and people. Be careful when spraying around windows, outside lights and any delicate items that may be on a deck. A nozzle is like a gun, so never point it at anyone.