Last Updated On April 25th, 2016
Pressure washers are recommended for cleaning jobs that are too heavy for a hose or a mop. Pressure washing is not ideal for all surfaces (it can damage brick, stucco, or some types of siding). However, it works well on wood and some wood-type siding such as Hardiplank, on concrete, on grills, and on car exteriors.
If you’ve decided to purchase or rent a pressure washer to make cleaning easier, here are instructions on how to use it for the first time:
1. Choose a pressure washer to rent or purchase.
Pressure washers use either electric or gas-powered pumps to add over 1,000 pounds of pressure to the water from a garden hose. More pounds of pressure per square inch (psi) means a stronger wash job and, naturally, requires a steady flow of more gallons of water per minute (gpm). Electric pressure washers typically require 1.5 gpm and deliver 1,300-1,400 psi–enough to wash cars. Gas pressure washers require 2-3 gpm and may deliver up to 3,000 or even more psi; they’re recommended for washing houses and driveways.
2. Check the manufacturer’s manual (and ask the dealer) for specific instructions.
Following are general tips for using most types of pressure washers.
3. Check your hose.
Most pressure washers attach to a 3/4″ hose. Make sure it delivers enough gpm (this can be checked by timing how fast the hose fills a 5-gallon bucket). Remove any kinks or obstructions from the hose or the water inlet on the pressure washer. RealSimple.com advises, “You will get wet, so dress to enjoy it.” Water and dirt will splash back at high pressure, so wear safety glasses. Also, make sure all house and car windows are shut, and avoid squirting overhead power lines.
4. Do you need detergent or other supplies?
Pressure alone will remove most types of dirt. Mold spores, however, may activate and spread when wet. To kill mold spores, use a washer with a detergent tank and follow the instructions for mixing bleach and suitable detergent (Jomax “mildewcide” is recommended), or pre-wash with this mixture. Other useful accessories include tarps, rags, brushes, and extension handles for brushes.
5. Should you work from a ladder?
Family Handyman says, basically, don’t use a pressure washer while on a ladder. Popular Mechanics says, basically, make sure the ladder and your position on it are secure. We’ll say, get to know the machine you’re using on the ground.
6. Start the washer.
Make sure hose connections are airtight. Set the spray wand to its lowest pressure setting. If you’re using a gas washer with separate nozzles, remove the nozzles. Turn on the water and squeeze the spray wand trigger to pump out air in the line. Start the washer and let it warm up for one or two minutes, with the trigger locked off, while adjusting spray settings or inserting nozzle tips. Avoid running the machine with the trigger off for more than three minutes.
7. Wet the surface with plain water at low pressure.
Individual machines indicate how to set the lowest pressure. Hold the nozzle at the recommended distance, preferably at a 45-degree angle to the surface. Keep it moving, and avoid blasting into corners, under edges, against windows, or into vents. Work from top to bottom. Wash the entire pressure-washable surface to avoid a patchy effect.
8. Loosen dirt with the medium spray setting and higher pressure.
When washing wood, work with the grain of the wood. Use the maximum pressure settings only if necessary.
9. If using detergent, apply it at this stage.
If the pressure washer doesn’t have a tank for detergent and bleach solutions, use a separate container to mix and apply them. Let detergent solution soak in for a few minutes but keep the surface wet.
10. Rinse with plain water, again at a wide spray setting and low pressure.
11. Turn off the machine, wipe down windows, and rinse plants that may have been exposed to bleach with plain water.
Although you don’t pressure-wash windows, they will be splashed, so wash them while they’re wet to prevent spots or streaks.
12. Before uncoupling the hose, turn off the water and squeeze the trigger to remove water from the system.
Drain the gas from a gas-powered washer, and add antifreeze if storing the machine in a cold garage for the winter.