How to Use a Pressure Washer

Wash siding, concrete floors, decks and even your car faster and easier.

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Gas or electric pressure washers will clean almost anything outdoors, and they work so quickly and dramatically that they're actually fun. Learn how to use one safely and efficiently.

Tools Required

  • Rags
  • Safety glasses

Materials Required

  • Special detergent for pressure washers

Pressure washers are a useful tool for any DIYer. Whether you’re washing the car or blasting years of accumulated dirt off the side of your house, you’ll see dramatic and quick results. They’re also fun to use, so much so that you may find yourself begging to clean your neighbors’ siding, driveways and cars once you’ve finished your own. You can even use a pressure washer to carve a pumpkin.

You can rent or buy a pressure washer to clean nearly any outdoor item. By following the pressure washer tips in this article, you’ll learn how to use pressure washers safely and efficiently.

How Does a Pressure Washer Work?

Pressure washers, whether they’re powered by electric motors or gas engines, run a pump that pressurizes the water from your garden hose to 1,000 lbs. or more, then forces it out through a spray wand. The higher the pressure (measured in pounds per square inch—psi), the tougher the cleaning jobs they can tackle.

Both types require a steady, uninterrupted supply of water (in gallons per minute—gpm). For occasional use, most homeowners will find that a washer with a pressure range of 1,300 to 2,400 psi works best. Here are a few tips for pressure washer maintenance.

What Kind of Pressure Washers Should You Use?

Electric Pressure Washers

Electric pressure washers deliver 1,300 to 1,400 psi, require about 1-1/2 gpm and are the best choice for light-duty cleaning like washing cars (Photo 3), outdoor grills and garage floors. They generally cost less and are quieter, lighter in weight and more portable than gas-powered washers. Many have built-in tanks for optional detergent use. Looking for more options? Get to know the benefits of a hot pressure washer.

Always connect electric washers to power outlets that are protected by a ground fault circuit interrupter (GFCI) and use only 12- or 14-gauge extension cords.

Gas Pressure Washers

Most pressure washers that you’ll find for rent or sale are gas-powered. This type can deliver higher water pressure than the electric kind, some more than 3,000 psi. But gas-powered washers also require more water: 2 to 3 gpm.

These washers are the best choice for bigger jobs like preparing siding for painting, removing “aging” stains from wood decks and deep-cleaning concrete. You can rent one at most home centers or tool rental stores, along with attachments and accessories like chemical injectors or longer spray wands for reaching high places. Learn why your gas-powered pressure washer won’t start.

The cost of a gas-powered washer (non-commercial units) can range from a few hundred to more than a thousand dollars, depending on the pressure they deliver, their features and the engine and pump quality.

Project step-by-step (7)

Step 1

Hook Up the Pressure Washer

It’s worth taking a moment to make sure your water supply can deliver the gallons per minute specified for your machine.

If your not sure whether or not your source can supply enough pressure, it’s easy to test. Time how long it takes your hose to fill a 5-gallon bucket. If it takes two minutes or less, you’ll be fine, since most pressure washers need 2-1/2 gallon per minute to work.

To ensure that water circulates unobstructed through the system, check the water inlet filter or screen and clean it of debris. Also, make sure the garden and pressure hoses are kink free.

Next, you’re ready to start connecting everything, starting with the high-pressure hose.

  1. Connect the high-pressure hose to the wand, or whatever attachment you’re going to be using.
  2. Connect the other end of the high-pressure hose to the machine.

Next, you’re going to need water to use the pressure washer, so connect your garden hose to the input valve. Both gas and electric pressure washers should have a standard connection for a garden hose.

  1. Screw the hose onto the connection point.
  2. Make sure all the connections are secure and tight.
  3. Turn on the water.
  4. Once the water is on, make sure there’s no water leaking from where the hose connects to the pressure washer.

If you’re using an electric pressure washer, the next step is to plug it into the outlet.

Pressure Washer Hookup

Step 2

Add Detergent to the Pressure Washer

Though they’re not always needed, detergents can increase cleaning effectiveness while reducing cleaning time. When renting or buying a pressure washer, inquire what accessories and detergents are available for it. To prevent damage to the internal parts, never run bleach in the machine or use detergents not designated for use in pressure washers.

Detergents can only be run through pressure washers using a wide spray pattern. In addition, electric power washers require a low-pressure setting on the spray wand. Follow your machine’s instructions for using detergents, diluting the detergent and (if necessary) hooking up a chemical injector.

When using detergents, keep surfaces wet to avoid possible discoloration or damage. Finish by resetting the nozzle to a medium pattern (or changing the nozzle) and rinsing with plain water.

Switch detergents by draining the first detergent from the pressure washer, rinsing the system with plain water and introducing the next detergent.

Step 3

Select the Nozzle for the Pressure Washer

Most pressure washers come with a selection of different nozzles that allow you to customize the angle of the spray for different jobs. The nozzles should be color coded, following a standard range of options across brands.

A 0-degree spray nozzle concentrates the water into a small, powerful stream. The larger the angle, the wider the spray from the pressure washer, which comes with decreased power.

The nozzle you choose will depend on what you’re using the pressure washer for. Wider patterns are good for spraying soap or detergent. Medium angles are used for general cleaning, and the narrow angles are for blasting deep stains.

  • Red: 0-degree spray
  • Yellow: 15-degree spray
  • Green: 25-degree spray
  • White: 40-degree spray
  • Black: 65-degree spray

Some pressure washers, usually the smaller ones, come with a single adjustable spray nozzle that delivers zero to 60-degree fan patterns. Some brands offer accessory “rotating” or “turbo” nozzles that clean more effectively than standard adjustable nozzles because they spin the water stream.

Insert individual nozzle tips into the spray wand by retracting the quick-coupling collar, pushing the tip in as far as it will go and releasing the collar. Pull on the tip to confirm that it’s firmly locked in position. Point the spray wand away from people and property when starting the power washer.

Pressure Washer Nozzlesvia

Step 4

How to Start a Pressure Washer

Electric pressure washers usually start with a simple push button feature. Once everything is hooked up properly, just flip the switch, and you’ll be ready to go.

To start a gas-powered washer:

  1. Clean any debris from the inlet filter.
  2. Connect any accessories.
  3. Run water through the washer for one minute to prime the system and remove any air.
  4. Squeeze the spray wand trigger to bleed water pressure.
  5. Pull the starter cord to start the engine.

For the best cleaning results without damaging any surfaces, first, test the pressure setting and spray pattern on an inconspicuous place. Get to know the unusual uses of pressure washers.

Starting A Pressure Washer

Step 5

Power Washing Tips and Techniques

Cleaning Siding

If you’re washing the siding on your house, start with the nozzle four feet from the house and move it closer, slowly, until you achieve the desired cleaning effect. Grip the wand with two hands, and direct the water stream at a 45-degree angle, moving the stream constantly. Don’t hold the spray wand head on to the siding. This drives dirt into the surface rather than washing it away.

Lay tarps around the house perimeter to protect plants and collect paint chips blown off during washing. Houses built before 1977 may have lead paint chips that will have to be collected and properly disposed of at a hazardous waste facility.

Work small areas at a time. To prevent streaks, start washing from the bottom and work up. For even cleaning, use long, overlapping strokes. Rinse the siding by working from the top down.

Avoid driving water up behind the siding by keeping the spray stream level. Use an extension spray wand for reaching higher places. Be careful when using a lance extension. The “kickback” can throw it into contact with power lines.

Don’t spray windows. The high pressure can break them.

Washing Cars 

Clean cars and other items with an accessory brush and detergent. First rinse the area with water, then switch to a detergent wash and finish with a rinse.

Cleaning a Driveway or Concrete Surfaces

Scour oil and dirt off a garage floor with a detergent:

  1. Rinse surface dirt off the floor at high pressure.
  2. Change the nozzle setting to low pressure to dispense detergent.
  3. Finish by changing the nozzle back to high pressure and rinsing with water.

Washing a Deck

Renew deck boards by holding the spray wand at a 45-degree angle 1 to 2 ft. from the decking. Keep the water stream constantly moving. Use a higher-pressure (2,000 psi or greater) gas-powered washer and a concentrated spray nozzle setting (15-degree).

cleaning wooden terrace planks with high pressure washerronstik/Getty Images

Step 6

Pressure Washer Safety

Pressure washers deliver extreme pressure and can cause serious injuries if misused. For safety, follow these guidelines:

  • Don’t point the pressure washer at people or pets or put your hand in front of the nozzle. The pressurized water stream could actually penetrate your skin or cause serious cuts.
  • Wear safety glasses when operating the washer.
  • Don’t use pressure washers while working from ladders. Once you squeeze the trigger, the powerful recoil on the spray wand can throw you off balance and off the ladder. Before you move ahead, get to know about different types of pressure washer oil.
  • Maintain a minimum 6-ft. distance when spraying water around power lines, electrical masts or outlets.
  • Before uncoupling hoses, stop the machine, turn the water faucet off and squeeze the spray wand trigger to release all water pressure in the system.
  • Engage the safety lock on the trigger when you’re not actually washing and when changing nozzle tips.
  • Wear eye protection and other personal safety gear.
Step 7

How to Winterize a Pressure Washer

Winterize a pressure washer by filling the pump and internal system with undiluted RV-type antifreeze. Insert a funnel into a 3-ft. section of garden hose (one with a male faucet coupling), attach the coupling to the water intake on the washer and slide a 1-ft. section of hose over the water outlet. Start the gas engine and pour antifreeze into the funnel until a steady stream of antifreeze flows from the discharge hose. Stop the engine, pull off the hoses, and seal the intake and outlet with duct tape.

If possible, store the power washer indoors in the off-season to avoid damage to the pump, hoses and spray wand. When a gas-powered washer won’t be used for a month or more, prevent damage to the engine by draining the system of gas or adding a gas preservative to the fuel tank.

Winterize Pressure WasherRobert Maxwell for Family Handyman