Before using a pressure washer
If you’ve never used a pressure washer, take a minute to learn the basics and prepare for your job. We’ll explain key parts and accessories, including choosing the right nozzle, plus advice on how to use a pressure washer safely.
How pressure washers work
Pressure washers aren’t complicated. An engine (gas) or motor (electric) powers a water pump. Water is drawn into the pump from a source, like a garden hose, where it is accelerated to high pressure. The pressurized water is released from the pump by pulling the trigger on a spray gun, which is connected using a high pressure hose. At the end of the spray gun, wands and nozzles are connected to control the stream of pressurized water.
How to choose a nozzle
Nozzles control the water’s spray pattern. Some are fixed, meaning they only produce one pattern, while others are adjustable to produce multiple patterns. Regardless of the nozzle type, there are six common patterns. Use the nozzle chart and descriptions below to compare use cases for each pattern.
- 0° nozzle (red). Produces a straight jet with maximum pressure for spot cleaning deep stains.
- 15° nozzle (yellow). Produces a flat fan with high pressure for stain removal and paint prep.
- 25° nozzle (green). Produces a flat fan with medium pressure for general cleaning.
- 40° nozzle (white). Produces a flat fan with light pressure for rinsing.
- 65° nozzle (black). Produces a wide mist with minimum pressure for applying detergent.
- Turbo nozzle (no color code). Rotates a straight jet to produce a hollow cone with maximum pressure for more efficient stain removal.
Risks and safety tips
Pressure washers can be dangerous to both you and your surroundings. Taking the following precautions can reduce the risk of injury, damage and other consequences.
- Prepare your operating area. Remove or cover any objects that are blocking the surface or could be damaged by water or high pressure. Examples include furniture, plants, lights and outlets. Consider sealing doors and windows with tape.
- Wear protective clothing. Highly pressurized water will send debris flying everywhere, not to mention direct contact would break skin immediately. Never spray yourself or any other human or animal, and always wear safety glasses, enclosed shoes, gloves and full-length clothing. Consider wearing ear protection when using a gas pressure washer.
- Work on stable surfaces. Surfaces are slippery when wet and the spray gun will have some kickback when you’re pulling the trigger, so use both hands and keep your feet on the ground. Avoid ladders and other unbalanced areas that could result in a painful fall.
How to start a pressure washer
Gas and electric pressure washers are started differently. However, before starting the engine or powering the motor, some initial setup is required. The following steps can be used to set up both types of pressure washers.
- Set your pressure washer on a flat, stable surface.
- Check the filter on the water inlet to make sure it’s clean and secure.
- Connect your garden hose to the water inlet (don’t turn on your water supply yet).
- Connect the male end of the high pressure hose to the water outlet.
- Connect the female end of the high pressure hose to the bottom of the spray gun.
- Select a nozzle and connect it to the tip of the spray gun or wand, if you have one.
- Turn on your water supply.
- Pull the trigger on the spray gun and hold for 30-60 seconds to purge air bubbles.
With accessories connected and the pump primed, your pressure washer is ready to be started. Starting an electric pressure washer takes only two steps: plug the power cord into an electrical outlet and switch the power to ON. Instructions for starting a gas pressure washer are below.
- Open the fuel valve.
- Open the choke.
- Open the throttle.
- Switch the engine to ON.
- Pull the trigger on the spray gun and hold while completing step #6.
- Pull the recoil starter or press the electric start button, if you have one.
- Allow the engine to warm up for 15-30 seconds, then close the choke.
How to use a pressure washer
Learning formal pressure washing practices will make your jobs faster and easier while reducing the risk of damage. We’ll start by discussing general techniques, then we’ll provide specific instructions for some of the most common surfaces.
- Test the pressure. Pick a small, unnoticeable area to clean first. Start with the nozzle around two feet away from the surface and check the results after a few seconds of spraying. If the surface isn’t cleaned to your standards, repeat this test while moving the nozzle closer to the surface, but no closer than 6” to avoid damage. If you need to get this close for good results, consider a narrower nozzle that you can spray at a safer distance.
- Use long, overlapping strokes. Move the nozzle in a sweeping motion from side to side, using long strokes around 3-4 feet wide. Each time you switch directions, overlap your previous stroke to get an even finish. Tougher surfaces may require a few passes over the same area.
- Clean top to bottom. Consider which direction water will run while you’re spraying. Starting with the highest area and working your way down will prevent streaks and make rinsing easier since you’re working with gravity.
- Keep moving. Unless you need to do some serious spot treatment, try not to hold the stream in one place for too long. Constant pressure to a single area can cut into certain surfaces, especially if you’re using a narrow nozzle.
How to pressure wash cars (paint, engine, etc.)
Pressure washing cars takes under an hour. Low pressure is recommended, so use a 40° nozzle and spray at a distance of 2-3 feet from the surface. Rinse the exterior first, then apply soap. Most car wash soaps aren’t pressure washer safe, so use an accessory like a foam cannon for soap application. Use microfiber towels or a soft brush to wipe the soapy exterior, then rinse and towel dry. Be mindful of windows, mirrors, badges and other exterior parts that could be damaged by pressure.
How to pressure wash siding (vinyl, stucco, etc.)
Pressure washing siding takes 2-4 hours. Medium pressure is recommended, so use a 25° or 40° nozzle and spray at a distance of 2-3 feet from the surface. Apply detergent first using the soap nozzle, then rinse. Use a telescoping wand to reach second stories or high walls and a foam brush to loosen tough grime. Keep your nozzle angled down to avoid getting water behind lap siding. Be mindful of windows, lights, outlets and other exterior fixtures that could be damaged by either water or pressure.
How to pressure wash concrete (driveway, garage, etc.)
Pressure washing concrete takes 1-2 hours. High pressure is recommended, so use a 15° or 25° nozzle and spray at a distance of 1-2 feet from the surface. Sweep the surface with a broom to remove loose debris before you begin. Apply detergent using the soap nozzle, then rinse. Use a surface cleaner to cover larger areas in shorter time and degreaser to remove tough stains. Be mindful of grass, gardens and other greenery that could be polluted by chemical runoff.
How to pressure wash wood (deck, fence, etc.)
Pressure washing wood takes 1-2 hours. Medium pressure is recommended, so use a 25° or 40° nozzle and spray at a distance of 1-2 feet from the surface. Scrub the surface with a stiff brush to remove old stain before you begin. Apply detergent using the soap nozzle, then rinse. Use a foam brush to loosen tough grime. Allow the surface to air dry for 24-48 hours before applying finish. Be mindful of grass, gardens and other greenery that could be polluted by chemical runoff.
How to pressure wash brick (patio, chimney, etc.)
Pressure washing brick takes 1-2 hours. Medium pressure is recommended, so use a 25° or 40° nozzle and spray at a distance of 1-2 feet from the surface. Patch any cracks or holes at least a week in advance. Soak the surface with water first, then apply detergent using the soap nozzle. Rinse thoroughly as brick is very absorbent. Allow the surface to air dry for 48-72 hours, then use a stiff brush to remove any exuded residue. Be mindful of grass, gardens and other greenery that could be polluted by chemical runoff.
How to shut down a pressure washer
When you’re done using your pressure washer, shutdown is simple. With an electric pressure washer, switch the power to OFF and unplug the power cord. With a gas pressure washer, switch the engine to OFF and close the fuel valve and throttle. Continue with the following steps for storage.
- Turn off your water supply.
- Pull the trigger on the spray gun and hold until all remaining water is released.
- Disconnect the garden hose from the water inlet.
- Disconnect the high pressure hose from the water outlet.
- Disconnect the high pressure hose from the spray gun.
- Disconnect the nozzle from the spray gun or wand, if you have one.
- Towel dry all accessories, especially their fittings.
If you don’t plan to use your pressure washer again in the next 30 days, some extra steps are required. Spray pump saver into the water inlet and add fuel stabilizer to the fuel tank for protection against moisture and corrosion. Keep in mind, fuel stabilizer should be added before turning the engine off and circulated for at least two minutes.
Frequently asked questions about using a pressure washer
Some of the most common questions about using a pressure washer are answered here. If you need additional help, you can reach out to us at any time. For questions about specific products, we’re happy to offer advice, but depending on the question, you may receive better information contacting the manufacturer.
Do you need to use detergent?
Detergent is very helpful when you’re dealing with tougher jobs because it loosens particles from the surface, but generally, you can get great results without using detergent. With that said, detergent may be necessary in some heavy-duty cases, like cleaning hazardous materials.
What kind of soap can you use in a pressure washer?
Certain chemicals can damage parts of your pressure washer and be dangerous to you and your surroundings. For safety, only use cleaning products that explicitly state their approval for pressure washer use. Avoid the commonly questioned products below.
- Bleach is highly effective at removing stains, mold and mildew, but it will corrode seals and pose a serious threat to humans and animals as an airborne mist.
- Dish soap is cheap and easy, and although it’s not corrosive, its residue will build up inside your accessories and on any surface you clean.