Put the pressure on—and get the grime off
If you’re looking for an easy way to quickly blast away all the mud and stains from your driveway, siding, and truck tires with one device, look no further than a pressure washer. Thanks to its ability to spray highly pressurized water (usually mixed with a cleaning solution) at the offending dirt or stain, a pressure washer can make your home’s exterior look brand new.
But before you start showering everything in sight, make sure you’re operating the pressure washer safely and knock out all those outside cleaning chores before lunchtime.
Before you can choose the right pressure washer for the job or learn how to use a pressure washer, there are several terms to familiarize yourself with. Knowing these terms can make the entire job easier by deepening your understanding of how your pressure washer works.
GPM: This refers to gallons per minute, or the amount of water moving through the pressure washer pump each minute.
PSI: The pounds per square inch measures the force of the water coming out of the pressure washer nozzle.
ECU: The total power of a pressure washer is measured in effective cleaning units, or ECUs, which is the GPM multiplied by PSI. ECUs can range from around 1,950 to 4,400 for light-duty models or up to 8,000 for medium-duty models.
High-pressure hose: This hose connects the trigger handle to the pressure washer and can withstand the high pressure of the water coming from the pressure washer.
Downstream injector: This part of the pressure washer adds your cleaning solution into the water before it flows out of the nozzle.
Unloader: The unloader can help reduce pressure buildup or change the PSI.
Turbo nozzle: A turbo nozzle, also called a rotary nozzle, is red and has a zero-degree spray angle that moves in a circle for powerful cleaning.
Broom: A pressure washing broom can split one stream of pressurized water into two or three to clean a wider area.
Soft wash: A soft wash is when you set the pressure washer to a low PSI and use a gentle nozzle plus a cleaning agent, like you would for cleaning before painting.
Pressure washers come in gas or electric models. When it comes to gas versus electric pressure washers, gas-powered washers deliver 2,000 to 2,800 PSI , and electric models put out 1,300 to 1,700. Because of this, gas washers are generally considered more powerful and can clean 10 times faster than electric models. That said, gas-powered washers are noisier and require more caution and care to not damage wood or other surfaces.
While you should pay attention to PSI when choosing a pressure washer, you should also check the washer’s water flow in gallons per minute. For instance, a machine with 5 GPM and 1,700 PSI will clean better than a machine with 4 GPM and 2,000 PSI. In addition, select a washer that will dispense cleaning solutions in addition to water. A little bit of chlorine can go a long way to clean concrete and prevent mold and mildew buildup.
Pressure washers are extremely powerful machines and can be dangerous if handled incorrectly. When operating a pressure washer, be sure to equip yourself with the following personal protective equipment (PPE):
Goggles
Face shield
Mask or respirator
Gloves
Work boots
Long sleeve, but not loose-sleeved, shirt
Ear protection
Waterproof suit or PVC rain pants
Before you turn the pressure washer on, make sure no one is around and potentially in the spray’s way. Additionally, grip the machine with two hands and be careful before you make any sudden movements.
Some of the biggest pressure washing mistakes are from not prepping the machine and the area before starting the job. Make sure you have an adequate water supply. Otherwise, your pressure washer won’t be living up to its potential. Clear any items and debris that might get in the way of your cleaning spree—things like toys can easily get damaged if accidentally hit.
"Before using a power washer, make sure to clear your space. Move any debris, cover electrical outlets, shut your windows, and drape your plants with tarps to protect them."
— John Gabrielli, Owner of Air Temp Solutions, New Castle, Delaware
Your rose garden might not look so rosy after it’s been hit with pressurized chlorine, so watch where you spray. Additionally, consider watering your plants before, during, and after you pressure wash, so any cleaning solution that hits them is diluted (dry leaves absorb cleaning solutions much easier than wet ones).
Absolutely do not try to save some time by using your pressure washer on your garden while you have it out. A pressure washer is not a hose and should never be directed toward any living thing. Keep these powerful tools away from plants, children, and pets.
Aside from protecting your gardens, protect any other vulnerable items in the area you’ll be pressure washing. Move outdoor furniture and decor away from the patio you’re going to clean, and cover windows and doors with a tarp. You should still avoid spraying the pressure washer toward these covered spaces, but the tarp can help protect against accidental sprays.
There are many different types of cleaning solutions you can use with a pressure washer. Understanding the different cleaners and what they can be used on and for is imperative for achieving great results with your pressure washer.
Vinegar: Safe and effective for most surfaces as a general cleaner
Citric acid: Ideal for concrete and wood
Oxalic acid: Excellent at removing rust
Sodium hydroxide: Can break down grease, oil, and other lipids
Potassium hydroxide: Used for mixing soft soaps
Ammonia: Commonly used for exterior glass
Bleach: Bleach should only be used to clean mold and mildew—it can corrode metal, kill plants, and remove color from clothing
When choosing a cleaning solution, don’t attempt to DIY your own concoction. Always follow product label instructions, and never mix bleach and vinegar because this creates poisonous chlorine gas.
No matter what surface you’re planning to wash—be it a brick wall, a concrete floor, or vinyl siding—do a survey of the area and note any cracks or holes in the surface. Repair these spots before you begin the washing process and give them the appropriate time to cure or dry, depending on the kind of repairs made.
Before you begin pressure washing, you’ll need the device to have the proper fuel or power supply. For electrical pressure washers with a cord, this is as easy as plugging the unit into an outdoor outlet. If you have an electric pressure washer with a battery, fully charge it before you start. For gas pressure washers, use a gas with less than 10% ethanol.
Hitting any surface with a high-pressure shock of water can be intense, so ease your way into the washing. Start by washing from 10 feet away, and move in a little closer to the surface until the pressure is just enough to loosen and remove any grime.
Taking your time will help ensure you end up with a quality result and that you stay safe while cleaning. If you rush, you could hurt yourself, damage your home, or just end up with a sub-par job that needs to be done again.
There’s a reason your pressure washer comes with various nozzle tips—they handle different jobs. A wide nozzle is excellent for wood decks or your home’s siding. A more narrow nozzle can tackle the grime on brick and concrete. A 15-degree nozzle or less will dispense extremely high pressure and should only be used to get rid of stains on metal. Nozzle tips are universally color-coded to help you select the right one.
| Nozzle Tip Color | Spray Angle | When to Use |
|---|---|---|
| Red | 0 degrees | Far distances; never use up close |
| Yellow | 15 degrees | Surface prep for painting, staining, and resealing |
| Green | 25 degrees | Cleaning masonry |
| White | 40 degrees | General pressure washing; home exteriors |
| Black | 65 degrees | Gentle rinsing |
You should always use the lowest degree you can get away with for the material and stain you’re cleaning. Apply cleaning solution from the ground up, and then rinse from the top down without letting the cleaning solution dry.
To get the most power out of your washer, keep the nozzle perpendicular to the surface you’re cleaning. If you need to clean a difficult-to-access spot, like high-up siding, consider investing in a nozzle wand that pivots.
"Never spray anything head-on because this can cause damage. Spraying at an angle allows for better control and helps you reach more surfaces without having to repeat the same movements over and over again."
— John Gabrielli, Owner of Air Temp Solutions, New Castle, Delaware
If you pause in the middle of cleaning a section of pavement, siding, or other surface, the finished look could be streaky. Instead, keep moving the pressure washer until you reach the end of the surface, then pause if needed. If you do pause for longer than a couple of minutes, squeeze the pressure washer trigger so that the water can help cool the pressure washer pump and prevent it from overheating.
Some stains—like those from acorns, fertilizer, oil, and rust—are forever, and there’s not a lot you can do about it with DIY pressure washing. In addition, some big or high-up jobs require more tools than you might have on hand. Rather than overdoing it and risking damage to your home (or yourself!), consider calling in a local power washer to assess the situation; the cost to pressure wash a home ranges from $100 to $650.
There are several materials you should avoid pressure washing to prevent damage:
Surfaces painted before 1978, when the U.S. government banned lead-based paints
Electrical fixtures, such as meters or lighting
Roof shingles
Gutter interiors
Air conditioners
Awnings or other shade coverings
Always test the area you plan to clean by pressure washing a small, hidden area on a lighter setting and from a distance. Call in the pros if you’re worried about whether your pressure washer will damage your siding or patio. The downsides of DIY pressure washing are that inexperience and confusion can lead to costly damage, so don’t hesitate to bring in an expert if you feel unsure.
Pressure washer maintenance is essential to keeping your machine up and running when you need it. Store your washer indoors during the off-season to prevent any weather-related damage. You can also winterize the machine by filling the pump with undiluted RV-grade antifreeze. After using the machine with any cleaning solution, be sure to run it a few times with just water to remove the cleaning solution—any chemicals left behind in the machine can damage the inner parts and shorten the lifespan of your pressure washer.
The amount of pressure, measured in psi, that you should use depends on what you’re washing. Very tough materials like concrete, stone, and masonry can handle a high psi of 2,500 to 3,000, but materials like wood require a bit of a lighter touch. To clean your wooden deck, you’ll want to use your pressure washer on the lowest setting, around 600 psi, especially if it’s made of soft wood like pine or cedar.
Yes, you can pressure wash vinyl siding. Because vinyl is a pretty durable material, it can withstand up to 3,000 psi. However, you’ll still need to be cautious and operate the pressure washer correctly to avoid costly damage to your home’s exterior. Remember to repair cracks or damage to your siding before you clean it with a pressure washer.
This answer is a bit tricky because experts say both. You should apply your cleaning solution from bottom to top, but rinse from top to bottom to avoid streaking. When it comes to multi-story houses, you’ll want to start at the top floor and work your way down, but follow the above instructions for each level as if it were an independent structure, rather than washing the whole house as one unit.
We don’t advise using dishwashing liquid in your pressure washer, as it is meant to be mixed with water that is cooler than what gets pushed through a pressure washer. The warmer water makes the dish soap very sudsy, which can damage your pressure washer’s tubing and other components.
