When using a pressure washer, it’s important to consider the amount of pressure before you even turn on the machine.
Pressure is measured in pounds per square inch, or PSI. The PSI requirement usually changes depending on different tasks and what needs to be cleaned. For example, the PSI value for cleaning stubborn stains on your floor or patio would be higher than the PSI required for cleaning your car.
So how do you choose the right PSI for your pressure washer?
This depends on the strength of the chemical bond between the stain and the surface. The stronger the bond, the more water pressure is required to remove it.
If you need help choosing the right PSI for your pressure washer, then you’ve come to the right place. We’ve got all the information you need to know right here, including a chart that shows what kind of water pressure is required for certain tasks.
Knowing the required PSI to complete different tasks, will help you to choose a pressure washer that’s powerful enough to clean what you need and gentle enough not to damage the surfaces.
PSI and Cleaning Tasks
As we’ve said, the power of the machine you choose should depend on the tasks you will be using the machine for. This will also impact the type of pressure washer you choose – gas or electric.
In general, electric pressure washers have lower power and are ideal for residential purposes. Gas pressure washers are more powerful and can be used for both residential and industrial purposes.
| Required PSI | Task |
| 1000-1900 | For home cleaning and vehicle cleaning tasks For use with handheld electric model |
| 2000 – 2900 | For more difficult, heavier residential cleaning tasks For use with electric or gas models |
| 3000 – 6900 | For professional use. Eg. Commercial/industrial tasks For use with gas models |
| 7000 – 50,000 | For engineering and industrial jobs which involve bigger equipment and structures. Eg. Bridges and large buildings |
Choosing the right PSI for your pressure washer can be difficult since there are many ways a pressure washer can be used. Most pressure washers will have adjustable nozzles and pressure gauges, which allow you to choose the right force for the job.
To clarify all this, here’s a chart that will give you an idea of the PSI you’ll need for some of the most common cleaning projects with pressure washers.
| Application | Light Duty 1500-1900 PSI | Medium Duty 2000-2800 PSI | Heavy Duty 2900-3200 | Extra Heavy Duty 3300 PSI and higher | MultiDuty 500-3000 PSI Gas + Electric |
| Fences | X | X | X | X | |
| Cars/Trucks | X | X | |||
| Sidewalks | X | X | X | X | X |
| Patio Furniture | X | X | |||
| Industrial Equipment | X | ||||
| Stairs | X | X | X | X | X |
| Garage Floors | X | X | X | X | |
| Driveways | X | X | X | X | |
| Power Soaping | X | ||||
| Paint Prep | X | X | |||
| Siding | X | X | X | ||
| Stain Removal | X | X | X | ||
| Boats & ATVs | X | ||||
| BBQ Grills | X | X | X | X | X |
| Docks & Decks | X | X | X | X |
What’s the Required Water Flow?
Although water pressure gives you the power to break up dirt and stains, it’s actually the volume of the water that flushes away all the filth which is broken up. The more water moves through the nozzle of your pressure washer, the faster and easier cleaning becomes.
Pressure washers combine very high pressure with a high water volume to clean all surfaces quickly and without much effort. This means that you should take the GPM (Gallons Per Minute) into account as well, since it plays a role in the cleaning that’s as equally important as the pressure.
However, there’s a trade-off to consider here. More water means higher utility bills and ongoing costs in the long run, whereas a low water flow rate means more water conserved. Extra heavy-duty pressure washers, with a PSI over 3200+, typically have a GPM of around 4 while light duty models may be as low as 1.5. Note that the GPM is just as important as PSI when choosing a pressure washer.
Again, the tasks you’re planning to use the pressure washer for will largely dictate which type to buy.
The Bottom Line
Buying a pressure washer is a significant investment, which is why choosing the correct machine is important. A pressure washer with the wrong pressure is a waste of money and time.
And finally, just because a pressure washer has more power doesn’t mean it’s necessarily better. If you’re not going to use a lot of power, there’s no point in paying for a machine that’s too powerful for the jobs you need it for.
The best pressure washer is the one with the PSI and GPM that’s right for the jobs you require it for.
If you’re looking to purchase a pressure washer, check out our detailed guide on how to buy a pressure washer.
