Buying Guide: Commercial Pressure Washers

by Lawton Brothers | Aug 22, 2023

There are countless projects that can make use of a pressure washer and they are very versatile pieces of equipment to own. However, no matter the task at hand, it’s essential to choose the correct washer for the job. Each type serves a different purpose, so how can you compare and decide on the right unit? With this curated guide, of course. 

Choosing the Right Pressure Washer

The first step when selecting a pressure washer is understanding the key terms and what they mean, so you can compare them.


  • Pounds per square inch: water pressure is measured in pounds of pressure per square inch (noted PSI). The PSI rating is used to illustrate how much pressure is needed to remove a particular stain. The stronger the chemical bond, the more pressure needed to remove it.



  • Gallons per minute: water flow is measured in gallons per minute (GPM). The higher the GPM, the more surface area a pressure washer can clean in a minute. If one washer has a GPM rating of 2, and another has a GPM of 4, the latter pressure washer (with 4GPM) will clean an area twice as fast.



  • Cleaning units: also referred to as cleaning speed, is the combination of the PSI and GPM. By multiplying these two numbers, you will get a measurement for the cleaning units (CU). This gives a better overall view of the product as opposed to looking at just the PSI or GPM, alone.



  • Water temperature: when it comes to the higher level, professional units, you will have an option for the water temperature. Using unheated water is standard across all pressure washers, but only some professional units are capable of handling hot water.



  • Cold water pressure washers are great for most general-purpose jobs, like facility maintenance, automotive work, and more. Hot water pressure washers are for the toughest jobs, to lift mud, grime, and stubborn stains.


Before buying a pressure washer, always check the PSI, GPM, and CU. Selecting the correct PSI is essential based on the task is essential, since a higher force could damage some surfaces. PSI is divided into 4 categories – light duty (0-1999 PSI), medium duty (2000-2799 PSI), heavy-duty (2800-3299 PSI), and industrial duty (3300+ PSI). 

Electric vs Gas

There are many people who make use of electric pressure washers, as they are simple to use, lighter, smaller, and quieter than their gas-powered counterparts. However, electric pressure washers tend to have a lower life expectancy, with most lasting only a few hundred work hours. For smaller jobs and less frequent usage, an electric pressure washer can still be a good option, especially since they tend to be cheaper than gas-powered ones. But keep in mind the length of the cord and access to electricity near your projects. 

There are many more people who opt for a gas-powered pressure washer. These units are much more powerful, last much longer, and have the ability to be repaired. Almost anything on the metal frame can be repaired or replaced without replacing the whole unit. Additionally, since it uses gasoline, the pressure washer can go anywhere the job is. Most professional models are gas-powered and can be customized. 

Selecting a Nozzle

  • Pressure washers generally come with an assortment of interchangeable nozzles (sometimes color-coded) or a single all-in-one, adjustable nozzle. This will allow you to change the angle of the water spray to best suit your project.


  • Zero degree – often colored red, this nozzle creates high concentrated pressure to clean areas. It is mainly used for heavy-duty jobs like clearing heavy buildup on concrete or removing rust from equipment.



  • 15 degree – usually yellow, this nozzle is used for intense-moderate to heavy-duty cleanings, like stripping paint from wood, metal or masonry, or removing oil, grease, and mildew stains.



  • 25 degree – this attachment is used for tackling general, light-duty tasks like washing decks and outdoor furniture. This nozzle is typically green.



  • 40 degree – the white 40-degree nozzle is often used for light-duty tasks on surfaces that can be more easily damaged, like windows and cars.



  • 65 degree – the widest and gentlest spray pattern belongs to the black 65-degree nozzle. Often used for applying detergents or rinsing soap.


Using the wrong nozzle or tip for your pressure washer could result in costly property damage and even injury. Concrete damage as well as broken window seals and damaged wood are all commonly caused by improper tip use. To help reduce the risk of damage or injury, avoid using the zero-degree setting on your unit. The higher-degree settings can get most jobs done, without putting you at risk. 

After selecting the appropriate nozzle, make sure your pressure washer is properly connected to a water supply before turning it on. Never keep your pressure washer running on idle for more than a few minutes, as this can damage the pump and internal control valves. If you won’t be spraying, it’s best to simply turn off the machine. 

The Pressure is Off

Lawton Brothers is here to help with all your janitorial needs. We hope this guide made understanding pressure washers a breeze. But if you still have questions, we’re here. With a team of certified experts, we’re happy to help guide you in the right direction. Give us a call today at: 800.432.0813

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