Choosing The Right PSI for a pressure washer

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When you’ve decided to buy a pressure washer, the next question is usually, what is the right psi for a pressure washer? How much do I need? Instinctively, in these situations, I usually go with the most powerful tool I can buy. Sure, I won’t need everything the tool has to offer right now, but I’ll undoubtedly make use of it as time goes on.

This isn’t the same with pressure washers.

Water pressures are measured using a system called pounds per square inch or PSI. The amount of PSI you’ll need will depend on the surface and the dirt you are trying to remove. Depending on how strong the chemical bond between the surface and the stain is, this will dictate how strong the PSI. The stronger bonds demand more water pressure to remove the stain.

When it comes to water flow rate, this is measured as gallons per minute or GPM. This is an important number because it’s not how much water flow the pressure washer can produce. It’s also a limiting factor for you. Can you supply the pressure washer with the GPM it needs? I’ll show you how to calculate this later.

On top of the stains or dirt you are trying to remove, the surface will also dictate how much PSI you need. The project will as well. Perhaps you want to turn your pressure washer into a sewer jetter. You will need some high-level PSI. Perhaps you want to sandblast your old wheelbarrow a medium to high psi.

How Do You Choose the Right PSI for a Pressure Washer? 

How Do You Choose the Right PSI for a Pressure Washer

I’ve put together a chart below to help you decide the right PSI range, as choosing the right PSI for a pressure washer can be tough. You will be using your pressure washer on a range of things, and each will have different requirements.

Here’s a chart you can use to work out the best PSI for your pressure washing projects:

ApplicationExtra Heavy Duty 3300 PSI + UpHeavy Duty 2900 – 3200 PSIMulti-Duty 500 – 3000 PSI Gas + ElectricMedium Duty 2000 – 2800 PSILight Duty 1500 – 1900 PSI
Car/TruckX
Patio FurnitureXX
SidewalksXXXXX
StairsXXXXX
FencingXXXX
Deck/PatioXXXX
Garage FloorXXXX
DrivewayXXXX
SidingXXX
Stain RemovalXXX
Paint PrepXX
Second StoryX
Power SoapingX

What Is a Good PSI for a Pressure Washer?

What Is A Good Psi For A Pressure Washer

A good PSI for a pressure washer really comes down to what you are looking to achieve. Consumer Reports gives a good breakdown of the pros and cons across the ranges of pounds per square inch and what type of pressure washer will generate the different (PSI) pounds per square inch. A gas-powered pressure washer will usually be regarded as heavy-duty. It will generate anywhere from around 2000 PSI all the way up and over 5000 PSI. These will also demand more (GPM) gallons per minute than the electric powered pressure washers. These will have a PSI range from as little as 800 PSI up to around 3000 PSI, but the GPM won’t match gas pressure washers.

What PSI is Needed to Work on Certain Projects? 

In the chart and sections above, I’ve shown a wide range of projects that you can use your pressure washer for. Here are some of the common projects and there (PSI) pressure washer requirements:

  • Cleaning concrete driveways – 2000 to 3000 PSI 
  • Cleaning vinyl – 1300 to 2500 PSI
  • Cleaning cars – 1200 to 2800 PSI 
  • BBQ grills – 1500 to 4000 PSI 
  • Bikes and scooters – 1500+ PSI 
  • Decks and docks – 2600 to 4000 PSI 
  • Boats or ATVs – 3000 to 4000 PSI
  • Asphalt driveway – 3000 to 4000 PSI 
  • Paint stripping – 4100+ PSI 
  • Wet sandblasting – 2000+ PSI

Hopefully, now you can see the wide range of (PSI) pressure washer demands. You hopefully also see your average electric pressure washer will tackle almost all of the tasks. Paint stripping will require a sandblasting kit for the lower psi ranges.

PSI is an important number, but it’s not the whole story. There are a few other units that you need to take into consideration when purchasing your pressure washer.

What Other Units for a Pressure Washer Might You Want to Be Aware Of?

What Other Units for a Pressure Washer Might You Want to Be Aware Of

The two other units that you need to be aware of when purchasing a pressure washer are GPM (gallons per minute) and CP or CPU (Cleaning Power Units).

GPM or Gallons Per Minute

GPM is the measurement of how much water volume can be delivered in a minute from your pressure washer. This is the number that will tell you how quickly your pressure washer will clean and rinse away any debris.

You want a mix of high PSI and high GPM; sometimes, people think that low GPM is what they need, and that truly isn’t the case. The higher the GPM, the more water comes out of our pressure washer per minute; this results in you finishing whatever pressure washing job you are doing quicker.

Can you supply enough GPM to your pressure washer?

GPM isn’t a number that’s just for your pressure washer. It’s also for you and your outlet. Suppose your pressure washer is rated at 5 GPM, i.e., five gallons of water per minute. In that case, it’s expelling 5 GPM from the spray wand every 60 seconds. To do that, your garden hose needs to supply the pressure washer with five gallons of water per minute. This is a high volume of water.

To find out if you can feed your power washer with the amount of water it wants, take a five-gallon bucket, a stopwatch (your phone has this built-in), and turn your garden hose on full blast.

Place the hose into the bucket and start a stopwatch at the same time.

Wait 60 seconds, then remove the hose and see how much you’ve filled the bucket. If within 60 seconds it’s not full, then work out how many gallons you filled. If you filled only 2 and a half gallons, then you are going to be limited to roughly 2 GPM machines; you want some extra room as the rate of water is never 1oo percent constant, and starving your pressure washer can actually damage it.

If you’ve overflowed the bucket, well, you as good for 5 GPM or more!

CP/CPU or Cleaning Power Units

CP or CPU or Cleaning Power Units is a simple number designed to help level the playing field. It’s difficult to compare two pressure washers when one pressure washer is listed at 2 GPM, 1.2 PSI., and the other is 1.2 PSI and 2 GPM.

So CP was created it’s the multiple of psi and GPM. Simple take your psi and GPM and multiple them together.

PSI x GPM = CP

The higher the cleaning power, the better the pressure washer, well, sort of. Look, you don’t need a 5000 CP pressure washer for washing your deck. Actually, it’ll probably destroy your deck.

Should You Buy, Rent, or Hire Someone to Pressure Wash for You?

There’s some debate about whether you should buy or rent a pressure washer, or even high a pressure washing professional to do the job for you.

The biggest benefit that came from buying a pressure washer was the one time cost and the convenience of it being available whenever I needed it.

Though, if you are intending to make use of pressure washers infrequently, then renting a pressure washer makes sense, it won’t take up storage space, and it’s cheaper than hiring a pressure washing firm.

There are benefits to hiring one of the mange pressure washers firms, you don’t have to do the job, they will have invested in a range of pressure washers or have one which is very adjustable in terms of power and pressure. Meaning they can handle any job you through at them, whether it’s cleaning some decking, removing stains from concrete, or even removing a blockage in your drain.

Personally, I suggest checking out the different types of pressure washers you can get, as you’ll find you can get a good all-rounder, which makes them a very good investment.

What Are the Types of Pressure Washers You Can Get?

Ok, so you know about CP, PSI, and GPM, but there’s more to know. There are types of pressure was, and one type of pressure washer that you can get is a gas-powered one, or you can get electric powered pressure washers.

Both of these types of pressure washers require that uninterrupted steady water supply, which I showed you how to work out what GPM you can supply.

Most people will find that anything from 1300 to 2800 PSI is the perfect range for most home projects, which is why most electric pressure washers sit in that range.

Electric-Powered Pressure Washers

Electric pressure washers are designed for lighter cleaning jobs and range anywhere from 1300 to around 3000 PSI. They’ll also require somewhere around 1.2 – 2.2gpm. Electric-powered pressure washers are much quieter, lighter, and more compact than gas-powered pressure washers, so they are ideal for home use. Most of them also have tanks built-in for detergent use.

When it comes to electric powered pressure washers, I suggest that you hook them up to an outlet that comes with a GFCI (ground fault circuit interrupter). You should always use a 12 or 14 gauge extension cord.

Some electric pressure washers have a GFCI build into their main plug, which is very handy.

Gas-Powered Pressure Washers

Many pressure washers are gas-powered. There deliver much higher PSI ranges, typically over 3000 PSI. However, when it comes to using a gas-powered pressure washer, these heavy-duty machines demand greater GPM. Typically you’ll need around 2 to 3 pm.

These gas-powered pressure washers are designed for bigger and remote jobs, where power isn’t easy to get to.

Are There Special Nozzles for Certain Pressure Washing Projects?

Most pressure washers will come with a range of spray nozzle tips; on the lower PSI ranges, typically under 2400 PSI, you tend to get less of these nozzle tips, or you’ll get a vario wand that has a twist end to switch the spray pattern.

Quick connect nozzle tips give you flexibility over how much force is applied when you are spraying something; the more direct the spray, the higher the force. Some even have a turbo and rotating nozzles. These are amazing are ripping dirt and grime away.

The heavier-duty pressure washer units have 4 to 5 quick connect nozzles. These are color-coded for ease of use. each one will increase the spray pattern degrees, which adjusts the amount of force applied.

The narrower the spray pattern, the deeper and more aggressive the clean.

This table from Lowes gives you a good idea of which are the best pressure washer nozzles for the task you are working on.

DegreeColored NozzleSetting
0 degreeRed nozzleStrongest, concentrated
15 degreesYellow nozzleHeavy-duty cleaning
25 degreesGreen nozzleGeneral cleaning
40 degreesWhite nozzleVehicles, patio furniture, boats, and surfaces which could be damaged easily
65 degreesBlack nozzleLow-pressure for applying soap and cleaning solutions

So we know about the types, the psi, nozzle tips, what rating should you get?!?

What Rating Pressure Washer Should You Use?

What Rating Pressure Washer Should You Use

To make purchasing a pressure washer easy, many stores will give different ratings for pressure washers; this will help you pick the perfect pressure washer for each job.

  • Light-duty – Fantastic for those little jobs around your home (usually between 1300 and 1900 PSI using around 2 GPM). Great for cleaning patios, small decks, vehicles, grills, and patio furniture.
  • Medium-duty – Great for the workshop and for home use (somewhere between 2000 and 2800 PSI and 2 to 3 GPM). Great for cleaning fences, siding, driveways, and walkways.
  • Heavy-duty or Extra-heavy-duty – Great for commercial use (generally 2800 PSI and above at 3 to 4 GPM). Easily the best tool for graffiti removal, paint stripping, washing multi-story homes.
  • Multi-duty – All-in-one pressure washer that you can adjust to your PSI and project-based needs
  • Cold-water pressure washers – Only used for cold water, as hot water could damage them. Great for cleaning mildew, loose paint, dirt buildup, and cars.
  • Hot water pressure washers – Only used for hot water, as cold water could damage them. Great for cleaning farm and industrial products.

Now time for some more terms related to pressure washers that might be handy to know.

What Are Some Other Pressure Washer Terms You May Want to Know About? 

So, I’ve thrown at you a bunch of terms, but here’s some more that might be handy for you to know.

  • Amps (A) – the power output for electric-powered pressure washers
  • Cubic centimeters (cc) – the power output for gas-powered pressure washers engine
  • Axial cam pump – found on many pressure washers made for homeowners, as it’s cheap and reliable, maintenance-free operation
  • Triplex pump – found on higher-end pressure washers made for industrial or commercial use, increases life expectancy and efficiency of the washer.
  • Interchangeable nozzle – accessories, i.e., quick connect nozzles, allow you to adjust the pressure and flow for your pressure washing job.
  • Adjustable wand – anaccessory to help you change pressure and spray pattern while in use
  • Rotating nozzles – accessories that cause the spray pattern to rotate in circular motions

These are just some of the terms you may need to know, but these are important ones to know, as they relate to features you’ll find when you are purchasing a pressure washer.

Talking about purchasing a pressure washer, here are some tips on buying a pressure washer.

What Are the Top Things to Think About When Buying a Pressure Washer?

Before you run off and purchase a pressure washer, there are a few things to consider.

Gas or Electric 

These are two very different types of pressure washers. The strength and speed are the main differences you’ll find between these two.

Gas-powered are stronger, louder, and more robustly built. Electric powered are usually much quieter but produce less power. The electric-powered pressure washers are usually much better for smaller jobs. In comparison, gas pressure washers are better for larger ones.

The majority of homeowners prefer to use electric-powered pressure washers over gas pressure washers as they are quieter. An outlet isn’t far away, usually.

However, for larger jobs, unblocking drains where you need high pressure to clean your drains, or want to clean concrete, you want a gas power washer.

Hot Water or Cold Water 

Pressure washers come in two variants really, you can get a cold water pressure washer. The cold water pressure washers tend not to be as complicated as hot water pressure washers. The cold ones are also usually more portable due to not having to have a hefty boiler.

Hot water models are better at cleaning because of the hot water, hot water helps break down dirt and grease, and are very well suited to farm and industrial use.

Typically a homeowner will get a cold pressure washer. These are more efficient, easy to use, and easy to move around.

Warranty Options

Warranty is hugely important, and you’ll find that there are some different types of warranties available. Ensure that you read the fine print on your warranty to be sure of what your warranty covers. You should know how long the warranty will last and what is covered, i.e., the pump and the engine.

If you have a warranty, the best option is to get your pressure washer serviced under warranty. Here are some questions you should ask:

  • Does it have to be serviced at an authorized repair center? 
  • Do you have to take it to get it worked on? 
  • Are there only fixed set services that will be covered? 

Power Options 

When you get your pressure washer, there are 3 things to pay attention to, PSI, RPM, and CP.

GPM and PSI make it hard to choose the best option, so keep in mind CP, cleaning power is that magic number that makes life easy. You can compare two 4,000 PSI units and their water flow to get a true representation of their cleaning power.

You may find that CU isn’t on the package, but follow my advice of a bit of simple maths to find that number.

Portability 

Portability is a huge consideration. You should care about the portability of the pressure washer. Can you wheel it around easily? If so, that should be a box ticked.

Are There Pressure Washers with Higher PSI Ratings? 

For your average use, anything under 4 000 psi is ideal, let alone 5000, but there are ones that go much, much higher.

  • Under 5000 PSI – low-pressure water cleaning
  • 5000 to 10000 PSI – high-pressure washer cleaning (Commercial grade)
  • 10000 to 25000 PSI – high-pressure water jetting
  • 25000+ PSI – ultra-high pressure water jetting

These are for use in commercial-grade and industrial environments. These are for regular household pressure washing jobs.

Which PSI Pressure Washer is Most Used?

Most people want to choose the best for home projects. The question is, what is the best pressure washer psi? What’s the most used? This would be 3000 PSI. You should keep in mind that an adjustable psi is the best option to adjust the power for your needs.

You’ll find this a common feature on many electric pressure washer models. Gas models also get this to output less pressure.

Is 2000 PSI Pressure Washer Enough for My Home Projects? 

Is 2000 Psi Pressure Washer Enough For My Home Projects

Many electric pressure washer models will give you around 1300-1800 psi with 1.5 GPM. However, most experts (myself included) recommend that you get a model that will produce between 2000 and 3000 psi, with around 2.5 GPM, which will handle most larger home projects.

For the smaller project, a low-pressure model will work. Patio furniture loves up to 2000 psi, but you want a bit more grunt for a versatile machine.

Is PSI or GPM More Important When Choosing a Pressure Washer? 

When you are looking for a pressure washer to buy, these are the same. However, when it comes to the level of importance, PSI is the amount of pressure produced, while GPM is the amount of water used. They are both important when it comes to picking a model to buy or rent.

Can You Use a Stronger PSI Pressure Washer for Smaller Jobs?

I recommend aiming to use a PSI range that fits with that job, but that could mean multiple machines, and that’s not a good idea.

Yes, you can use a more powerful pressure washer for smaller jobs. In a lot of cases, it’ll get the job done quicker. For more delicate items, I suggest increasing the distance between your spray wand tip and the item you are cleaning, as this will reduce the force it suffers.

What Tough Stains Can a Powerful PSI Pressure Washer Remove?

If you have a powerful pressure washer, such as a gas model, then tough stains will be a thing of the past. Some tough stains you’ll easily deal with are:

  • Caked-on mud
  • Mold
  • Hard bubble-gum
  • Dried bird droppings
  • Graffiti

Though you will need a unit with a lot of pressure and cleaning units to remove graffiti.

What are the Best Tips for Keeping Pressure Washing Safe? 

These machines can be dangerous if you aren’t paying attention. So here are some tips to keep pressure washing safe:

  • Lay tarps over plants and utilities around your home to prevent damage
  • Don’t pressure wash homes built before 1977 without having them checked for lead first,
  • Never spray the wand directly onto the siding. Instead, 45-degree angles are often best when pressure washing a home.
  • No matter what you are pressure washing, work on small areas at a time
  • Never spray windows with a pressure washer. The pressure could break your windows.

What precautions Should You Take When Using a Pressure Washer?

What Precautions Should You Take When Using A Pressure Washer

Safety is a must, so before you turn on the machine, I suggest the following:

  • Never point your pressure washer at pets, children, or people in general (this could cut through the skin and cause internal injuries).
  • Wear safety goggles is always recommended.
  • Don’t stand on a ladder when using a pressure washer.
  • Stay at least 6 feet away when you are spraying around electrical outlets or power lines.
  • Before taking off the hoses, turn the machine, water off and squeeze the trigger to get the excess pressurized water out. This isn’t a squirt gun, so don’t point this any anyone.
  • Turn on the safety lock when you aren’t using the pressure washer.

What Should You Do to Prepare Before Using Your Pressure Washer? 

Here are some tips to ensure that you wash safely without causing harm or damage.

  • Turn off all the outdoor electrical outlets. 
  • Avoid higher-voltage areas like an air conditioner.
  • Wear waterproof goggles, gloves, and clothes. 
  • If you see any holes or cracks, these need to be repaired before pressure washing that area.
  • Test an area out of the way to make sure you aren’t going to cause damage.
  • Use a brush on really stained areas.

What Are Some Expert Tips to Pressure Washing Your Home?

If you want to wash your home, these are my go-to tips.

  • Safety should always come first (cover outlets, use tarps, wear appropriate clothing such as goggles, gloves, footwear, etc.).
  • Use the right PSI for the job.
  • Protect bushes and shrubs that may be damaged by high-pressure water.
  • If you have moldy areas on your home, pre-treat these with water and bleach before pressure washing your home.
  • Always test the pressure washer on an out-of-the-way area ahead of time.
  • Point the pressure washer slightly downward to avoid causing damage. 

Does the Diameter of the Spray Hose Matter? 

Most high-pressure hoses are around 1/4 inch for low-pressure models. As you move up and need a higher flow rate, the house will increase to 5/16 inch, and the largest hoses are hitting around 3/8 inch.

You want to take good care of your hose if you want it to last a long time. If your hose becomes damaged, the pressure will be affected, and so will safety.

Closing thoughts

There is a lot of information to digest above, but it’s everything you need to know to ensure that you get the right model with the right pressure and flow rate for you.

You’ll walk away knowing all the terms, how they relate to each other, hopefully knowing that this is a dangerous tool, so care must be taken at all times.

Have a range of tips to ensure that whatever the job, you get it done quickly and efficiently without making common mistakes.

Whether you end up buying or rent a pressure washer or even hire someone to do the job, you’ll now know how to get those pressure washing jobs finished and what to expect of someone.

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