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 the chemical bond between the surface and the stain, 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?
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:
| Use | 3300 PSI + Up | 2900 – 3200 PSI | 1000 – 3000 PSI | 2000 – 2800 PSI | 1500 – 1900 PSI |
| Car/Truck Cleaning | X | X | X | ||
| Patio Furniture Washing | X | X | |||
| Sidewalk Cleaning | X | X | X | X | X |
| Exterior Stairs | X | X | X | X | X |
| Fencing | X | X | X | ||
| Decking and Patios | X | X | X | ||
| Garage and workshop floors | X | X | X | X | |
| Concrete driveways | X | X | X | X | |
| House siding | X | X | X | ||
| Concrete stain removal | X | X | X | ||
| Paint Preparation | X | X | X | X | |
| Second story cleaning | X | X | X | X | |
| Power Soaping and foam cannons | X | X | X | X | X |
So what’s 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 – 1200 to 2800 PSI
- Cleaning cars – 1200 to 2800 PSI
- BBQ grills – 1500 to 3000 PSI
- Bikes, scooters or ATVs – 1200+ PSI
- Decking – 1200 to 2800 PSI
- Boats – 2000 to 3000 PSI
- Asphalt driveway – 1800 to 3000+ PSI
- Paint stripping – 2000+ PSI (Wet sand blasting enables this at lower PSI ranges)
- Wet sandblasting (Rust removal) – 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. Sun Joe have some great options.
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.
So we know PSI but what other Units should you be aware of?
The two other units that you should to be aware of when purchasing a pressure washer are GPM (gallons per minute) and CP (Cleaning Power).
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 represents that water flow and that tells you how quickly your pressure washer will 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 – Cleaning Power
CP also knows as 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.
Buy, Rent, or Hire Someone to Pressure Wash for You?
There’s some debate about whether you should rent or even buy a pressure washer, or even higher a pressure washing professional to do the job for you.
The biggest benefit that came from buying a pressure washer is a one time cost and the convenience of it being available whenever you 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.
| Nozzle Degrees | Nozzle Color | Nozzle Purpose |
| 0 degrees | Red nozzle | Strongest, and most direct and concentrated spray pattern |
| 15 degrees | Yellow nozzle | Aimed at heavy duty cleaning, a very strong spray pattern |
| 25 degrees | Green nozzle | Ideal for general cleaning |
| 40 degrees | White nozzle | A softer approach, ideal for patio furniture, boats, cars, trucks etc, and other surfaces which could be damaged easily |
| 65 degrees | Black nozzle | A very Low-pressure nozzle designed mostly for applying soap and other cleaning solutions |
So we know about the types, the psi, nozzle tips, what rating should you get?!?
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 usually between 1300 and 1900 PSI using around 2 GPM. These are great for cleaning patios, small decks, bbq grills, vehicles, and patio furniture.
- Medium-duty – Great for the workshop and for home use (somewhere between 2000 and 2800 PSI and between 2 to 3 GPM). The are fantastic for cleaning siding, driveways, walkways and fencing.
- Heavy-duty or Extra-heavy-duty – Aimed at commercial use (usually at least 2800 PSI and above at 3 to 4 GPM). Easily the best tool for graffiti removal, paint stripping, and washing multi-story homes.
- Multi-duty – And ideal choice for a home owner as these are an all-in-one pressure washer. You can adjust the PSI to match the needs of the project.
- Cold-water pressure washers – As the name suggests, just for cold water, never use hot water as that could damage them. Great for loose paint, cleaning mildew, dirt buildup, and cars.
- Hot water pressure washers – 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 any electric-powered pressure washers
- Cubic centimeters (cc) – the power output from your 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 to match the requirements of the pressure washing job.
- Adjustable wand – A bit like a hozelock or gardena trigger, this allows you to change the pressure and spray pattern when 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?
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, its at this level that these really become effective cleaning units.
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 or perhaps commercial grade pressure washers, 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 oil stains will need pre-treatment
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, grasses and utilities around your home to prevent damage and overspray.
- If you house was built before 1977 have them checked for lead first before you pressure wash them.
- Never spray the wand directly onto the siding, this can cause splash back onto you exposing you to chemicals. Instead, I suggest using a 45-degree angle when pressure washing a home.
- Work small areas at a time
- Never spray windows with a pressure washer. The pressure could break your windows and having done it, it never cleans them.
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’s spray nozzle near pets, children, or people in general (the pressure can penetrate through the skin and cause internal injuries).
- Wearing safety goggles is always a good idea.
- Don’t stand on a ladder when using a pressure washer, the kickback can knock you off.
- Stay a good distance such as 6 feet away from electrical outlets or power lines when you are using a pressure washer even it’s a very low pressure model.
- Before disconnecting the hose, turn the machine and water off, squeeze the trigger to remove the excess pressurized water out. This isn’t a squirt gun, so don’t point this any anyone.
- Ensure the safety lock is on when you’re not 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.
- Isolate and turn off all the electrical outdoor outlets.
- Avoid spraying near higher-voltage areas such as an air conditioner.
- Wear waterproof clothing such as trousers and gloves.
- repair any holes or cracks, prior to pressure washing that area.
- Test an area on an out of the way part of your home to make sure you aren’t going to cause damage.
- Use a brush on really stained areas to help create more cleaning power.
What Are Some Expert Tips to Pressure Washing Your Home?
If you want to wash your home, these are my go-to tips.
- Safety always comes first so cover your outlets, wear appropriate clothing such as goggles, gloves and footwear and use tarps.
- Use the right pressure washer at the right PSI for the job.
- Protect shrubs and that could be damaged by high-pressure water from power washers
- If you identified mold or mildew around your home, it’s best to pre-treat these with a light bleach solution before pressure washing your home.
- Always test your pressure washer on an a small out of sight area ahead of time to ensure no damage.
- Point the pressure washer slightly downward to avoid splash back onto yourself.
- Use adjustable nozzles as these spray nozzle attachments will help regulate pressure output, perhaps look to use the low pressure nozzle.
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 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 renting a pressure washer, you’ll now know how to get those pressure washing jobs finished and what to expect of someone.
