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How To Choose The Right Pressure Washer Detergent

A pressure washer is an extremely efficient cleaning tool. You could technically use only water and would get a decent cleaning job simply from the blast coming from water sprayed. However, at some point in time, it would be a good idea to get familiar with pressure washer detergents.

There’s a variety of pressure washer detergents you can choose from. They range according to the type of cleaning job you’ll be taking on. Some are more specialized in function than others. For example, grease and oil stains require specific formulated solutions to be effective. Mold and mildew on the other hand, require a different kind of mixture to disinfect.

How does one go about choosing the right pressure washer detergent to use? Read on as I give you a run down on what’s out there and what they’re used for. I’ll even introduce some environmentally friendly cleaning solutions, as well as a simple method of making your own.

Types Pressure Washer Detergents

The table below gives an overview of the different types of detergents that you can use. As you can see, they are typically categorized according to what kind of surface they are to be applied on. Generally, multi-purpose detergents are sufficient to use for most cleaning jobs.

Type of DetergentUse 
General all-purpose cleanersGood for cleaning most stains and grime
DegreasersGood for caked-on grease and oil stains
Vehicle detergents Good for cleaning boats, cars, and other vehicles
House cleaning detergentsGood for cleaning dirt off the siding of homes 
Deck and fence cleaning detergentsGood for cleaning decks and fences 
Specialized solutionsRead the specific label to know what it is used for

All-purpose detergents

You’ll find these in most local hardware and department stores. They’re good for almost any kind of pressure cleaning task you’ll be working on. These detergents can handle dirt, grime and other stains you might have. 


Degreasers are made to remove the caked-on grease and oil stains. They are very useful in working with tough floors, such as those in automotive shops and restaurants. You can use some of the degreasers on vehicle engines and heavy equipment.

Vehicle detergents 

Vehicle detergents, such as those for boats, cars, and other are specialized, as well. Detergents for boats need to handle algae and salt water deposits. Detergents for cars need to handle dirt, salts, and road film. 

It is important not to mix these up. Detergents that are made for heavy-duty equipment could ruin the paint or aluminum on a car, for instance.

House cleaning detergents

There are detergents made for cleaning houses, too. There is often dirt ingrained into the siding. The detergents are made for cleaning off the dirt while preventing fading of the color and avoiding damage. 

Deck and fence detergents

You will find there are also deck and fence detergents. These are just what they sound like, for cleaning decks and fences. These aren’t quite as harsh as the vehicle detergents and degreasers. Wood can be damaged more easily than other more dense materials.

Specialized solutions

You will also find specialized solutions. These have warning labels that you should follow very closely. They will say what you can and can’t use the solution on.

This is just the basics of the different types of detergents you can use with your pressure washer. There are many formulas available and different detergents for various needs. 

The Case for Using Pressure Washer Detergent

Many people aren’t sure if they even need to use pressure washer detergent. For the most part, yes, you should get detergent for your pressure washer cleaning projects. The cleaning results will be better and you can clean quicker, as well. 

Soaps and detergents help to get mildew, grease, grime, and dirt off from whatever you are working on. In addition, you won’t have to work on cleaning the same spot for as long when you use detergents and soaps. However, it is essential to make sure you are using the proper detergents and soaps with any specific application, to prevent damage. 

Detergent Preparations

You can pressure wash with just water, but you could accomplish so much more with detergent and the right cleaning agents. Think about it for a moment. Will pressurized water completely remove grease and oil? How about mold and mildew? Need a degreaser or disinfectant?

Pressurized water in combination with special formulated detergents can give you a more effective cleaning solution. However, you need to know how to prepare such detergents for use. Consider what detergents you will be using and how it will be delivered through your washer pump.

Tank or tankless

There are a couple of ways pressure washer detergents are prepared before use. Some washers have on-board detergent tanks and others don’t. There’s also different delivery detergent methods.

The first thing you need to do is mix the detergent concentrate. Follow the instructions given by the manufacturer for the proper water to detergent ratio to use.

Most residential use pressure washers have built-in detergent tanks. So you would simply pour the detergent mix into the tank before using. Then it is injected through the pump with some water. The water and detergent are pressurized together and released from your spray gun. 

This is the easiest and most common way to load your washer with detergent.

Some of the more powerful and industrial models are tankless. You would need a siphon hose to vacuum the detergent from it’s container to the washer.

Premixed or concentrate

Some detergents are premixed. But a lot are sold in concentrate form. Look at the manufacturer label before using. If there are mixing instructions then it’s a concentrate. Follow the proper ratio of water to concentrate.

Upstream or downstream

There are two methods of delivery that are used to transport the detergent to the washer: upstream and downstream. It’s just a matter of preference. Some people think one works better than the other.

Upstream delivery has the cleaning agents go through the pump and several other washer components. With this, you get more pressure and marginally higher temperatures. However, the chemicals may damage the components in time.

Downstream delivery has the cleaning agents brought into the washer without clearing the pump. If there are chemicals you need to use that may be too hard on your pump, such as bleach as one example, this would be the way to go.

Copyright protected content owner: and was initially posted on September 4, 2019.

Just be careful when using chemicals, especially with a downstream injector. When a diluted bleach solution is being considered, the opinions on the Internet are really mixed. Some say it’s fine and that with a downstream delivery the bleach doesn’t go through the pump so it won’t corrode. Others are adamant in saying never because other metal components, o-rings, and wand still touch bleach and will get corroded.

Cleaning agents

There’s a variety of cleaning agents that can go into making a pressure washer detergent. It really depends on the job and the type of surface that will be cleaned. Some are formulated to remove greasy residue while others are designed to disinfect. Check out some of the commonly used chemicals you’ll find in detergents.

  • Vinegar Polishing surfaces such as door handles
  • Citric acid – Cleaning wood decks and concrete driveways
  • Oxalic acid – Removing rust and cleaning other projects 
  • BleachAggressive disinfectant and sanitizer
  • Sodium hypochlorite – Removing powerful stains and disinfecting 
  • Sodium hydroxide – Removes grease and fats, great for cleaning steel
  • Ammonia Great for cleaning stainless steel.

Pre-treatment & Disposal

Depending on the type of surface, you are working with you may need to start by pre-treating it before soaping up. You can treat the spots that are a bigger issue and then soak them with the hose before starting with your pressure washer. 

Soaping tips


There are some tips for effective soaping that you should know about, as well. These include the following:

  • Start from the bottom and work upward – to prevent streaking 
  • Overlap applications – this way you don’t miss any spots
  • Let your solution sit for 5 to 10 minutes – don’t let the solution dry, though
  • Rinse the detergent off from top to bottom
  • Take off the foam nozzle or turn off the tank valve
  • Put on the rinsing proper nozzle and finish pressure washing project 

Foamers and soap shooters 

If you need a way to spray chemicals and detergents without them going through the pump, soap shooters and foamers are exactly what you need. They connect to one end of the spray gun. You will then inject your solution into the stream of water being released. 

The foamers generally have reduced pressure. Soap shooters are very similar, but they have higher pressure and can be used for longer distances. 


There are 2 types of foamers. One has a spray nozzle that is connected to a siphon tube to get the detergent out of your bucket. The other type allows you to attach a detergent bottle onto the spray gun, so you can move around better. 

Soap Shooters

You can only get soap shooters with a siphon tube and spray tips. The spray nozzle is adjustable and can be attached to the end of a lance. Soap shooters are excellent for cleaning your home’s siding. 

Disposal tips

It’s important to know how to properly dispose of pressure washer detergents. Some are not as environmentally friendly as others. If the detergent has some harmful or caustic cleaning agents, be careful when handling and disposing, especially when there’s children or pets around.

  • Always check the composition thoroughly 
  • Fines can be given for improper waste water discharge 
  • With chemicals, always discharge into sanitary sewers 
  • If in doubt, check with the city about proper disposal methods

Best Mixtures for Pressure Washing 

Pressure washer cleaning solutions don’t come cheap. If you find yourself frequently using your washer, it might be a better idea to start making your own detergent. Fortunately, it’s not that difficult to do, and there’s a bunch of resources on the Internet that teach you how to do it. The most common ingredients to use are white vinegar, bleach and dish soap/laundry soap.

White vinegar and water

Most people have white vinegar somewhere around the house. It’s used to clean things like floors and bathrooms. In general, vinegar is a great natural disinfectant.

For pressure washers, prepare a vinegar mix of 7 part water to 3 part vinegar. Use it to kill mold and mildew. This solution is natural and environmentally friendly. It’s not too terrible on plants and vegetation, but you should still take caution and maybe cover those before pressure washing.

Bleach and water

Mold and mildew are often cleaned with bleach solutions. It’s a little stronger than your vinegar cleaning solutions. Bleach in your pressure washer is certainly a viable option. Just be careful with yourself in handling and with the washer while it’s dispensing.

Bleach can be a dangerous substance. It needs to be diluted before use. Most pressure washer bleach mixes have it at 3 parts water to 1 part bleach. You can also work with a ratio of 4 parts water to 1 part bleach. Either or is fine.

Never have bleach running straight through your washer and pump. You’ll want a downstream chemical injector that will dispense and mix the bleach solution with the pressurized water after the pump. This way you don’t damage the washer.

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Soap mixture

A basic soap mix can be made from household items. One popular DIY pressure washer recipe has you mixing in a bucket 1/3 cup phosphate-free laundry soap, 2/3 cup powdered household cleaner and 1 gallon water.

You can use this soap mixture as an all-purpose cleaning solution. It’s not harsh, so you can apply it on all different kinds of surfaces.

The Cleaning Process

Setting up your pressure washer and soaking the surface with detergent and soap is pretty straightforward. Just prepare the cleaning solution, use the black nozzle, and spray. After the detergent/soap has soaked, switch to a high-pressure nozzle to rinse off. Here is the overview of the steps involved.

  • Fill your detergent tank or prepare your siphon
  • Turn the detergent tank valve on
  • Get the low-pressure black nozzle
  • Spray surface from bottom to top 
  • Overlap every pass, so nothing is left untreated 
  • Leave on for 5 to 10 minutes, without letting it dry
  • Turn detergent tank valve off 
  • Squeeze the rest of the detergent out of your line
  • Change the nozzle to high-pressure one
  • Rinse off detergent and grime from the top to the bottom

Detergents and Soaps 

I think most people have the belief that detergents and soaps are one in the same. However, this is not exactly true. They are a little bit different in their makeup and applications.


Detergents are made by man and aren’t exactly biodegradable. This means you shouldn’t let them go down storm drains or any type of drain. They need to be properly disposed of them. The good news is that detergents can be used with any kind of water solution. You don’t need to worry about blockage in your pressure washer. 

Detergents can be harsher on surfaces than soap. It depends on the chemical makeup. So be careful and look at the manufacturer labels for their intended use. The chemical composition for cleaning fiberglass might look very different from that for cleaning wood, for example.


While soap is technically a type of detergent, it is a dissolving agent as well. Most soaps made for pressure washers are natural. You can put them in water without much worry. However, you should still check the ingredients to assure you can put the water down the storm drains. 

If you have a light cleaning project, soap may be your best choice. It’s a cost-effective solution and it’s easy to use. Most electric pressure washers can handle different kinds of soaps. Just be careful that the soap does not create any blockage.

Detergent vs soap

Figuring out what surface you’ll be cleaning is the first step. Then you’ll have to be aware of specific stains and what kind of treatment they’ll require. After these two points have been addressed, you can move on to decide whether to use a specialized detergent or soap.

There are many choices you have when it comes to using detergents and soaps with your pressure washer. It is essential to know how each product works in your pressure washer and to know the difference between them, as well. 

You’ll find that there many detergents and soaps on the market. Some will be consumer grade and others will be designed for commercial use. You’ll also find some that are pre-mixed and some that are in concentrate form.

Difference Between Commercial and Consumer Soaps

The main difference between commercial and consumer detergents and soaps is the amount of concentration they have. 

Consumer detergents and soaps are often pre-mixed while commercial professionals often buy concentrated detergents or soaps in bulk. 

While you will need to mix consumer soap with water, the commercial soaps need even more water to reach the proper concentration. In addition, commercial detergents and soaps are usually sold in large containers, barrels, or tubs. 

Unless you are commercial business or plan to pressure wash everyone’s house that you know, you will probably only need consumer detergents and soaps. In addition, you can find consumer detergents and soaps that are commercial-grade formulas. These eliminate the need to buy commercial detergents and soaps. 

Hard Water and Soap Usage with Pressure Washers

When you are thinking about using soap for your pressure washer projects, you also need to think about the type of water you are using. The con with using soap is that you shouldn’t be using hard water with it. This can cause the dirt, grime, oil, or whatever else you may be cleaning to be even tougher. 

However, when you are using chemical detergents, the type of water won’t matter as much. Hard water doesn’t react the same with chemical detergents, as it does with soap. With that being said, detergents shouldn’t be run from the sewer system or with groundwater. 

Basically, the soaps are used for handling grime and dirt. Detergents are made more for disinfecting and sanitizing. However, there are still detergents that can be used for cleaning, too.

Final Thoughts

Detergents are very powerful when you are trying to complete a pressure washing job. You can take the worst of stains and detergents will help you to get them off. This includes grime, mildew, dirt, oil, grease, and more. When detergents are used in a pressure washer, you can get the most out of your cleaning job. 

Now that you know more about the types of detergents and soaps you can use, how to make homemade detergent, what type of water you should use and shouldn’t use, information about the detergent tanks, and more, you can choose the right pressure washer detergent or soap that you need. 

ReadyToDIY is the owner of this article. This post was published on September 4, 2019.

This is the ultimate informative guide for pressure washer detergent. You can now take on any pressure washing project. Whether you need to clean oil, grime, dirt, or anything else, you can take over the project and get it done.