The cost of pressure washer detergent can add up pretty quickly if you use the machine often. After a while, you may be thinking about ways to continue using your pressure washer without emptying your wallet. In fact, you can make a good soap solution using common household items.
From Dawn dish soap to baking soda mixtures, there are a variety of alternatives to using a detergent that works well with a pressure washer. With that said, it’s important to consider sud levels, the pH scale, any additional ingredients, and the formula’s biodegradability before using it with your pressure washer, especially for outdoor projects.
In this guide, we’ll cover the important considerations when choosing a soap as well as ten alternatives to using a detergent with your pressure washer.
Things to Consider When Choosing a Pressure Washer Soap
The practicality of the soap you choose, along with any potential environmental factors it comes with, are all important things to take into consideration before using them.
With outdoor projects, in particular, you have to worry about what the effects of the soap will have in terms of herbicide as well as the amount of time it takes to degrade completely.
Beyond that, consider finding a soap that doesn’t create a ton of suds or has a lot of added ingredients.
Sud Levels
Imagine using a soap mixture with your pressure washer only to find that it leaves an excessive amount of suds behind. Not only will this make clean-up take longer, but leaving suds to sit can cause soap scum and scale to build up over time. To avoid sud levels that are too high, it’s important to follow any instructions very carefully. This way, you don’t accidentally mess up the soap to water ratio in the mixture.
You may also find that some soaps and mixtures have naturally low sud levels, so those are great to use if you don’t want to have to worry about extra clean-up.
pH Levels
Paying close attention to pH levels is important because if you use a soap with a high pH level and it comes into contact with the soil outside or any other biomaterial, it can disrupt the composition of those materials.
For example, a soap with a too high or low pH level seeping into the soil around your house can cause soil erosion and make it difficult for any plants to survive in that soil.
If you like to maintain a healthy landscape or garden on your property, be sure to use a soap with a neutral pH level.
Additional Ingredients
Because soap is meant to kill bacteria and get rid of dirt and grime, it typically comes with additional ingredients that could be harmful to the ecosystem around your house. Most big-name soaps use surfactants in their formulas, which can be harmful to small invertebrates.
Surfactants are the ingredients that reduce the surface tension between oil and water. For small invertebrates that rely on membranes to maintain moisture within their body, coming into contact with a surfactant can be fatal.
Biodegradability
Now, more than ever, there has been a push to make products more easily biodegradable. While you may not think about soap and how long it takes to break down, it can take at least six months to dissipate completely.
Using a soap solution that is fully biodegradable not only helps the ecosystem on your property but also helps you reduce your carbon footprint too.
10 Alternatives to Using Detergent in a Pressure Washer
To avoid the risk of messing with the pH levels around you, and to prevent spending more money than you need to, you may want to consider some alternatives to using a detergent in your pressure washer. While there are a plethora of alternatives to choose from, we’ve come up with ten excellent alternatives that are proven to work.
With that said, each alternative has its own instructions on how to use it with a pressure washer, so it’s important to follow those instructions carefully.
1. Dawn Dish Soap 
To use Dawn dish soap with your pressure washer, you need to make sure the soap is properly diluted to avoid excessive suds and potential harm to the soil outside. Mix one tablespoon of the liquid dish soap with between one and 1.5 quarts of hot water. The great thing about Dawn dish soap is that it’s easy to find at just about any convenience or grocery store.
With that said, you may find that Dawn dish soap isn’t as effective after the first wash as a detergent or other solution may be. Because of that, you might need to perform a second wash to get the results you desire.
RELATED ARTICLE: Can You Use Dish Soap in a Pressure Washer? (How to Dilute)
2. Simple Green All-Purpose Cleaner
Simple Green all-purpose cleaner is an all-purpose cleaner formulated by Simple Green, a leader in the safer product development and sustainability industry. This particular cleaner is safe for use in pressure washers as well as any washable surface that needs cleaning. Despite the fact that it doesn’t have any caustic chemicals other brands use to fight dirt and grime, this all-purpose cleaner can get the job done.
To use this cleaner, you need to decide the level of clean you want to achieve: light cleaning, general-purpose, or heavy-duty. The great thing about this cleaner too is that it doesn’t necessarily require dilution if you want a full-strength clean. The dilution method needed for each of these cleaning levels is as follows:
- Light Cleaning: 1:30 dilution of cleaner to water
- General Purpose: 1:10 dilution of cleaner to water
- Heavy Duty: 1:1 dilution of cleaner to water
3. Baking Soda Solution 
A baking soda solution is an excellent alternative to a store-bought soap or cleaner. To use baking soda with your pressure washer, you should use one part baking soda to eight parts water. It’s generally best to use the hot water setting with the pressure washer as it can clean deeper and more effectively than with cold water. When adding the baking soda, you can either mix it right in with the water or pour it into the chemical attachment on the machine.
4. Vinegar
Vinegar is another natural solution to store-bought soaps or cleaners. However, you need to be careful not to mix vinegar with a chemical cleaner, like bleach, because it can release toxic fumes that can make you incredibly sick. For that reason, you should use this solution to clean up paint or oil spills, or any other mess that involves unknown chemicals.
For other clean-up situations, the vinegar to water dilution ratio varies depending on the level of cleanliness you’re looking for. Here’s a helpful cheat sheet to give you a better idea of what the dilution level is that you need:
- Mild cleaning: 10:1 ratio of water to vinegar
- Mildew and tough stains: 6:1 ratio of water to vinegar
- Deep cleaning: 3:1 ratio of water to vinegar
5. Briggs & Stratton Multi-Purpose Cleaner
This multi-purpose cleaner by Briggs & Stratton is an affordable alternative to using detergent in a pressure washer. The cleaner is easy to use and comes with specific instructions for diluting it down based on what kind of clean you’re looking for. The cleaner is also guaranteed to be safe for grass and plants in the event that it runs off into your soil. For tough cleans, mix this cleaner with a 1:1 ratio of cleaner to water.
6. Liquid Laundry Detergent Solution
Laundry detergent is perfectly acceptable to use in a pressure washer as long as you make sure the detergent has to be mixed completely with the water before use. Because it’s a thicker solution, it can cause clogs if you don’t wait long enough to use it.
You should also make sure the laundry detergent you’re using doesn’t have any phosphates in the formula. These are harmful to the environment and they can also cause issues with your machine. To use this method, mix one cup of detergent with one gallon of water before adding it to your pressure washer.
7. Powder Laundry Detergent Solution
Just like with liquid laundry detergent, you need to ensure powder laundry detergent is dissolved completely before using your pressure washer. To use this method, mix ¾ cups of powder laundry detergent with one gallon of warm water in a separate bucket.
Mix the solution together and add the mixture into the pressure washer once everything is mixed fully. Remember to run water through your garden hose on the area after you finish to wash away the soap mixture.
8. TSP Cleaner
Trisodium Phosphate, or TSP, is a cleaner that is similar to powder laundry detergent. If you’re just doing a general clean, you can mix ½ cups of TSP with one gallon of water. After spraying the area, it may also be helpful to scrub with a hard-bristled scrub brush before rinsing.
If you’re trying to go for a deeper clean, mix one quart of household bleach, two ounces of TSP, and three quarts of water. If needed, you can cover the area for around an hour to ensure all mold, mildew, and other grime is cleaned off before spraying the area down with a hose.
9. Borax Solution
Borax is a common cleaning agent in many household cleaners. It’s also an excellent tool to use for softening water and cleaning your laundry. Its coveted reputation makes it an excellent alternative to pressure washer detergent when you want to use your pressure washer. To use this method, you should mix together one gallon of water, ½ cups of Borax, ½ cups of washing soda, and one tablespoon of liquid dish soap.
10. Car Shampoo
You can certainly use normal car shampoo in your pressure washer, but there are a few things to keep in mind before doing so. If your pressure washer isn’t specially designed to handle the consistency of car shampoo, you may not have much luck getting a good clean.
However, many people who use car shampoo in their pressure washer say it can be done as long as you dilute it properly. Depending on the shampoo you have, it may already be semi-diluted and won’t need any more added water.
Final Thoughts
As spring makes its way into the atmosphere, the spring cleaning bug has hit households everywhere. During this time, people are taking advantage of the warming temperatures and giving their exterior home siding the power wash they’ve been waiting all year for. From dirt and grime to salt build-up during the winter, pressure washing your property is a great way to start off the spring season the right way.
Regardless of which alternative method you choose, we hope this article has been helpful in choosing which method fits you best.
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Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.