You have just spent hours under the sun, scrubbing your driveway with a brush, only to find that stubborn oil stains remain. Or maybe you are staring at your vinyl siding, wondering why the green algae keeps coming back. Pressure washers are powerful tools, but without the right cleaning solution, they are just spraying water. That is where the best cleaning products for pressure washers come in. This guide covers the top detergents and concentrates that turn your washer into a deep-cleaning machine. We evaluated formulas from SimpleGreen, Zep, Kärcher, and Krud Kutter to help you choose the right one for your home. For more on maintaining your home’s exterior, check out our guide on best 16x25x5 air filters for home furnace.

1
Best Seller

Simple Green Pro HD Heavy Duty Cleaner Concentrate

SimpleGreen
9.8 /10
YPS Score
YPS score rating is a scoring system developed by our experts. The score is from 0 to 10 based on the data collected by the YPS tool. This score doesn't impact from any manufacturer or sales agent websites. Learn more ›
Simple Green Pro HD is a professional-grade, concentrated cleaner and degreaser that tackles tough grease and grime on multiple surfaces. Ideal for contractors, automotive, and industrial use, it is biodegradable and safe on metals.
Pros & Cons

Pros

  • Highly concentrated – one gallon makes up to 64 gallons of cleaner.
  • Non-corrosive and safe on metals, plastics, and carpets.
  • Biodegradable and unscented, suitable for sensitive environments.
  • Versatile – works for automotive, industrial, commercial, and household use.
  • Backed by thousands of positive reviews from professionals.

Cons

  • Contains Propylene Glycol Butyl Ether and Triethanolamine, which may trigger Prop 65 warnings in California.
  • Unscented formula may lack the fresh scent some users prefer.
  • Requires dilution for most uses, adding a step for those wanting a ready-to-use product.
Detailed Review

Simple Green Pro HD Heavy Duty Cleaner Concentrate is a professional-grade product designed for contractors, industrial facilities, and serious DIYers. It tackles tough grease, grime, and stains on a wide range of surfaces including floors, walls, equipment, appliances, and vehicles. This concentrated formula is a workhorse for pressure washing, parts washing, and ultrasonic cleaning.

What sets this cleaner apart is its non-corrosive nature and safety on metal surfaces, making it ideal for automotive and industrial applications. Users report excellent performance on engine parts, kitchen grease, and even carpets. The biodegradable, unscented formula is a plus for environmentally conscious users and those sensitive to fragrances.

The product comes in a sturdy 1-gallon jug with a handle for easy pouring. As a concentrate, it requires dilution according to the task, which is straightforward. The lack of strong odors makes it comfortable to use in enclosed spaces. The brand Simple Green is trusted by professionals, and this Pro HD version lives up to that reputation.

One drawback is that it contains ingredients that trigger California's Prop 65 warning, which may concern some users. Additionally, it is unscented, so if you prefer a fresh citrus or pine scent, this won't provide that. The need to mix your own solution might be inconvenient for those used to ready-to-use sprays.

Overall, Simple Green Pro HD is a top-tier cleaner and degreaser that delivers on its promises. With thousands of positive reviews and a high rating, it is a reliable choice for heavy-duty cleaning tasks. Its versatility, safety, and eco-friendly profile make it a solid investment for any professional or homeowner looking for serious cleaning power.

2
Editor's Pick

Zep All-in-1 Premium Pressure Washing Concentrate

Zep
9.7 /10
YPS Score
YPS score rating is a scoring system developed by our experts. The score is from 0 to 10 based on the data collected by the YPS tool. This score doesn't impact from any manufacturer or sales agent websites. Learn more ›
This pro-grade concentrate tackles tough outdoor stains like algae, mold, and mildew, restoring surfaces without harsh scrubbing. Perfect for homeowners who want a powerful, versatile cleaner for siding, decks, patios, and vehicles.
Pros & Cons

Pros

  • Versatile cleaner suitable for many outdoor surfaces including wood, brick, and siding.
  • Highly effective at removing algae, mold, and mildew stains with minimal effort.
  • Concentrated formula provides excellent value for large cleaning projects.
  • Positive user feedback highlights ease of use and streak-free results on windows and decks.

Cons

  • Some users note it is not a miracle product; stain removal can be average on very tough set-in grime.
  • Requires a pressure washer for best results; not designed for manual scrubbing applications.
  • Unscented formula may not appeal to those who prefer a fresh scent during cleaning.
Detailed Review

The Zep All-in-1 Premium Pressure Washing Concentrate is a versatile outdoor cleaner designed to revive surfaces dulled by weather, mold, algae, and pollen. Ideal for homeowners with pressure washers, it tackles stains on siding, driveways, brick, wood, stucco, and even outdoor furniture and vehicles. This pro-grade formulation aims to simplify outdoor cleaning with a single, concentrated solution.

Standout features include its ability to remove common outdoor stains such as dirt, algae, mold, and mildew without aggressive scrubbing. Real-world performance from user reviews is generally positive, with many noting excellent results on decks and windows. One 74-year-old user praised its ease of use and streak-free shine on windows after applying the soap and rinsing. However, a minority of reviewers found it to be an average cleaner, not a magic solution for deep-set stains.

Build quality is solid; the bottle is described as hardy and leak-proof, with an easy-to-open lid. The 172-fluid-ounce concentrated liquid offers good value for large projects. The unscented formula is a practical choice for outdoor use, avoiding lingering chemical smells. Overall design prioritizes functionality and convenience.

A potential drawback is that results may vary depending on the severity of stains and pressure washer equipment. While effective for regular maintenance and light to moderate stains, it might not eliminate deeply embedded grime in a single wash. Users seeking a single-step miracle cleaner may be disappointed, but for routine outdoor cleaning, it performs reliably.

Verdict: The Zep All-in-1 Premium Pressure Washing Concentrate is a strong choice for anyone with a pressure washer who wants an all-purpose cleaner that handles algae, mold, and mildew on multiple surfaces. It offers good value, ease of use, and consistent results, though it may require additional passes for tough stains. Recommended for homeowners looking to simplify their outdoor cleaning routine.

3
Limited Time

Zep 128 oz House & Siding Pressure Wash

Zep
9.6 /10
YPS Score
YPS score rating is a scoring system developed by our experts. The score is from 0 to 10 based on the data collected by the YPS tool. This score doesn't impact from any manufacturer or sales agent websites. Learn more ›
Zep House & Siding Pressure Wash Concentrate is a professional-grade, biodegradable formula that removes algae, mold, and mildew from siding, roofs, and brick. It is ideal for pressure washer users seeking an effective exterior cleaner.
Pros & Cons

Pros

  • Concentrated for long-lasting use and value.
  • Powerful stain removal for algae, mold, and mildew.
  • Compatible with multiple surface types.
  • Eco-friendly biodegradable formula.
  • Trusted brand with high customer satisfaction.

Cons

  • Requires a pressure washer for application; not for use without one.
  • Heavy stains may require pre-treatment or multiple applications.
  • Not recommended for all exterior materials; test on a small area first.
Detailed Review

Zep House & Siding Pressure Wash Concentrate is a professional-grade exterior cleaner designed for use with pressure washers. It is ideal for homeowners and contractors looking to restore the appearance of siding, roofs, and other outdoor surfaces.

This concentrated formula makes up to 20 gallons of cleaning solution, offering excellent value. It effectively removes unsightly stains caused by algae, mold, and mildew, helping to brighten and restore curb appeal. The biodegradable formulation is an eco-friendly choice.

Users report impressive results on a variety of surfaces, including vinyl siding, brick, stucco, and wood. The cleaner works quickly with a pressure washer, reducing the need for scrubbing. However, heavily stained areas may require a second application.

The main limitation is that it requires a pressure washer; it is not a ready-to-use spray. Additionally, users should test on a small hidden area first to ensure compatibility with their specific surface. Some may find the price per bottle higher than basic cleaners, but the concentration offsets cost.

Zep House & Siding Pressure Wash Concentrate is an effective, eco-friendly solution for exterior cleaning. Its powerful stain removal and versatility make it a top choice for anyone with a pressure washer. Highly recommended for restoring outdoor surfaces.

Specifications

Product Dimensions: 6.02 x 6.02 x 12.13 inches

Weight: 8 pounds

Item Model Number: ZUVWS128

Material Feature: Biodegradable

Manufacturer: Zep

ASIN: B00G5KHWZA

4
Top Rated

KÄRCHER Multi Purpose Pressure Washer Detergent

Kärcher
9.6 /10
YPS Score
YPS score rating is a scoring system developed by our experts. The score is from 0 to 10 based on the data collected by the YPS tool. This score doesn't impact from any manufacturer or sales agent websites. Learn more ›
This highly concentrated pressure washer detergent from KÄRCHER dilutes to make up to 20 gallons of ready-to-use cleaner, effectively cutting cleaning time on decks, driveways, and siding. It works well with most consumer pressure washers, making it a versatile addition for homeowners who want faster, more thorough results.
Pros & Cons

Pros

  • Highly concentrated: one bottle equals 20 gallons of ready-to-use solution
  • Works well with multiple pressure washer brands, not just KÄRCHER
  • Effective on a wide range of outdoor surfaces including wood, concrete, and vinyl
  • Saves time by helping the pressure washer clean more quickly
  • Trusted by over 5,000 reviewers with a 4.4 average rating

Cons

  • Must be manually mixed with water before use, which adds a small step
  • Not recommended for commercial-grade pressure washers or extreme grime removal
  • Only intended for use with pressure washers, not for bucket or spray bottle cleaning
Detailed Review

The KÄRCHER Multi Purpose Pressure Washer Detergent is a highly concentrated soap designed to make outdoor cleaning faster and more effective. It’s ideal for homeowners who regularly clean decks, driveways, siding, and other outdoor surfaces with a pressure washer. With a rating of 4.4 out of 5 stars from over 5,300 reviews, it’s a proven performer in the consumer pressure washer detergent market.

Standout features include the ability to make up to 20 gallons of ready-to-use cleaner from a single bottle. The concentrated formula allows you to adjust the dilution strength based on the job, whether you’re tackling light dust or stuck-on grime. Many users report that it noticeably reduces cleaning time compared to using water alone, thanks to its specialized cleaning agents that work with both cold and warm water pressure washers.

Design and build quality are straightforward: the detergent comes in a sturdy, resealable container with clear measuring marks. It’s compatible with all KÄRCHER Home & Garden models as well as most other consumer pressure washers, which adds wide usability. The bottle’s 8.25-pound weight is manageable, and the size fits well on most pressure washer carts or storage shelves.

Potential drawbacks are minor: you must mix the concentrate with water before each use, and it’s not intended for commercial-grade machines or ultra-heavy-duty industrial cleaning. A few users noted that it may leave a slight residue if not rinsed thoroughly, but proper application avoids this. Overall, the product delivers reliable performance for everyday residential cleaning tasks.

Our verdict: If you own a consumer pressure washer and want a cost-effective, time-saving detergent that works on multiple surfaces, this KÄRCHER concentrate is an excellent choice. Its high dilution ratio and broad compatibility make it a standout value, and the overwhelmingly positive reviews back up its effectiveness. For the price, it’s one of the best all-purpose pressure washer soaps available.

5

Simple Green Oxy Solve Total Outdoor Cleaner

SimpleGreen
9.6 /10
YPS Score
YPS score rating is a scoring system developed by our experts. The score is from 0 to 10 based on the data collected by the YPS tool. This score doesn't impact from any manufacturer or sales agent websites. Learn more ›
Simple Green Oxy Solve Total Outdoor Cleaner is a peroxide-based concentrate that effectively removes dirt, grime, and stains from multiple outdoor surfaces. Its EPA Safer Choice certification and pet-safe formula make it ideal for environmentally conscious homeowners seeking high-performance cleaning.
Pros & Cons

Pros

  • High concentrate yield covers large areas economically.
  • Safe for environment and pets, non-toxic peroxide formula.
  • Versatile on multiple surfaces (wood, concrete, vinyl, brick).
  • Fast and effective stain removal with minimal effort.
  • Positive customer feedback on ease of use and results.

Cons

  • Requires thorough rinsing to avoid residue on vertical surfaces.
  • May not remove extremely old or set-in stains on porous surfaces without extra scrubbing.
  • Some users report needing a pressure washer for best results on tough grime.
Detailed Review

The Simple Green Oxy Solve Total Outdoor Cleaner is a concentrated, peroxide-based formula designed for homeowners who want to clean outdoor surfaces without harsh chemicals. It is ideal for use on wood decks, concrete driveways, vinyl siding, brick patios, and composite materials, making it a versatile addition to any cleaning arsenal.

Standout features include its ability to cover up to 6,400 square feet per gallon when diluted, offering exceptional value. User reviews consistently praise its fast-acting foam that lifts dirt, algae, and mildew within minutes, often requiring just one application. The peroxide formula is strong enough to remove tire marks and stubborn stains yet safe for pets and plants once rinsed.

The product comes in a sturdy 1-gallon jug with clear dilution instructions. The concentrate is easy to mix and can be used with a pressure washer or manually with a brush and bucket. The EPA Safer Choice certification adds credibility for eco-conscious buyers.

One drawback is that the cleaner must be rinsed thoroughly to prevent white residue on vertical surfaces. Additionally, heavily embedded stains may need extra dwell time or scrubbing. Some users find that a pressure washer significantly enhances results compared to manual application.

Overall, this outdoor cleaner delivers on its promises with high efficiency and environmental safety. It is a strong recommendation for anyone seeking a reliable, versatile, and eco-friendly solution for restoring outdoor surfaces.

Specifications

Product Dimensions: 7.68 x 4.7 x 11 inches

Item Weight: 9.27 pounds

Model Number: 8541813566

ASIN: B07DV21X32

Best Sellers Rank: #71 in All-Purpose Household Cleaners

6

Simple Green Oxy Solve House and Siding Pressure

SimpleGreen
9.5 /10
YPS Score
YPS score rating is a scoring system developed by our experts. The score is from 0 to 10 based on the data collected by the YPS tool. This score doesn't impact from any manufacturer or sales agent websites. Learn more ›
Simple Green Oxy Solve House and Siding Cleaner is a powerful, concentrated formula that eradicates mold, mildew, and tough stains on exterior surfaces like vinyl, wood, and brick. Ideal for homeowners using a pressure washer to restore their home's curb appeal with minimal effort.
Pros & Cons

Pros

  • Highly effective at removing stubborn mold and mildew stains.
  • Versatile for many exterior surfaces including siding, decks, and fences.
  • Concentrated formula means a little goes a long way.
  • Safe for plants and pets when used as directed.
  • Rinses clean without leaving residue.

Cons

  • May require multiple applications on heavily soiled or old stains.
  • Not suitable for use on unsealed or porous surfaces that may absorb the cleaner.
  • Some users may find the scent strong during application.
Detailed Review

The Simple Green Oxy Solve House and Siding Pressure Washer Cleaner is a specialized exterior cleaner designed for homeowners who want to remove unsightly mold, mildew, and stains from their home's exterior. It's particularly effective on vinyl siding, aluminum, wood, brick, and stucco, making it a versatile addition to any pressure washing arsenal.

What sets this cleaner apart is its oxygenated formula that actively lifts organic stains rather than just bleaching them. In real-world use, it performs exceptionally well on shaded areas where mold and mildew thrive, often restoring surfaces to their original brightness with a single pass when used with a pressure washer. Users report noticeable results on decks, fences, and siding.

The product comes as a 1-gallon concentrate, which can be diluted according to the included instructions for different cleaning tasks. This makes it economical, as one gallon can cover a substantial area. The formula is also biodegradable and safe for plants when used as directed, which is a significant advantage for environmentally conscious homeowners.

One minor drawback is that heavily stained surfaces might require a second application or a longer dwell time before rinsing. Additionally, the scent, while not overpowering, is noticeable during use. However, these are minor trade-offs for the cleaning power this product delivers.

Overall, the Simple Green Oxy Solve House and Siding Cleaner is a reliable and effective solution for exterior cleaning projects. Its ease of use, versatility, and strong stain-lifting ability make it a top choice for anyone looking to boost their home's curb appeal without harsh chemicals. Whether you're a seasoned pressure washer or a first-time user, this cleaner is a solid investment.

Specifications

Product Dimensions: 7.68 x 4.7 x 11 inches; Weight: 9.27 pounds

Item Model Number: 8541813567

Date First Available: June 19, 2018

Manufacturer: Sunshine Makers, Inc

ASIN: B07DVVJQCG

Best Sellers Rank: #1,547 in Industrial & Scientific, #13 in Commercial All-Purpose Cleaners

7

Krud Kutter Multi-Purpose Pressure Washer

Krud Kutter
9.5 /10
YPS Score
YPS score rating is a scoring system developed by our experts. The score is from 0 to 10 based on the data collected by the YPS tool. This score doesn't impact from any manufacturer or sales agent websites. Learn more ›
This Krud Kutter concentrate is a powerful, bleach-free outdoor cleaner that tackles tough stains like oil, grease, and tree sap on a wide range of surfaces. Ideal for homeowners and professionals needing an efficient, no-scrub solution for large pressure washing projects.
Pros & Cons

Pros

  • Highly concentrated, excellent value for large projects
  • Works on a wide variety of surfaces without damage
  • No scrubbing required, saves time and effort
  • Bleach-free and biodegradable, environmentally friendlier
  • Protects pressure washer from corrosion

Cons

  • May require multiple applications for heavily stained surfaces
  • Not suitable for use on all delicate materials, test on inconspicuous area first
  • Some users may prefer a scented formula
Detailed Review

The Krud Kutter Multi-Purpose Pressure Washer Concentrate is a versatile and powerful outdoor cleaner designed for both residential and commercial use. It is ideal for homeowners who want to restore the appearance of their siding, decks, driveways, and patios, as well as for professionals who need a reliable solution for large cleaning jobs.

This concentrate stands out for its ability to penetrate and remove tough stains like oil, grease, bird droppings, and tree sap without the need for scrubbing. Simply apply with a pressure washer, allow it to dwell for 3-5 minutes, and rinse. The formula is bleach-free and biodegradable, making it a safer choice around plants and pets.

In terms of performance, one gallon makes up to 20 gallons of cleaning solution, covering up to 5,800 square feet. This makes it exceptionally cost-effective for big projects. The product also contains anti-corrosive agents that help protect your pressure washer, extending its lifespan.

While the cleaner is highly effective, heavily stained surfaces might require a second application. Also, as with any cleaner, it's wise to test on a small, inconspicuous area first to ensure compatibility with delicate materials. Some users might find the lack of fragrance a minor drawback, but it's a trade-off for the low-chemical formula.

Overall, the Krud Kutter Multi-Purpose Pressure Washer Concentrate delivers excellent value and performance. It simplifies outdoor cleaning tasks, saves time, and produces impressive results. Whether you're washing your home's exterior, a deck, or a vehicle, this product is a dependable choice.

Specifications

Brand: Krud Kutter

Model Number: 385462

Item Weight: 8.5 pounds

Volume: 1 gallon (128 fluid ounces)

Color: Purple

Coverage: Up to 5,800 square feet per gallon

Dilution: Makes up to 20 gallons of solution

Formula: Bleach-free, biodegradable, water-based with anti-corrosive agents

Manufacturer: Rust-Oleum

Buying Guide

Surface Compatibility

Not every cleaner works on every surface. Some formulas are designed specifically for concrete and brick, while others are safe for wood, vinyl, or stucco. Check the label to confirm your cleaner is compatible with the material you are cleaning. For instance, the Simple Green Oxy Solve Total Outdoor Cleaner is EPA Safer Choice Certified and works on wood, concrete, and vinyl without causing damage.

Concentration and Dilution

Concentrated formulas give you more cleaning power per gallon. They also reduce storage space and plastic waste. Look for products that specify how many gallons of ready-to-use solution they make. The KÄRCHER Multi Purpose Pressure Washer Detergent is highly concentrated, making up to 20 gallons of usable cleaner.

Stain Removal Power

Different stains require different active ingredients. For mold, mildew, and algae, oxygen-based cleaners like those from SimpleGreen are effective and bleach-free. For oil and grease on driveways, a heavy-duty degreaser like the Simple Green Pro HD Heavy Duty Cleaner Concentrate is ideal. Always rinse thoroughly after application.

For more on maintaining a clean home environment, explore our Pressure Washers category.

Final Thoughts

Choosing the right cleaning product for your pressure washer depends on the surfaces you need to clean and the type of stains you face. For a versatile, all-in-one solution that works on siding, driveways, and wood, the Simple Green Oxy Solve Total Outdoor Cleaner is a top choice, while for heavy-duty degreasing on concrete and equipment, the Simple Green Pro HD Heavy Duty Cleaner Concentrate delivers professional-grade results. Both products are backed by thousands of user ratings and offer reliable performance for your outdoor cleaning projects.

Frequently Asked Questions

Can I use dish soap in my pressure washer?

Dish soap is not formulated for pressure washers and can create excessive foam, damaging your machine’s seals. Always use a cleaner specifically designed for pressure washers.

What is the best cleaner for mold and mildew on siding?

Oxygen-based cleaners like the Simple Green Oxy Solve Total Outdoor Cleaner are excellent for mold and mildew. They are bleach-free and safe for most siding materials.

How much cleaner do I need for a typical driveway?

For a two-car driveway (about 400 square feet), you will need roughly 1 to 2 gallons of diluted solution. Follow the dilution ratios on the product label, and always check a small area first.

Are pressure washer cleaners safe for plants and pets?

Many cleaners are biodegradable and safe once dry. However, you should always rinse plants with water after cleaning and keep pets away until the surface is dry. For more tips on keeping your home clean and safe, read our guide on best 16x25x5 air filters.