Soft Wash Pressure Washer Equipment

What is Soft Washing?

Soft washing is a cleaning process that combines low water pressure, high water volume, and specialized detergents to eliminate algae, mold, mildew, lichen, and other organic buildup from exterior surfaces. Rather than depending on the force of high-pressure water like traditional pressure washing, soft washing uses cleaning solutions to attack and remove contaminants at their source. The higher water volume helps evenly apply the solution and thoroughly rinse the surface afterward. This cleaning method is gentler on vulnerable surfaces, more effective on organic growth, and longer lasting.

The basic process consists of:

1. Applying the chemical solution.
2. Allowing it to dwell for 10-20 minutes to kill the organic growth.
3. Then rinsing with water to remove dirt and debris.

Benefits

• Gentler Cleaning - Since soft wash uses chemical solutions applied at low pressure, it won’t damage delicate surfaces that typical pressure washers would harm.
• Lasting Results - Soft wash chemicals break down organic growth by eliminating microbes preventing them from returning quickly.
• Less Water Consumption - Soft washing systems use significantly less water compared to traditional pressure washing.

What Does Soft Wash Remove?

Soft wash uses chemicals to remove dirt and grime as you would expect. But its claim to fame is the ability to attack organic matter at the molecular level ensuring it does grow back after being removed. This leads to results that last longer.

Soft Wash Removes

• Algae
• Mold
• Mildew
• Stubborn stains
• Insect carcasses
• Webs
• Nests
• Dirt
• Grime

Surfaces to Soft Wash

Soft wash systems utilize low-pressure streams of water to deliver cleaning solutions ensuring a gentle touch that will safely clean delicate surfaces that high-pressure streams from pressure washers would damage.

Delicate Surfaces Perfect for Soft Washing

• Roofs
  
• Siding
• Decks
  
• Stucco
• Awnings
• Gutters
• Windows
• Masonry
• Stonework
• Patios
• Pavers
• Wood
• Vinyl
  
• Driveways

Environmental Considerations When Soft Washing

When approached responsibly, soft washing can be done in an environmentally friendly manner. While SH can be harmful to plant life, humans, and animals, it also degrades relatively quickly from sunlight exposure and reactions to organic matter. Of course, highly concentrated SH mixtures pose more threat than more diluted ones. Additionally, the proximity of the area being treated to storm drains, bodies of water, and water reservoirs plays an important role as well. If there's a chance that residual SH solution may immediately enter these areas, the ethical approach is to divert, berm, vacuum, or otherwise responsibly dispose of the materials. For detailed information on the environmental impact of soft washing, take a look at this excellent resource from the National Softwash Authority to learn more.

What is a Soft Wash System?

Soft wash systems are similar to standard pressure washers, only they're designed for lower pressure levels, chemical resistance, and high volume. In a basic sense, a soft wash system usually consists of an efficient gas or electric motor and a chemically resistant pump (usually diaphragm) with a maximum working pressure usually coming in around 300 PSI. The pump itself, along with the fittings, regulators, unloaders, and other components used with it are all made of materials that can handle the chemicals commonly used for soft washing. The motor and pump are typically mounted on a metal frame or cart, creating a convenient, compact unit that's ready for soft washing jobs! Our systems are lightweight, weighing less than 100 pounds, allowing them to be easily transportable or quickly mounted on a truck.

Selecting a Soft Wash System

When selecting a soft wash system, the two most important specifications to consider are flow rate and pressure. You want to pick one with a maximum pressure between 300 and 500 PSI. This is the optimal pressure range for soft wash applications. Higher flow rates are recommended to help the unit project cleaning solutions and water higher. A good middle ground is 8-11 GPM that allows you to reach 20-30 feet. Check out our blog about selecting a replacement pump, which includes information about the impact of flow rate on the range of a soft wash system. There are many other features to consider such as mobility, chemical resistance, and more.

Gas vs. Electric Power for Soft Wash Systems

Gas and electric soft wash systems each have clear strengths, so the right choice depends on how and where you work. Gas-powered units are often preferred for mobile commercial jobs because they do not need an external power source, and they can run all day in the field as long as you have gas on hand. They are a strong fit for contractors cleaning roofs, siding, and large exterior surfaces across multiple job sites. Electric soft wash systems require a power source like a battery or plug/cord. However, electric systems are quieter, produce no engine exhaust, and usually require less routine service. That makes them a practical option for indoor wash areas, fixed workstations, or operators who want simpler startup and maintenance. While gas models offer maximum portability, electric models can lower fuel costs and reduce noise in customer-facing environments. Since both system types can deliver the low PSI and high GPM needed for soft washing, buyers should compare power access, jobsite mobility, maintenance demands, and daily run time before choosing a unit.

Soft Wash System Maintenance Tips

Soft wash system maintenance is mainly about protecting the pump, hoses, valves, and fittings from chemical wear. Since sodium hypochlorite is hard on equipment, operators should flush the system with clean water after every job. This helps remove leftover chemical, and it reduces buildup inside the pump and lines. You should also inspect strainers, seals, and O-rings often, because small worn parts can cause leaks or poor draw. While checking the unit, look for cracked hose, loose clamps, and corrosion on metal parts. Diaphragm pumps need regular service based on run time, so follow the manufacturer schedule for oil changes, valve checks, and diaphragm replacement. Keep tanks clean, store the system out of direct weather when possible, and winterize it before freezing temperatures. Proper maintenance lowers downtime, extends equipment life, and helps your soft wash system stay reliable on commercial jobs.

Soft Wash Chemicals

Professional soft wash operations typically rely on sodium hypochlorite (bleach) to kill the source of organic matter such as mold, mildew, and algae. You can also use algaecides if you need to remove just algae. Surfactants are also helpful because they help the cleaning solutions stick to prevent chemicals from running down surfaces too soon. This also allows more time for them to work. There are also specialized cleaners that are formulated to clean specific surfaces. Some of these soft wash chemicals include house and siding cleaners that are safe for vinyl surfaces and products for decks and fences that are safe for wood.

Diluting Sodium Hypochlorite

Since sodium hypochlorite, also referred to as SH or bleach, is the most commonly used chemical for soft washing, it's important to understand how to dilute it for your needs. Here's the simple math:

• Take the desired batch size in gallons and divide it by the stock strength of the SH.
• Take that number and multiply it by the desired SH percentage you're aiming for.
• The resulting number is the gallons of SH you'll use for your mixture.

Example: Since a 50-gallon batch size, 12.5% SH stock strength, and 1% desired strength are common, we'll use those as an example:

• 50 ÷ 12.5 = 4
• 4 x 1 = 4
• Result: use 4 gallons of SH and fill the rest with water.

Here are some SH strength recommendations for different applications:

• Low Concentration (1-2% SH): Use this concentration for especially delicate surfaces where high strength may cause damage. Ideal for vinyl siding, painted surfaces, wood siding, windows, and frames.
• Medium Concentration (2-4% SH): Use this concentration for moderate organic material and stronger surfaces. Ideal for stucco, concrete, brick, masonry, gutters, and downspouts.
• High Concentration (3-6% SH): A high level of concentration may be necessary for very tough stains and high mold or algae presence. Ideal for asphalt shingle roofs, clay tile roofs, heavily soiled concrete, and areas with severe organic growth.

NEVER put these materials in a tank with SH:

• Strong acids like hydrochloric, sulfuric, and nitric
• Acid-based cleaners
• Acid compounds like aluminum chloride, ferric chloride, or alum
• Ammonia compounds like ammonium hydroxide, ammonium chloride, quaternary ammonium salts
• Organic materials like solvents, fuels, and alcohols
• Metals

Soft Wash Mixing Methods

Soft wash mixing methods vary by system design, job size, and the strength you need at the surface. The most common approach is batch mixing, where you combine water, sodium hypochlorite, and surfactant in a tank before you start spraying. This method is simple to manage, and it gives you a consistent mix from the first minute to the last. Proportioner systems work differently because they draw from separate tanks and blend water and chemical during application. They give operators more flexibility, especially when switching between lighter house washes and stronger roof mixes. Some contractors also use metering valves or blend manifolds to fine-tune ratios, while others rely on dedicated mix tanks for repeat jobs. However, no matter which method you use, accuracy matters since the wrong ratio can hurt cleaning results or damage surfaces. Label your tanks, measure carefully, and test your output at the gun so your soft wash system delivers the concentration you expect in the field.

Soft Wash Safety Tips

• Wear chemical-resistant gloves, eye protection, and boots any time you mix, transfer, or spray soft wash chemicals.
• Use a respirator when label directions or job conditions call for it, especially in tight areas with limited airflow.
• Pre-wet nearby plants, cover sensitive items when needed, and rinse landscaping before and after application to reduce chemical damage. You may even consider using neutralizers, such as sodium thiosulfate, that breaks down SH into harmless salts and water.
• Never mix chemicals unless the product label says it is safe, since improper mixing can create dangerous fumes.
• Check hoses, fittings, guns, and tanks for leaks before each job, and replace worn parts right away to avoid spills or equipment failure.
• Keep people, pets, and vehicles clear of the work area, and watch wind direction while you spray to limit overspray.
• Store chemicals in labeled, approved containers, and secure them upright during transport. Moreover, follow all product labels, local rules, and manufacturer guidelines for handling, dilution, cleanup, and disposal.

Related Categories

• Water and Chemical Storage Tanks
• Hose Reels
• Wands and Lances

Frequently Asked Questions

Is soft wash worth the money?

For professional pressure washers, there's no question that extra investment has to be made to incorporate soft washing into your repertoire. To get the best results, you'll have to purchase a dedicated soft wash system. Additionally, you'll need chemicals and accessories like hoses and guns to use with the unit. However, the investment pays off in the long run by avoiding damage to the surfaces your cleaning, effectively addressing tough organic soils that can't be removed with regular pressure washing, and expanding the types of jobs you can accept from clients.

What's the average cost to soft wash a house?

Professional operators generally charge an average of $300 to $500 per home for soft washing services. Of course, this varies significantly by region, business competition in the area, and size of the home being washed. A professional operator may charge about $.10 to $.12 per square foot on the low end, and $.50 to $.60 on the high end.

What is the best soft wash system?

We carry soft wash systems from BE Pressure and Comet because we consider them the most reliable options on the market. Both are highly reputable brands among pressure wash/soft wash professionals, and their systems are built to last with quality motors and pumps. For example, both BE and Comet use Honda GX200 motors that have an excellent power-to-weight ratio. For diaphragm pumps, BE uses their Centurion line, while Comet uses their P40 - both are well-regarded pumps in the industry.

How much does a soft wash system cost?

For a soft wash system that meets the demands of professional use, expect to pay at least $1,500. For example, the systems we offer range from about $1,600 to $2,000. Of course, it's important to note that this is only the cost for the system itself. When you're figuring out how much you'll have to spend, factor in that you'll need to add hoses, spray guns, chemicals, and other accessories to build your entire setup.

What are the best seal materials for soft washing?

When selecting equipment and accessories for soft washing, it's important to pay attention to the seal material used inside those items. This is particularly crucial when using sodium hypochlorite, as it can quickly degrade lower grade seals. The most popular and recommended seal materials for this application are FKM (Viton/Fluoroelastomer), PTFE (Teflon), and Kalrez. EPDM can sometimes be used with lower concentrations of sodium hypochlorite, but it's generally not the ideal choice. Nitrile (Buna-N) should be avoided altogether, as it will very quickly degrade, crack, and become brittle when used with sodium hypochlorite.

If you're using different chemicals than sodium hypochlorite, it's smart to always check the label and safety data sheet to help determine what seal material you should be using.

Can I use a pressure washer to soft wash?

No, you generally cannot do TRUE soft washing with standard pressure washers. The pumps on most pressure washers are not designed to have harsh soaps, bleach, and other chemicals run through them, as the metal components and seals inside will quickly corrode. So, it's not recommended to use a regular pressure washer for soft washing. You would have to replace your pump and any other parts that the chemical contacts with new chemically resistant components. Instead, the recommended option is to use a soft wash specific system with chemically resistant components already included.

However, you can install a downstream chemical injector that introduces chemicals AFTER water has already passed through the pump. The method we recommend is to use an X-Jet downstream chemical injector nozzle. This accessory is installed on the end of your wand and draws chemical directly from your bucket to mix with the water coming from your pressure washer when you pull the trigger on your spray gun. It uses metering tips inside to dilute to your preferred level. For a regular X-Jet, you'll have to place a wide-angle nozzle (typically 65 degrees or wider) on the end, while an X-Jet M5 has an adjustable nozzle at the end that can be twisted to change the spray angle from 0 to 60 degrees. You can also install a pressure washing chemical injector between the pump discharge outlet and hose, then use a wide-angle nozzle on your wand to achieve a soft wash spray for chemical application. The downside of these downstreaming methods is that you can't achieve the same strength concentrations you can with a dedicated soft wash system.

What's the best material for soft wash tanks?

The ideal material to choose for the tanks you use while soft washing is high-density polyethylene (HDPE). This material is resistant to SH and commonly recommended for storage. Opaque white HDPE tanks are the best way to go, as they reflect sunlight, keeping SH cooler while minimizing UV ray penetration. Black tanks block UV light but absorb heat, which can increase SH degradation. If you're using other chemicals, HDPE is typically still the best option, but always consult labels, SDS, and other data sheets and follow recommendations.