Soft Wash vs. High Pressure Washing; Industry Best Practices Revealed!

One of the most important considerations for homeowners hiring power washing contractors to wash the exterior of their home is: what kind of washing service will I get? This seems straight-forward question… of course I’ll know what the power washer is going to do on my property’, most homeowners think. But the reality is, power washing the right way is more complex than many homeowners think. It’s one of the bigger debates in the entire exterior cleaning industry!

Soft Wash vs. High Pressure Washing

Soft wash vs. high pressure washing for residential homes. Which is better? Which should you have your local powerwashing company perform on your house? Does the best method depend on whats being washed, or are there other considerations that are more important?

Before we can decide whether soft washing or high pressure washing your house is a better method, we first need to understand how each one works when the water hits your house.

Contents

What is high pressure washing?

What pops into your mind when you think “pressure washing” or “power washing”?

Chances are, you’re visualizing a high pressure washer; which can be defined as a water tank, powered by a motor and pump, that shoots water at a (generally dirty) target through a series of hoses. These hoses are connected to a wand that’s controlled by the user.

According to the United States Patent and Trademark Office, the machine’s official name is the high pressure cleaning apparatus. Here are images submitted with the patent:

Pressure Washer Patent Image 1

Pressure Washer Patent Image 2

Photo credit and summary via Google Patents. Click for more full information.

Who invented the high pressure cleaning apparatus?

According to the USPTO, the power washing machine, or high pressure cleaning apparatus, was most recently patented in the late 1990’s. It’s date of invention however, is shrouded in a bit of controversy…

German manufacturer Alfred Kärcher GmbH & Co. KG claims invention in 1950, with the DS 350 model. American Frank W. Ofeldt II on the other hand, claims he invented the original high pressure washer, then called the Hypressure Jenny, in Philadelphia during 1927 (Source).

Most sources agree that Karcher (pictured below using an original model of the machine) was the official inventor.

Alfred Karcher; Inventor of the Pressure Washer

Technical Definition

According to the patent mentioned above, a high pressure washer is:

Comprising an electric motor arranged in a housing, a high-pressure pump arranged in a housing, at least one piston entering a pump chamber in a sealed manner, and a swash plate carried by the motor shaft of the electric motor, with the piston or pistons of the high-pressure pump resting in a resilient manner against the swash plate, the transition from the motor shaft via the swash plate to the piston or pistons being electrically interrupted by an electrically insulating material interposed there between.

High-Pressure Cleaning Apparatus; US Patent #5,886,436

Now that we understand what a high pressure washer is, it’s time to consider the pros and cons of using such a device to clean your house, roof, or personal property.

Benefits of high pressure washing

Washing with a high-pressure cleaner is beneficial when there’s thick dirt and grime build-up on a the surface that needs removal. For example, a popular use for high pressure washing machines is with graffiti removal.

Even when graffiti paint seeps into concrete and sits over the course of years and years, pressure washing it away is possible because of the science behind how a pressure washer works…

Kinetic energy!

Kinetic energy makes high-pressure washers effective

Kintetic energy is energy in motion, and that’s exactly what’s happening when water shoots out of a pressure washing machine at it’s dirty target. Think of each tiny water molecule as a tiny hammer hitting the surface of what’s being washed. The pressurized energy beats away at whatever’s on the surface, generally resulting in a ‘like new’ shine!

Unfortunately however, this cleaning method isn’t all puppies and ponies because the exact pressure that’s responsible for the effective cleaning can also be the culprit for damage. This happens most when pressure cleaners aren’t used on the right surfaces or if the correct settings aren’t chosen on the machine.

Downsides of high pressure washer use

The claim to fame of pressure washers can also be their downfall…

Water shooting out of the wand knows no bounds, so if you’re not careful (paying attention!) then you can start to deteriorate the integrity of even the toughest surfaces. This is why power washing machines have extensive warning labels!

This big downside to pressure washers is why many homeowners are scared to rent one to clean their home; and instead opt for a professional power washing company to help do the dirty work.

Can it really be so bad, though?

Yes. I’ll spare you of the graphic images of roofs ruined by pressure washers. They’re too graphic! Here’s a picture of a deck that got significantly mangled by pressure set to high on a machine:

Deck ruined by high pressure washer setting

Downside of high pressure washing your roof

If you’re from Massachusetts like us or have ever visited, then you’ve likely seen many roofs that look like this:

Black streaking on roof

or perhaps a roof like this…

Moss on roof before cleaning

These examples moss growth and black streaking are more common in Massachusetts and New England than other parts of the country because of the repeating cycle of precipitation, humidity, freezing, thawing, heat again, then back to cold! Needless to say, this does a number on the deterioration of asphalt shingles.

So how do you fix it without breaking the bank?

Instead of buying a new roof, many homeowners concerned about curb appeal will instead opt to pressure wash the algae or black streaking off their roof because they’ve heard it works...

And sure, it does work, but it’s a dangerous proposition for the integrity of your roof!

Why asphalt breaks down under high pressure

Modern roofing shingles are comprised of layers upon layers of tiny asphalt granuals. Little bits of asphalt are pushed together (sometimes with a light adhesive) and a shingle is born…

But anyone who’s ever cleaned their gutters can agree with me when I say that this asphalt breaks apart quite easily. And that’s before hitting it with a pressure cleaner!

When you use high-pressure from the power washing machine on your roof, you’ll succeed in eliminating the moss and algae, sure. But lots of asphalt granuals from your shingles will also go with it. This is why when you power wash your roof, the same problems often come back in spades (sometimes only a year later). On top of this, the lost granuals aren’t replaced by anything. So structurally, the roof is now less strong. All because power washing best practices weren’t followed:

Ruined asphalt roofing shingles

Because of these reasons and more, we strongly suggest NOT using high pressure to wash your roof. The damage done by using pressure on your roof is irreversible. More moisture will seep into your shingles, which will have severely adverse effects to the health of your home.

Downside of high pressure washing your vinyl siding

Using a high pressure washer on vinyl siding is not advised by industry experts for a number or reasons:

First, if too high of a setting is selected on the machine and the vinyl siding is older, then all the pressure can start to break down the vinyl.

A good test to check whether your vinyl siding is starting to break down is to rub your hand over it. Is your hand chalky? Did any residue from the vinyl end up on your hand? If so, that’s oxidation:

Chalky Siding Oxidation

(Siding Oxidation Photo Credit)

Chalkiness means your siding is starting to deteriorate. In most cases, we recommend against using higher pressure on siding, but in this case we strongly advise against it.

But what will you use to clean the dirt, algae and grime off your home?

Consider the soft wash method…

The Soft Wash Method For Safe Power Washing

As discussed above, the benefits of washing anything with a high pressure method are clear. It works! But sometimes it works too well. So what’s a homeowner to do?!

How can you possible wash your home if high pressure methods have the potential to damage it? The answer, for many scenarios, is soft wash!

What is soft wash?

Soft wash is a popular power washing best practice used to clean delicate surfaces that would otherwise be damaged with higher-pressure methods. Pressure coming out of the hose is generally under 500 PSI, meaning you don’t even have to worry about sticking your hand in front of the stream. Here, I’ll prove it:

via GIPHY

Soft wash is commonly used to clean asphalt roofing shingles, vinyl siding, and stucco surfaces but can really be used to clean anything with grime caked on the surface.

How soft wash works

The soft wash method uses detergents and solutions to break down caked on dirt and grime on a surface. Instead of forcing pressurized water at the surface (as is the case with high pressure washing), the detergents and solutions settle and slowly eat away at the grime. This makes soft wash a safer alternative, especially for residential properties.

Step #1

The first step to the soft wash method is spraying a mixture of power washing solutions on to the surface you’re cleaning. Pro tip: Don’t be afraid to let the solution sneak into all the nooks and crannies because it’ll break down all the dirt in there too!

Step #2

Let the solution sit on the surface for 15-20 minutes. This is called dwell time. Exactly how long depends how dirty the surface is. If more dirt, algae, or grime needs to be removed, then allow the solution to sit longer. As the solution sits, it break down the dirt particles.

Step #3

After you’ve let the solution sit for 15-20 minutes, grab your wand and use a stream of ultra-low-pressure water to wash away the solution. Not only will the solution wash away, but the dirt will fly off with it too!

Benefits of soft washing your vinyl siding or roof

The main benefit of the soft wash is how delicate it is. Unlike high pressure washing, you won’t need to worry about chipping paint or shooting asphalt off your roofing shingles because there won’t be enough water pressure to do so.

Avoiding damage to your property is a huge benefit to soft wash, but it’s not the only positive…

Soft wash has scientific benefits that go beyond just the of cleaning your siding or roof. When detergents and/or solutions sprayed onto the surface in step #1 (mentioned above), they break down the mildew and algae. This we know. But consider what else is being removed behind the scenes: bacteria! As the grime flys off your house, so goes with it much of the bacteria. This makes soft washing beneficial beyond just boosting curb appeal. Your house becomes healthier because of it!

You may be wondering, doesn’t using a high-pressure washing method also remove the algae or mildew from a dirty surface? Wouldn’t the bacteria go with it too?

And yes, you’d be correct. Using high-pressure does remove mildew and other grime from the surface, but high pressure isn’t enough to remove the spores themselves. Using high pressure will result in a less clean surface, plus the need to wash it again in only a year’s time!

Soft was sounds great, right? What’s the catch?

Are there downsides to soft washing?

Downsides to soft washing do exist, but fortunately they’re minimal in comparison to the downsides of using a high-pressure method to wash your home or roof.

Soft washing is more complex than using high pressure methods

Though it’s not the most complex home improvement project to pull off, soft washing is more complicated than just pointing and spraying a pressure washer at a dirty surface to clean it. Because of this, it’s important to do your homework before adding soft wash as a service for your power washing business and especially before you try to tackle soft wash as a DIY home improvement project.

Soft wash chemicals can damage plants

Some power washing professionals have noted that using a soft was method isn’t advised for home with lots of plant life lining the house’s exterior. However, this has been a contention point amongst many power washing professionals. Many experienced pro’s have come forward debunk the dangers of power washing solutions ruining plant life:

I have been pressure washing for a living here in Souhtwest Florida since 1989. Anyone who has ever pressure washed a shingled roof has to admit- at ANY pressure setting that will clean shingles, there is considerable granule loss. After a few years of blowing granules off of roofs, I learned to soft-wash them and have done so, starting in 1991 and have never run into any damage caused using this method. That is IF YOU PROTECT THE PLANTS BELOW. After thousands of roof cleanings, with the utmost plant care, I have killed 5 plants total and I replaced them.

Florida Powerwashing Professional on CleaningTalk.com's Forum

Ending the soft wash vs. high pressure washing debate

So, what’s the verdict? Who wins the battle between classic, time-tested high pressure washing methods and the newer, arguably safer and more delicate soft wash? Since both have their advantages and disadvantages when it comes to effectively cleaning dirt-ridden surfaces, how can we possibly choose a winner?

At Now Powerwash, we believe in a holistic approach to exterior cleaning. Whether you should use soft wash or high pressure washing techniques on your next exterior cleaning project really boils down to what you’re washing.

Should I Pressure Wash or Softwash my roof?

Because of the high likelihood of shingle damage that can be caused by using high pressure directly on asphalt, we urge you to use the soft wash method for roof cleaning in place any higher pressure method. You certainly don’t want to watch asphalt fly straight off your roof because that means you’re also watching integrity of your shingles become compromised.

Roofing is delicate enough, so it’s unnecessary to run the risk of further damaging one of your home’s most important assets (your roof) with a pressure washer.

Should I pressure wash or soft wash my vinyl siding?

Similar to the reasons stated in our recommendation for using soft wash over high pressure in roof cleaning, we recommend you use the soft wash method to clean your home’s vinyl siding for the same reasons. On top of mitigating damage risks, it’s simply more effective and better for the environment.

Soft wash will save you money

Since soft wash fully breaks down bacterial particles that help mildew cling to your siding, the fresh curb appeal will stay for much longer…

If your home stays clean longer, you’ll have to wash it less…

…and if it needs less washing, that’s less money our of your pocket. Money you can spend to have a professional power washing contractor wash your fence or clean your walk way. Or perhaps extra cash to spend on any other home improvement project you’ve been meaning to check off your list!

Exceptions

Small exceptions to soft washing your siding do exist, and I’d be remiss not to mention them…

At times, extra dirt or moss builds up on one section of your siding and if it’s been there for a number of years, it can really get caked on. If this is the case and it’s out of arm’s reach (or in a dangerous position to access via ladder), then it’s okay to use a pressure washer to get part of it off before starting step #1 of the soft wash method.

If you do this, take extreme care and make sure to use the lowest PSI setting on the power washing machine that will remove the clumps of dirt. Start low, then raise the pressure until there’s enough strength for it to fall off.

Should I pressure wash or soft wash concrete/stone?

Now here’s where we recommend using a higher-pressure wash for cleaning!

Because surfaces like pool decks, walkways, and driveways are resilient, it’s best to use a high pressure washer if you don’t have access to a surface cleaner. Surfaces like retainer walls are the perfect opportunity to use a high pressure method. Check out this video of me cleaning a retainer wall in Rowley, Massachusetts using this method.

Bonus: Should I pressure wash or softwash my car?

If you’ve read this article from the beginning, you’ll agree with me when I say that you definitely should not take a pressure washer to your car at full blast, no matter how much sap has built up! The pressure can not only significantly damage your car’s paint job, but it can also chip away at already-rusted areas. Many modern cars and trucks have thinner pieces of plastic used for aesthetics which can easily shatter under high pressure.

Pressure Washing Cars

(Photo Credit & Mini Car Power Washing Article)

Can I really powerwash my car?

Your short answer is yes, you can use a power washer to clean your car, but be careful of the settings used on the machine as well as the solutions you choose…

Interestingly, eBay of all places has a mini-guide for power washing your car.

Disclaimer

When power washing your car, always use soft wash or a very very low setting on your pressure washer. In addition, we recommend you adhere to all manufacturer guidelines. And I mean both the manufacturer of the solution you choose, as well as your car’s manual. When in doubt, give the car company a call to clarify whether or not a particular solution will be harmful to the paint on your car.

Now that we fully understand the pros and cons of the soft wash vs. high-pressure washing debate, let’s dive into particular equipment and solutions used in the process.

What soft wash equipment will I need to clean my house?

Differences in washing techniques make it necessary for you to have different equipment for soft washing than what’s used for more traditional pressure washing techniques. Because of the wide variety of power washing equipment options, we’ll focus on just a few key items that are undoubtedly needed for performing soft wash services.

Soft Wash Equipment Recommendations

Disclaimer: complex purchases like power washing setups and equipment should be made only after doing due diligence and reading through reviews from multiple trusted resources. The recommendations below should be used simply as a guide for your soft wash setup purchases.

Soft Wash Kits And Systems Can Save You Money

Power washing setups can get confusing when you’re new to the industry. The machines are complex, not to mention all the small parts needed to guarantee the whole setup works together. Piecing one part from one manufacturer with another part from a different manufacturer leaves lots of room for error.

Because of this confusion felt by most industry-newcomers, many power washing stores offer soft wash kits for purchase online. These kits are meant to be a ‘one-stop-shop’ for everything you’ll need to get started with your soft wash business and by buying as a package deal, you’ll save money when compared to buying individual parts.

You’ll also save yourself time and headaches that come with piecing together soft wash equipment when you’re not an industry veteran.

Below are a few soft wash kit recommendations:

Top Kit: Delux® Stallion Gas Powered Soft Wash System

Here’s a video explanation of the highly-reviewed Delux® Stallion Gas Powered Soft Wash System

The system sells for $3,339.00 and is billed by the manufacturer as extremely quiet, which is a benefit for residential power washing jobs that start early in the morning. Don’t wake the neighbors! In addition, the Delux Stallion promises to be a certified by both the Environmental Protection Agency and California Air Resources Board.

A powerful Honda GX 200 engine powers the machine:

Honda GX200 Engine

A few more important features included with the Stallion power washing system:

  • Titan 304 stainless steel hose reel
  • 150-foot 5/8 inch industrial grade PVC hose
  • 24 inch PVC wand which comfortably attaches to the hose
  • JA-8000 chemical-resistant trigger gun (trigger lock included, which makes spraying for long periods easier)
  • A J-Rod quick-connect nozzle holder with three steel nozzle included (20* size, 40* size, and 60* size)
  • #5 Assassin 2™ PVDF Nozzle (allows solutions to be shot up to two stories in height)
Soft Wash Pump Kits

If you already have a machine that can be used for soft washing and only need other soft-wash friendly equipment like hoses and nozzles, then you can get by with one of the lower-priced kits that doesn’t include any expensive machinery.

For these needs, many shops offer ‘pump’ kits that come with, you guessed it- a pump! Plus all the parts and supplies needed to make your machine soft wash friendly.

Powerwash.com is a great resource if you’re looking to purchase one of these kits. They have a handful of different options available and each option takes what you already own into consideration, meaning some kits come with pumps while others do not. Here are two examples:

Soft Wash 7150 Pump Kit With Accumulator Tank

Powerwash.com’s 7150 kit includes an accumulator tank. This kit is a good option if you already have a machine, but don’t own an accumulator tank because you’ll need an accumulator tank in order to properly execute the soft wash method:

accumulator-tank

Accumulator tanks allow you to adjust the flow of water leaving your wand. If you’re soft washing professionally or even for homeowners with large homes, it’s important to be able to raise and lower pressure coming from your machine as needed. Matching water flow with the needs of each property is part of the art of power washing!

Also included:

  • Four PVC Hose Barbs
  • Three Hose Reel Clamps
  • One Soft Wash Gun
  • One Soft Wash Wand
  • One Stainless Steel Quick Coupler Male Socket
  • Four Stainless Steel Quick Coupler Female Plugs
  • Four V-Jet Nozzles
  • 162 Ft. of Poly Braid Clear Vinyl Tubing
  • 16 oz Fresh Wash Sample (a bonus!)
  • One Mesh Filter Screen
  • PTFE Thread Seal Tape

Through Powerwash.com’s website, this kit costs $799.00.

Soft Wash 5360 Pump Kit

In place of the accumulator tank that comes with soft wash kit 7150, this kit includes a Delux D5360 power washing pump. In total, the 5360 soft wash kit will run you $499.00 and includes many of the ‘extras’ listed in the kit above.

For full detail on this soft washing kit and to check out other options, head over to Powerwash.com. If you’re in the market for any soft wash supplies then I suggest browsing their website so you can see which kits fit into your budget.

Soft Washing Machines

When searching for soft washing machines, you’ll find many come with titanium hose reels. Also note that many of these machines are billed as roof cleaning machines. This confused me a bit when I entered the industry, so I feel it’s worth mentioning here:

These “roof cleaning machines” are the same machines used to soft wash just about anything. They’re soft wash machines! But they’re marketed as roof cleaning machines because cleaning roofs is their most common use.

Entry Level: Mustang Soft Wash Machine

On a budget?

The Mustang machine is an entry-level option if you’re looking to save a few bucks on your power washer. Downside is that it’s battery operated, so keep extra batteries on hand if you have a big job to complete. It comes with a charger though, which will save you a bit of money if you’re washing lots of homes.

The Mustang is a good machine for newcomers to the industry or homeowners looking to have a professional-style washer on hand for cleaning big properties. Reviews state that it has the power to shoot 30+ feet, which is a good distance for most small-medium sized residential homes. It’s priced at $949.00 Learn More Here.

Premium: PressureTek’s Fat Boy Bandit Roof Cleaning System

PressureTek is a highly-regarded brand in the professional power washing community. Many contractor’s businesses are powered by PressureTek’s FatBoy Bandit machine.

pressure-tek-fatboy-bandit-roof-cleaning-system

(Fat Boy Bandit Photo Credit & Purchase Details)

Billed as a system, it’s not the type of kit we covered above but does come out of the box with more than just the machine itself. Included with your purchase of a bandit is an aluminum hose reel and 4-nozzle holder. The premium machine is listed for $1,414.00, which PressureTek claims can be shipped to your door in only 1-2 weeks.

As an added bonus for those starting their own pressure washing business, PressureTek offers financing options and states this machine can be financed for as low as $39 per month. No doubt a route to consider if you’re tight on funds when starting out in the industry.

Soft Wash Nozzles

We won’t get too deep into any more soft wash equipment, but I can’t leave out nozzles because they’re a critical piece of equipment needed for effectively executing the soft wash method.

Power Washing Nozzle In Action

What do power washing nozzles do?

Using the correct nozzle is critical for any power washing job because it allows you to adjust the water pressure leaving your wand. Without any nozzle at all, the water would simply drip out of the hose. Picture a garden hose without a nozzle or tip attached. That’s what would happen with your pressure washer.

With garden hoses, you can place your thumb over part of the opening and water will shoot out faster and further. The same mechanics hold true for the nozzles you’ll connect to the end of your power washing hoses, so as you can imagine, they’re very important when it comes to soft washing roofs, vinyl siding, and anything delicate. You want to be able to adjust your pressure on the fly.

Choosing Nozzles for Soft Washing

I’ll cover nozzles in greater detail in another post, but here’s an informative chart created by the Powerwash.com. All power washing contractors highly recommend you use as low a pressure as possible when soft washing so you limit damages that can occur due to high pressure.

Click here for sizing chart

All this talk of machines used for soft washing and why choosing the correct nozzle is important for success and you may be wondering what detergents and solutions will be needed for power washing the soft wash way.

Which detergents and soaps are used to soft wash houses?

A main benefit of soft washing vs. high pressure washing is that you’re able to more easily break down mildew, dirt, and grease. Doing so is possible because soft washing uses chemical-based solutions where high-pressure washers generally do not.

Soft wash detergents help break down the dirt on a molecular-level which leaves your surface clean for much longer than if you used any traditional high-pressure washing method. Many brands exist, each with different strength grades.

Our pick: Simple Cherry Multi-Purpose Mild Cleaner

Simple Cherry Power Washing Solution

PressureTek’s ‘Simple Cherry’ multi-purpose mild cleaner is one of the main soft wash solutions we use here at Now Powerwash. We use it because just like the name says, it’s a mild option that’s generally safe for plant life.

And in case you were wondering, the solution does smell like fresh cherries!

We’ll cover the best solutions for power washing in another article, but worth noting here is Simple Cherry’s softening agents. These proprietary chemical compounds make rinsing the solution from your home’s vinyl siding easier and safer. While other (harsher) soft wash solutions can damage glass or paint, Simple Cherry is safe to touch those surfaces. It’s safe on wood too!

Safety and taking care of your home’s exterior should be the primary concern of any power washing professional that comes to your property for an estimate. Always choose a power washing company who’s able to demonstrate proper industry knowledge.

While power washing seems simple at a glance, you can see from the information in this article that its complexity can’t be understated. And when it comes to choosing whether to soft wash or high-pressure wash your home, always air on the side of caution before cranking that nozzle of yours to the max!

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Soft Wash vs. High Pressure Washing; Industry Best Practices Revealed!
Article Name
Soft Wash vs. High Pressure Washing; Industry Best Practices Revealed!
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Ending the soft wash vs. high pressure washing debate. Detailed explanation of each method, including pros and cons. Plus, recommendations for soft wash equipment and solutions.
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Now Powerwash
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About the Author Nathan Owens

Massachusetts native Nathan Owens founded Now Powerwash in 2010. He's a proud father, United States Army veteran, and registered nurse. When he's not hard at work for Now Powerwash, you can find him saving lives in the Anna Jacques Hospital emergency room in Newburyport, MA.

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1 comment
Tammie Houston says October 31, 2017

We are planning to get everything cleaned for the holidays and that includes our vinyl siding. If it wasn’t for your article, we could’ve have done pressure washing and end up destroying our vinyl siding. It’s probably for the best to hire someone to help us with and determine which parts are better suited for soft washing. Thanks!

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