In this training, we will cover the basic Chemicals, Methods and Techniques used in the Exterior Cleaning Industry.

Understanding what we clean

What we clean


Before we attempt to clean, it is important for us to recognize what we are cleaning.

It is also important for us to know what on which surfaces, we are cleaning

It is also important for us to distinguished the differences between cleaning and restoration.

Here are some of the items that we clean or restore in the exterior cleaning industry.

Dirt Dust Cobwebs Gloeocapsa magma Mold Algae Lichen
  • Leaves 
  • Rust 
  • Oil 
  • Oxidation 
  • Mineral Deposits
  •  Hard Water 
  • Irrigation stains
  • Atmospheric Polution
  • Stains

Once we have decided what we are cleaning then we determine what surface that we are cleaning from.

Below are a few of the surfaces that are regularly Cleaned

  • Vinyl
  • Wood
  • Metal
  • Stucco
  • Glass
  • Fabric
  • Vehicles

  • Shingles
  • Plastic
  • Masonite
  • Composite 
  • Concrete
  • Paint

Once we have determined what we are trying to clean or restore off of what surfaces than we are able to decide what method and chemicals should be used.

What is Softwashing

Exterior Cleaning

To understand the use of the chemicals we first have to understand the applications in which they are to be used

The evolution of the exterior cleaning industry

In brief, the exterior cleaning industry methods have evolved from a hand and brush, to the development of a pressure washer with allowed the force to clean. With the higher pressure (psi) came the potential for damages on certain surfaces.

Then heat was introduced to the pressure washer and this enable the pressure washing system to be more effective especially against oils, gums, grease, ect.

But still when it came to most of the surface that were being cleaned the pressure was blasting off the dirt, molds, and algae, with hopefully little to no damages to the surfaces that were being cleaned.

Then the realization came that most of what was being cleaned was of a organic nature, the thinking was then introduced that can we clean more effectively if we seek to kill and eliminate the actual cause of the mold, mildew ect.

And thus the search for effective cleaning solution that could be applied to a surface and left to dwell and then rinsed, leaving the surface clean and the surface undamaged was searched for.

The Softwashing Concept

Softwashing is chemical cleaning designed to kill the mildew, fungus, algae and other contaminates growing on the exterior surfaces.

Softwashing technique is using the least amount of effective pressure to clean

Softwashing helps to kill organic stains and substances

Softwashing is using the mindset of applying chemicals and allowing them to do the cleaning vs using pressure to clean

Pressure Washing

There are however times when various levels of pressure are needed to clean.

High Pressure and the option of heat is still needed in most oil and grease cleaning, and also surfaces such as concrete.

Pressure Specific

In some circumstances there is a need for a specific amount of pressure to be used to ensure a surface is left clean.

Depending on the surface and the extend of the cleaning needed at times a blend of chemicals being applied and then washed with medium pressure is needed.

For example:

Lets say we are cleaning a porous retaining wall that is covered in algae, mold and even lichen. Simply applying a softwash solution will help kill the stains and the lichen ect. The surface will not be left looking fully cleaned. Rinsing with garden hose pressure will not make any difference either.

So there then becomes a need to find a pressure that is appropriate to the task. That will enable the surface to be left clean, but not to harm the surface in any way.

Sodium Hypochlorite

Sodium Hypochorite

Sodium Hypochlorite is the most popular cleaning chemical used in the exterior industry.

Sodium Hypochorite is a liquid

It is very effective, and affordable.

It can be purchased in strengths from 3%-13%.

It also can be purchased in bulk.

Sodium Hypochlorite

 is a chemical compound with the formula NaClO. It is composed of a sodium cation (Na+) and a hypochlorite anion (ClO−); it may also be viewed as the sodium salt of hypochlorous acid. When dissolved in water it is commonly known as bleach, liquid bleach, or liquid chlorine.[1] It is frequently used as a disinfectant or a bleaching agent.

These are all terms that are used to describe Sodium Hypochlorite:

Sodium Hypochlorite

  • Bleach
  • SH
  • Chlorine

Sodium = Salt

 Standard Percentages in which bleach can be purchased   3%-12% 

Bleach purchased at Wal Mart is typically 6%

SH purchased in bulk is normally 12%

Use 10% for your calculations

What Destroys Bleach?




Bleach goes dormant at 42 degrees 

Certain Metals

Calcium Hypochlorite

Calcium Hypochlorite is powdered bleach.

It can be used in the cleaning industry however these are the things to consider:

 Harder to mix

Because of the difficulty of the mixing and the ability to stay mixed is harder to calculate the exact percentage.

Calcium Hypochorite also has a tendency to leave a powdered film behind.

One of the benefits of CH is that because it is Calcium Hypochlorite instead of Sodium it does not damage the plants as easily.

Chemicals used in Softwashing

Softwash Solutions

When cleaning we develop a "custom cleaning solution" for every project.

Each project has its own cleaning needs.

Some might need a stronger percentage of SH than normal, while others have more non- organic staining, which could cause need for a non caustic de-greaser.

Others may have delicate surfaces or surroundings that need consideration.

Having a good understanding of the chemicals and there uses allows for you to develop an effective "custom cleaning solution" for the task at hand.

In this training we will refer to "organic" as living organisms such as algae, mold, lichen, ect

Non-organic are stains that are not a living organism, such as atmospheric pollution, grease stains, oxidation, ect.

In this training we will talk about the basic chemicals that are used in the softwashing cleaning solutions.


Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants.

Surfactants are practically used in this industry in our cleaning solution to:

Create foam, which can allow us to see better where and how much solution is being applied.

Increase dwell time. For example, when cleaning a steep roof adding more surfactant can slow the run off allowing less solution to be used, which in turn can help eliminate lanscape damage, and using less solutin also helps our bottom line.

Surfactants also help the Sh or the other chemicals being used to more effectively penetrate deeper.

Surfactans also help in the rinsing process.

Secret Agent


When cleaning we often come upon non organic stains. SH will have little to no effect on these stains. So it becomes necessary to use other products to deal with these stains.

De-greasers are an effective means of cleaning non organic stains.

It is important that when mixing a degreaser in your softwash mix that contains SH, that a SH friendly degreaser is used.

Non Caustic vs Caustic

There are non caustic and caustic de greasers available. We will deal with this in more depth in a later training. But for now we will only use non caustic SH friendly degreasers in our  softwash cleaning solutions.

Scent Cover

It is important to understand the importance of smell and the effect that smell has when cleaning.

When most people smell what they consider is bleach, it causes concerns as to a harmful product being used around their home, pets, children, and possessions.

Scent cover is often added to the cleaning solution to mask the smell of the SH, and to leave the property smelling appealing after the cleaning.

Also as the organic substances are being killed they can also develop a smell of there own, scent cover helps to eliminate these smells also.

SH Enhancers

Bleach enhancers can be added to cleaning solutions for several reasons:

To achieve a higher percentage of cleaning power with a lesser SH percentage. This can be useful to help to keep the potential damage of landscaping lower.

Some shingle manufactures recommend an approx. 2% when it usually takes a 3%-4% to effectively clean shingles.

To reduce SH consumtion

To activate the SH in lower temperatures

Bleach Neutralizer

As much as SH is an effective cleaning agent there are some areas that we have to watch as we use it to clean.

SH has a tendency to leave spots and hazy residue on glass, vehicles and other surfaces. Rinsing well, defiantly aids in the in eliminating these effects.

Continuous exposure to SH can cause rusting and other damage on vehicles and other surfaces that the SH may come into contact on a regular basis.

SH will also shorten the lifespan of pumps, hoses, valves, ect.

Bleach Neutralizer can be an effective remedy  to the negative effects of SH.

Bleach Neutralizer can be used to:

Rinse Windows

Wash Trucks 

Rinse out Equipment 

Deal with over spray 

Neutralize Bleach

to name a few.....

Do not mix Bleach Neutralizer in your softwash solution as it will neutralize the effects of the SH and therefor not clean.



Since softwashing is primarily used to clean organic substances, and SH is the cleaning chemical of choice we refer to the amount of SH is being used to get the effective cleaning in a percentage.

For example the percentage that is used on mild to moderate cleaning on vinyl, we use a 1% SH solution.

No mater watch concentrate we purchase the SH in, whether is is 6% or 10% we are then able to caculate the dilution required to get to the require softwash percentage, such as 1%.

So in this training with will be using terns such as 1%,2%,3%,ect.

The maximum percentage solution that you can achieve is limited to the  the percentage of the SH that you are using to mix. For example if you purchase a 6% solution the maximum solution that you can achieve is a 6%. Likewise if your source SH is 10% then the maximum solution can be 10%. 

For most of the cleaning that we do a 1%-4% is adequate.


Remember that SH does deteriorate. So when mixing just because the SH was originally was purchased as 10%, does not mean that 2 months later it will be the same. Through time with experience you will learn how each percentage cleans and then became suspicious that the solution may not be the original strength.


•Painted Surfaces 


•Screen Enclosures 




•Other lightly stained surfaces


•Durable Painted Surfaces 







•Flat Membrane Roofs

•Cedar Shake Roofs






•Pool Decks 





•Non glazed color Tile roofs 

•Hardy dirty surfaces

Match the

  • Softwash
    Shingle Roofs
  • Pressure Washed
  • Softwash
  • Pressure Washed