BLOG POST: WHAT IS SOFT WASHING?
Soft Washing
Explained
Soft washing is a professional exterior cleaning method that uses low-pressure water combined with specialized cleaning solutions to safely remove algae, mold, mildew, moss, lichen, dirt, and other organic growth from exterior surfaces. This makes it particularly useful for delicate surfaces such as vinyl siding, painted surfaces, stucco, roofs, soffits, fascia, and other materials that could potentially be damaged by excessive pressure. By treating the source of organic growth rather than simply blasting away what is visible on the surface, soft washing can provide a deeper, more thorough clean while minimizing unnecessary stress on the exterior materials of a home or building.
Soft Washing Information
What Is Soft Washing and How Does It Work?
Soft washing is a professional exterior cleaning method designed to remove algae, mould, mildew, moss, lichen, dirt, pollen, spider webs, and other organic buildup without relying on aggressive water pressure. Instead of attempting to blast contamination away, soft washing uses low-pressure water combined with carefully selected cleaning solutions that treat the organic growth responsible for many of the dark streaks, green staining, and discolouration commonly seen on homes and buildings.
The biggest difference between soft washing and traditional pressure washing is where the cleaning power comes from. Pressure washing relies primarily on the mechanical force of water, while soft washing relies more heavily on the cleaning solution itself. Once applied, the solution is given time to work on the contamination before the surface is thoroughly rinsed using controlled pressure.
Soft Washing vs. Pressure Washing
Soft washing and pressure washing are both valuable exterior cleaning methods, but they are intended for different surfaces and different types of contamination. High-pressure washing is generally better suited to durable surfaces such as concrete, certain masonry surfaces, parking areas, and other hard materials capable of handling greater pressure. Soft washing is typically preferred for more delicate exterior materials where excessive pressure could cause unnecessary damage.
Using too much pressure on siding, painted surfaces, roofing materials, soffits, fascia, or other vulnerable components can potentially cause damage or force water into areas where it doesn't belong. Professional exterior cleaning is therefore less about using the most powerful equipment possible and more about selecting the appropriate cleaning method for each surface.
What Surfaces Can Be Soft Washed?
Soft washing can be used on many common exterior building materials, including vinyl siding, aluminum siding, painted surfaces, stucco, soffits, fascia, exterior trim, and certain roofing materials. The exact process should always be adjusted according to the material being cleaned and its existing condition.
A property may also require several cleaning techniques during the same project. Siding might be soft washed while nearby concrete is pressure washed, for example. Understanding which method is appropriate for each material is an important part of professional exterior cleaning.
What Does Soft Washing Remove?
One of the primary reasons soft washing has become so popular is its effectiveness against organic contamination. The green staining frequently found on siding is often associated with algae and other biological growth rather than ordinary surface dirt.
Exterior surfaces can also accumulate mould, mildew, moss, lichen, pollen, airborne contaminants, insect residue, dirt, and environmental staining. Because soft washing uses cleaning solutions designed to treat organic material, it can address contamination differently than simply spraying the surface with water.
Not every stain is organic, however. Rust, oxidation, efflorescence, oil, mineral deposits, and other specialty stains may require completely different products and cleaning processes.
Why Does Algae Grow on Siding?
Moisture and shade create favourable conditions for organic growth. This is why some sides of a house can become noticeably dirtier than others. Areas receiving limited sunlight may remain damp longer after rain, morning dew, or humid weather. Trees and vegetation surrounding a property can further reduce sunlight and airflow while introducing pollen and other organic material. Over time, this can result in the familiar green or dark appearance commonly seen on siding, particularly around shaded portions of a building.
Why Low Pressure Matters
More pressure doesn't necessarily mean better cleaning. Excessive pressure can potentially damage siding, remove paint, disturb exterior finishes, damage softer building materials, or drive water behind siding and around windows and doors. Even durable-looking surfaces can have vulnerable joints, seals, vents, trim, and other components. Soft washing reduces the need for aggressive mechanical force by allowing the cleaning solution to perform much of the work. The objective is to achieve a thorough clean while using only the amount of pressure appropriate for the material.
How Does the Soft Washing Process Work?
A typical soft washing process begins with an assessment of the property. The technician identifies the exterior materials, areas of organic growth, landscaping, windows, doors, electrical components, and anything else requiring additional consideration.
Plants and sensitive areas may be pre-wet or otherwise protected before the cleaning solution is applied. The solution is then distributed across the appropriate surfaces and allowed sufficient dwell time to work on the contamination. Afterward, the treated surfaces are thoroughly rinsed. Depending on the surface and type of buildup, certain areas may require additional treatment or specialized cleaning.
Can Soft Washing Be Used for Roof Cleaning?
Soft washing techniques are commonly associated with professional roof cleaning because roofing materials generally should not be subjected to unnecessary high pressure. Dark streaking and organic growth can develop across roofing surfaces over time. Rather than aggressively pressure washing the shingles, an appropriate roof-cleaning treatment can target the contamination using a much lower-pressure application. Roof cleaning requires additional considerations involving roofing material, pitch, drainage, landscaping, runoff, accessibility, and worker safety, so it should not automatically be treated exactly the same as washing siding.
How Often Should a House Be Soft Washed?
There is no universal schedule because exterior conditions vary significantly from one property to another.
Homes surrounded by trees or located in shaded, damp environments may develop organic growth faster than properties receiving abundant sunlight and airflow. The orientation of the house, nearby vegetation, local weather conditions, siding material, and previous buildup can all influence how frequently cleaning is needed. Rather than cleaning according to a rigid calendar, homeowners can monitor their exterior for visible green algae, dark staining, mildew, dirt, spider webs, and general discoloration.
Will Soft Washing Remove Every Stain?
No exterior cleaning method can guarantee removal of every type of staining.
Soft washing is particularly effective against many forms of organic contamination, but some discolouration may come from oxidation, rust, mineral deposits, paint deterioration, permanent staining, or deterioration of the underlying material. Identifying the cause of a stain before treating it helps determine whether standard soft washing, specialty stain removal, restoration, or another process is appropriate.
Does Soft Washing Last Longer Than Pressure Washing?
The answer depends on what is being cleaned. When dealing with organic growth, simply removing what is visible with water pressure may not address the contamination in the same way as an appropriate cleaning treatment. Soft washing is designed around treating organic buildup rather than relying solely on mechanical removal. However, exterior surfaces will naturally become dirty again. Rain, humidity, pollen, trees, insects, airborne contaminants, and changing seasons continuously expose buildings to new contamination.
Can You Soft Wash a Commercial Building?
Soft washing isn't limited to residential properties. The same general principles can be applied to appropriate commercial buildings, retail storefronts, offices, multi-unit residential buildings, institutional properties, agricultural buildings, and other exterior surfaces. Commercial projects can require different equipment, access methods, water management, scheduling, and safety procedures, but the underlying principle remains the same: match the cleaning process to the surface rather than automatically using high pressure.
Is Soft Washing Better Than Pressure Washing?
Neither method is universally "better." They're different tools for different jobs. Pressure washing can be extremely effective on appropriate hard surfaces, while soft washing provides an alternative for surfaces and contaminants that don't require aggressive pressure. In many professional exterior cleaning projects, both methods are used. Ultimately, good exterior cleaning comes down to understanding what the surface is made from, what is causing the staining, and which cleaning method can address it without unnecessarily stressing the material.
Soft Washing: FAQ's
What Is Soft Washing?
Soft washing is an exterior cleaning method that uses low-pressure water and specialized cleaning solutions to remove algae, mould, mildew, moss, lichen, dirt, pollen, and other organic buildup. Unlike traditional pressure washing, soft washing relies primarily on the cleaning solution rather than high water pressure to clean the surface.
What Is the Difference Between Soft Washing and Pressure Washing?
The main difference is how the cleaning is accomplished. Pressure washing uses the mechanical force of high-pressure water, while soft washing uses lower pressure combined with cleaning solutions. Pressure washing is generally better suited to durable surfaces such as concrete, while soft washing is commonly used for siding, roofs, painted surfaces, soffits, fascia, and other more delicate exterior materials.
What Surfaces Can Be Soft Washed?
Soft washing can be appropriate for many exterior surfaces, including vinyl siding, aluminum siding, stucco, painted surfaces, exterior trim, soffits, fascia, and certain roofing materials. The cleaning solution, concentration, application method, and rinsing procedure should always be adjusted for the particular material being cleaned.
Does Soft Washing Remove Green Algae From Siding?
Yes. Removing green algae and other organic growth from siding is one of the most common uses for soft washing. The cleaning solution treats the organic contamination before the siding is thoroughly rinsed using controlled water pressure.
Can Soft Washing Remove Mold and Mildew?
Soft washing can be effective at treating many types of exterior mould, mildew, algae, and other organic contamination. However, staining caused by oxidation, rust, minerals, deteriorating paint, or other non-organic sources may require a different cleaning or restoration process.
Is Soft Washing Safe for Vinyl Siding?
When performed correctly, soft washing is well suited to vinyl siding because it avoids unnecessarily aggressive water pressure. Care still needs to be taken around windows, doors, vents, electrical components, damaged siding, and other vulnerable areas of the exterior.
Can You Soft Wash a Roof?
Soft washing techniques are commonly used for appropriate roof-cleaning applications because excessive pressure can damage certain roofing materials. Roof cleaning requires its own procedures for chemical application, runoff management, landscaping protection, access, and safety.
Why Shouldn't You Pressure Wash House Siding?
Using excessive pressure on siding can potentially damage the material or force water behind siding, around windows, into vents, and through vulnerable areas of the building envelope. A lower-pressure cleaning process allows organic contamination to be treated without relying on aggressive water pressure.
Does Soft Washing Remove Black Streaks?
It depends on what is causing the streaks and the surface they're growing on. Many dark streaks associated with organic contamination can respond well to appropriate soft washing treatments. Other stains may require specialized products or restoration techniques.
Does Soft Washing Use Bleach?
Some professional soft washing processes use sodium hypochlorite-based cleaning solutions because they can be effective against organic growth. The appropriate product and concentration depend on the surface, contamination, surrounding materials, and environmental conditions. Proper application and thorough rinsing are important parts of the process.
Is Soft Washing Environmentally Friendly?
The environmental impact depends on the cleaning products being used and how they're handled. Professional exterior cleaning should consider chemical concentration, water usage, runoff, vegetation, nearby waterways, and surrounding property when determining the appropriate cleaning procedure.
Is Soft Washing Better Than Pressure Washing?
Neither method is inherently better. They serve different purposes. Soft washing is particularly useful for organic contamination and surfaces that should not receive excessive pressure, while pressure washing can be highly effective for durable materials such as concrete. Professional exterior cleaning often involves using both soft washing and pressure washing where each method is appropriate.
