Whether it’s a retail storefront, office complex, or government building, the appearance of your building speaks volumes. Over time, environmental pollutants such as vehicle exhaust, smoke, mildew, algae, and grime build up on exterior surfaces, which not only creates a poor first impression it can also lead to long-term wear and expensive repairs if left untreated.
Pressure washing is often the go-to solution for cleaning building exteriors, as well as roofs, parking areas, common areas, and other aspects of a property. For hard surfaces such as concrete, high pressure washing provides a thorough cleaning that removes or lightens many types of stains as well as surface grime and pollen.
However, high pressure washing is not ideal for more delicate surfaces like siding, stucco, vinyl, wood, and most roof materials. In this case, soft washing is a safer yet still highly effective cleaning method.
What’s the Difference Between Soft Washing and Pressure Washing?
At first glance, soft washing and pressure washing might look similar—but they differ fundamentally in how they clean. Pressure washing uses highpressure water jets—typically 1,300–3,100 psi or more—to blast away tough grime, stains, buildup, and even paint. The force alone does most of the cleaning. It can remove physical debris quickly and is ideal for concrete, brick, or steel surfaces.
Soft washing, on the other hand, is a cleaning method that uses low pressure—usually under 500 psi, often in the range of 150–300 psi—with specially formulated cleaning solutions to chemically break down dirt, grime, and organic growth rather than force it off. This approach kills mold, algae, mildew, and bacteria at the root and leaves a residual treatment that prevents regrowth for weeks or months.
When it comes to which method to use, pressure washing or soft washing, the material being cleaned dictates the choice. Soft washing is safer for delicate surfaces—vinyl siding, stucco, wood trim, architectural foam panels, and asphalt or tile roofs—compared to highpressure methods that risk etching, chipping, or voiding warranties.
Pressure vs. Soft Washing: Quick Reference Guide
|
Surface / Asset |
Soft Washing (LowPressure |
Pressure Washing (HighPressure) |
|
Asphalt shingle roof |
✅ Safe, kills algae at root |
❌ Can strip granules, void warranty |
|
Tile / metal / membrane roof |
✅ Safe if done correctly |
❌ May damage coatings or sealants |
|
Vinyl / stucco / wood siding |
✅ Mild, preserves paint, kills spores |
❌ Risk of etching, peeling |
|
EIFS / foam panels |
✅ Safe chemical action |
❌ High risk of substrate damage |
|
Brick / painted brick |
✅ Gentle, effective on |
⚠️ Use lowpressure only |
|
Concrete / asphalt surfaces |
⚠️ Slow, shallow cleaning |
✅ Fast, ideal for deep stains |
Soft washing is exceptionally well suited to the range of materials you’ll find in commercial settings, especially with regard to:
Roofs
Soft washing is recommended as a safe method for cleaning all manner of roofing materials including asphalt shingle, tile, metal, membrane, and flat commercial roofs. Soft washing kills algae and moss without stripping protective granules or voiding warranties.
Wall Cladding & Siding
Vinyl, wood, stucco, EIFS, painted brick, and fiber cement surfaces in retail storefronts, offices, schools, and medical facilities benefit from soft washing’s gentle yet effective cleaning.
Decorative Architectural Elements
Delicate trim, moldings, decorative plaster, and wood framing around windows or entrances can all be treated without risk with soft washing. The decorative elements are often part of government buildings or historic architecture.
How Soft Washing Works: The Science and Process
Soft washing is typically a multi-step process, although a trained professional with the right equipment can make quick work of any soft washing project.
Step 1: Surface Preparation & Protection
Before any chemicals are applied, surrounding vegetation is pre-soaked with water and, if necessary, neutralized. This protects landscaping from potential damage by any runoff from bleach or surfactants.
Step 2: Mixing the Solution
A typically biodegradable mix includes sodium hypochlorite (bleach), surfactants, sometimes oxidizers, and neutralizers. Surfactants reduce surface tension, allowing the solution to cling to and penetrate mold, algae, and bacteria.
Step 3: Application & Dwell Time
Using a low-pressure pump and nozzle (0°, 15°, or 40° softwash tips), the solution is sprayed evenly over the surface to be cleaned. The chemical action is given time—usually 5 to 10 minutes—to kill organisms at the root before rinsing if needed.
Step 4: Gentle Rinse (when appropriate)
Depending on the surface and job scope, the area may be lightly rinsed with soft water. In many cases, the dwellonly approach is sufficient, and the chemicals degrade harmlessly over time.
Benefits of Soft Washing for Commercial Properties
For commercial buildings such as retail storefronts, offices, schools, medical facilities, managed properties, industrial premises, or government buildings, soft washing offers several advantages as part of a routine property maintenance plan.
Material Protection
Soft washing preserves sensitive materials such as vinyl, wood, stucco, EIFS, painted brick, architectural foam panels, and is the method recommended for asphalt shingle or tile roofs, per the Asphalt Roofing Manufacturers Association (ARMA).
Residential-Grade Safety on Large Premises
Soft washing safely removes moss, algae, pollen, mold, mildew, and organic stains without the risk of etching or stripping paint, which is especially important on storefront façades, narrow architectural detailing, and windows.
Long-lasting Fungicidal Effect
Soft washing doesn’t just clean—it kills spores and leaves a residually effective barrier against regrowth, reducing cleaning frequency and labor costs over time.
Safe Solutions
Many soft wash solutions are biodegradable and safe for vegetation, minimizing environmental impact compared to high-volume water use and runoff from pressure washing.
Reduced Liability and Risk
Using lower pressure means less risk of damaging surfaces, which is important to maintain property value and avoid unnecessary repairs or unsightly results.
How Commercial Customers Use Soft Washing
At Window Hero, our teams are trained and well-equipped to provide both high pressure washing and soft washing, depending on the surface needing to be cleaned. For soft washing, here are the most common areas where this method is recommended.
Retail Storefronts & Shopping Centers
Soft washing cleans delicate architectural brick, painted façades, awnings, signage, and vinyl siding without high-pressure damage. The treatment resists mold and mildew—critical in high-humidity climates.
Government & Municipal Buildings
Soft washing is recommended to preserve historical finishes, stone veneer, stucco trim, and architectural details while meeting environmental and safety standards. It also leaves behind a microbial-resistant surface that is important in public spaces.
Managed Properties & HOAs
HOA communities and managed residential communities often include older wood-clad structures or panel systems where pressure washing could cause damage. These locations may also feature a wide range of materials, from vinyl façades to stucco, metal roofing, and trellises. Soft washing provides a consistent and safe clean across these various materials.
Office Campuses
Low pressure cleaning of exterior windows, wood siding, lobby entryways, and roofs helps maintain a professional aesthetic, as well as compliance with building codes, without damage to surfaces.
Industrial Facilities
Soft washing is useful on metal siding and paneling, especially when the goal is to remove mold, mildew, or pollen without stripping paint or risking operator injury. High pressure methods can be used selectively on concrete or hard surfaces if needed.
Universities & Medical Facilities
Schools and healthcare facilities often have higher standards for cleaning and sanitation, even outdoors. Soft washing removes dirt and contaminants from windows, screens, solar panels, metal roofs, awnings, and building siding, ensuring cleaner surfaces without harsh chemicals or high-pressure blasting.
Pressure or Soft Washing? Your Best Bet is an Experienced Professional
Soft washing is the gentle powerhouse of commercial exterior cleaning. It is especially effective for our biologically stained surfaces as well as delicate surfaces where pressure washing would cause damage. With low-pressure application, biodegradable chemical blends, and residual fungicidal protection, soft washing offers safe, effective, long-lasting results.
Where concrete driveways or pavement need deep cleaning, pressure washing still has its place—best used selectively and by experienced operators. For many façades and sensitive materials, soft washing is the preferred solution.
At Window Hero, we specialize in revitalizing commercial exteriors with cleaning methods tailored to the material and condition of each surface. From pressure washing durable concrete to soft washing siding, roofing, and other delicate surfaces, our team uses the safest, most effective approach for every job. For multi-level buildings and challenging areas, we also deploy advanced drone technology, allowing us to clean safely and efficiently where traditional crews can’t reach.
Contact your local Window Hero team to find out whether pressure washing or soft washing is right for your property.