Commercial building washing is not a single service — it is a category of services that encompasses fundamentally different methods, chemistry, and equipment, each appropriate for specific surface types and contamination conditions. Treating all exterior building cleaning as interchangeable is the primary reason surface damage occurs in commercial washing projects. When the wrong method is applied to the wrong surface, the consequences range from cosmetic (streaking, surface discoloration) to structural (EIFS delamination, mortar joint erosion, cladding failure) — and the repair costs routinely exceed the cleaning cost by a factor of ten or more.
Property managers, building owners, and facilities directors who understand the distinction between pressure washing, soft washing, and steam cleaning are better equipped to specify the right service, evaluate contractor proposals intelligently, and protect their buildings from cleaning-related damage. This guide provides a technically accurate explanation of each method and a surface-by-surface application guide for the most common commercial building cladding types.
Pressure Washing
Pressure washing uses mechanical force — high-pressure water — as the primary cleaning mechanism. The working pressure range for commercial pressure washing typically spans from 1,000 PSI on the low end (appropriate for softer surfaces and light contamination) to 4,000 PSI on the high end (appropriate for heavy concrete, masonry, and industrial surfaces). Most commercial building work falls in the 1,500–3,000 PSI range.
Water volume — measured in gallons per minute (GPM) — matters as much as pressure for effective cleaning. Higher GPM at moderate PSI produces better cleaning results with less surface impact than lower GPM at very high PSI. Commercial-grade pressure washing equipment typically delivers 4–8 GPM; consumer-grade equipment delivers 1.5–2.5 GPM. The difference in cleaning efficiency and surface safety is significant.
Pressure washing is most appropriate for:
- Concrete flatwork: parking lots, sidewalks, loading docks, garage floors
- Brick and block masonry at appropriate pressure levels
- Precast concrete building panels
- Metal decking and structural steel in industrial settings
- Parking structures and concrete facades
Risks of misapplied pressure washing include: mortar joint erosion on brick (at PSI above 1,500 directed at joints), paint stripping on painted surfaces, EIFS surface rupture, wood grain raising on wood surfaces, and window seal failure when pressure is directed at window perimeters. A contractor who uses a single pressure setting for all building surfaces is taking a risk with every surface that is not concrete.
Soft Washing
Soft washing uses chemistry rather than mechanical force as its primary cleaning mechanism. Water is applied at very low pressure — typically 40–150 PSI, similar to a garden hose — after or with a cleaning surfactant solution that does the actual work of killing and releasing biological growth (algae, mildew, lichens, mold) and loosening atmospheric contamination from the surface.
The core chemistry in most commercial soft washing systems is sodium hypochlorite (bleach) at dilutions ranging from 1–3% for general biological treatment, combined with surfactants that help the solution cling to vertical surfaces during its dwell period and rinse agents that neutralize the bleach before it contacts landscaping or drainage. More specialized formulations use quaternary ammonium compounds, hydrogen peroxide, or enzyme-based chemistry for specific applications or surfaces where chlorine is contraindicated.
Dwell time is critical to soft washing efficacy. The surfactant-chemistry solution needs to remain on the surface for 5–15 minutes (depending on biological load and ambient temperature) to fully kill organic growth. Rinsing too early leaves living organisms on the surface that will regrow more rapidly than if the surface had been properly treated. A common soft washing failure mode is rushing the process — applying, dwelling for two minutes, and rinsing before the chemistry has completed its work.
Soft washing is the correct method for:
- EIFS and synthetic stucco systems
- Painted surfaces (any substrate)
- Vinyl and composite siding
- Wood surfaces (with appropriate chemistry modifications)
- Roofing materials (asphalt shingle, tile, metal)
- Exterior insulation systems of all types
- Signage and cladding panels with applied finishes
Our soft washing services in Atlanta use method-matched chemistry for each surface type, with dwell protocols calibrated to Atlanta's climate and biological load conditions.
Steam Cleaning
Steam cleaning uses high-temperature water vapor — typically generated at 200–250°F — at low to moderate pressure (150–400 PSI) to clean surfaces. The thermal mechanism is the primary cleaning agent: heat breaks down grease bonds, kills pathogens, and loosens organic contamination that is resistant to surfactant chemistry alone.
Steam cleaning uses significantly less water than pressure or soft washing — typically 0.5–1.0 GPM versus 4–8 GPM for pressure washing. This makes it appropriate for environments where water discharge must be minimized, and for surfaces where excessive water saturation is a concern (below-grade areas, surfaces with drainage limitations).
Commercial applications where steam cleaning is the correct primary method:
- Kitchen exhaust areas and grease trap surrounds on food service buildings
- Dumpster pad and loading dock concrete with heavy grease contamination
- Drive-through lanes at quick-service restaurants
- Healthcare facility exterior surfaces requiring pathogen elimination without chemical residue
- Gum removal from concrete sidewalks and entry areas
- Engine bays and industrial equipment yards
Steam cleaning is not the most efficient method for large surface area cleaning — the low GPM rate means coverage is slow. It is best applied as a targeted treatment for specific contamination types (primarily grease) or for precision cleaning of defined areas rather than wholesale building facade cleaning.
Matching Method to Cladding Type
Glass Curtain Walls
Glass curtain wall systems — common on mid-rise and high-rise commercial office buildings in Atlanta — require a gentle approach that cleans the glass without damaging the aluminum framing, silicone glazing seals, or any EIFS infill panels between glass sections. High-pressure washing directed at curtain wall perimeter seals can force water into the wall assembly, causing interior water intrusion that requires expensive remediation.
The appropriate protocol for curtain wall cleaning is low-pressure rinse (under 500 PSI) combined with appropriate glass cleaning chemistry. For large curtain wall areas, squeegee systems using pure water (deionized or reverse osmosis purified) produce streak-free results without chemical application. The reach-and-wash pole system, using purified water fed to a brush head on an extendable pole, is the preferred method for ground-accessible curtain wall surfaces up to approximately 60 feet.
EIFS and Synthetic Stucco
Exterior Insulation and Finish Systems (EIFS), also called synthetic stucco, are among the most common commercial building cladding types in metro Atlanta — and the most frequently damaged by improper cleaning. EIFS consists of a foam insulation board substrate, a base coat with fiberglass mesh reinforcement, and a textured finish coat. The finish coat is only 1/16 to 1/8 inch thick and is easily damaged by pressure above 500 PSI at close range.
EIFS must be soft washed exclusively. Before any cleaning work begins, a qualified contractor should inspect the EIFS for existing cracks, delamination, or failed caulk joints that would allow water to penetrate the assembly. Water intrusion behind EIFS causes the foam substrate to retain moisture, creating conditions for serious mold growth and structural degradation. If seal inspection reveals compromised caulk joints, these must be repaired before any wet cleaning is performed.
Precast Concrete Panels
Precast concrete building panels — common in 1970s and 1980s commercial construction and still widely used in industrial and institutional buildings — respond well to medium-pressure washing in the 2,000–2,500 PSI range. The primary surface issue on precast is efflorescence: white calcium carbonate deposits that migrate to the surface as water moves through the concrete and evaporates. Efflorescence is not removed by pressure washing alone; it requires a mild acid treatment (typically a 5–10% phosphoric acid solution or proprietary efflorescence remover) applied before pressure washing to dissolve the mineral deposit.
Precast concrete is also subject to atmospheric carbonation staining — dark deposits from vehicle exhaust particulate that accumulate on ledges, horizontal reveals, and lower panel sections near parking areas. These respond to alkaline degreasing chemistry applied before pressure washing.
Brick and Mortar
Brick masonry tolerates pressure washing well at appropriate pressures (1,200–2,000 PSI), but mortar joints require careful attention. Older mortar (pre-1980 formulations) is frequently softer than modern mortars and can be eroded by pressure washing at 2,000+ PSI directed perpendicular to the joint. The correct technique for brick washing is to keep the lance at a 45-degree angle to the surface and maintain a distance of at least 12 inches from the surface to prevent mortar erosion.
New brick construction from the 1990s onward typically uses harder Portland cement mortars that tolerate higher pressures, but the general principle of avoiding direct lance pressure on mortar joints applies regardless of mortar age. Brick cleaning chemistry for biological staining (black or green organic growth) is typically alkaline-based — an oxygen bleach or sodium hypochlorite solution applied and rinsed at low pressure before the pressure wash pass.
Metal Panels and Coping
Aluminum composite panels (ACM), metal coping, and metal soffit panels require low-to-medium pressure (800–1,500 PSI) with non-abrasive cleaning chemistry. Abrasive agents or high-concentration alkaline cleaners can damage the paint or PVDF coating on aluminum panel faces, causing visible surface alteration that cannot be reversed without repainting. Use pH-neutral or mildly alkaline detergents and keep pressure below 1,500 PSI at the surface.
Metal panel systems have perimeter trim and fastener systems that should be inspected during any cleaning engagement for signs of corrosion, sealant failure, or fastener loosening. A thorough cleaning pass provides a valuable opportunity to identify facade maintenance issues before they become water intrusion problems.
Multi-Story Access Equipment
Building washing above ground-floor level requires access equipment that varies in type and cost based on building height, site conditions, and the nature of the work required. Common options in the Atlanta commercial market:
- Boom lifts (articulated and telescopic): Ground-based, self-propelled platforms that can reach building facades at heights of 40–150 feet depending on equipment class. Most practical for buildings with adequate ground-level access and stable ground conditions. Atlanta's commercial campuses typically accommodate boom lift access, but urban infill sites with limited ground clearance may not.
- Spider lifts: Compact, track-mounted platforms with outrigger stabilization that can access confined spaces and navigate tight site conditions. Maximum height typically 50–80 feet. More expensive to mobilize than standard boom lifts but indispensable for sites with limited access.
- Reach-and-wash pole systems: Extendable poles with pure water systems that access building surfaces from the ground up to approximately 60–70 feet without mechanical lift equipment. Lower mobilization cost, suitable for glass and light-duty facade work, limited to surfaces accessible from stable ground.
- Rope access (industrial rope access): Trained technicians descend from building rooftops on rope systems to access facades at any height. Required for buildings where exterior lift access is not possible. In Atlanta, rope access work typically requires a permit and proof of IRATA/SPRAT certification from the technicians performing the work.
In the City of Atlanta, boom lift operations on public rights-of-way require a right-of-way encroachment permit from Atlanta DOT. For multi-story facade work on buildings adjacent to public sidewalks, the contractor is responsible for obtaining this permit and providing adequate pedestrian protection during the work period.
Chemical Safety and Environmental Compliance
All cleaning chemistry used in commercial building washing must be handled, applied, and disposed of in compliance with applicable environmental regulations. The primary compliance areas:
- Storm drain protection: Wash water containing surfactants, bleach, or degreasing chemistry must not enter storm drains untreated. Inlet protection — drain plugs, filter socks, or collection berms — must be deployed before any chemical washing begins.
- Surfactant biodegradability: Choose cleaning products with NSF-rated or EPA Safer Choice certified biodegradable surfactants. These break down rapidly in the environment and satisfy the discharge requirements of most local stormwater management programs.
- Bleach discharge: Sodium hypochlorite at working concentrations (0.5–3%) is regulated under many local stormwater permits as a pollutant. Neutralization — typically with sodium thiosulfate — before discharge or collection and disposal are the compliant approaches depending on local permit requirements.
- Chemical storage and transport: Concentrated cleaning chemicals must be transported and stored in compliant containers with proper labeling and secondary containment. SDS sheets must be carried with all chemicals on work vehicles.
Selecting the Right Contractor
For commercial building washing, contractor selection should include verification of three capabilities beyond standard insurance and licensing: surface-specific method knowledge, appropriate equipment for building height and cladding type, and environmental compliance protocols for wash water and chemical management.
Ask prospective contractors to describe the specific cleaning method and chemistry they would use for each cladding type on your building. A contractor who proposes the same method for EIFS, brick, and glass curtain wall is demonstrating inadequate technical knowledge. Ask specifically how they manage wash water containment and whether they carry inlet protection equipment on their trucks.
Rare Earth Ltd Commercial Capabilities
Rare Earth Ltd provides commercial building washing services in Atlanta with method selection matched to each facade type and contamination condition. We carry both pressure washing and soft washing capabilities, with hot water extraction equipment for grease-heavy applications. Our team is trained in EIFS-safe protocols, brick and mortar care, and glass curtain wall washing procedures.
We serve commercial buildings of all types across metro Atlanta — office, retail, industrial, multifamily, and institutional. Free estimates include a facade assessment and written scope of work identifying the appropriate method for each surface type. Call (678) 748-3578 or email rareearthcontracting@gmail.com to schedule a building assessment.
Method Selection Quick Reference
- Pressure wash (1,500–3,000 PSI): Concrete, precast panels, brick, parking structures
- Soft wash (40–150 PSI + chemistry): EIFS, painted surfaces, vinyl, wood, roofing
- Steam (200°F, low pressure): Grease areas, dumpster pads, gum removal, healthcare surfaces
- Glass curtain wall: Pure water pole system or low-pressure rinse only
- Metal panels: Low-pressure wash (under 1,500 PSI), pH-neutral chemistry