What Is Actually on Your Facade
Atmospheric soiling — carbon and particulate from traffic and HVAC exhaust — is heaviest on buildings along I-95, the Schuylkill Expressway, Route 130 and the Wilmington corridor. Biological growth of algae and mildew appears on north and east elevations and anywhere irrigation overspray keeps a wall damp. Rust and metal staining bleed from anchors, fasteners, railings and rooftop equipment. Efflorescence is white mineral bloom pushed out through masonry as moisture migrates. Water tracking maps where your envelope is shedding water incorrectly — useful information a good contractor reports rather than just cleans over.
Method by Cladding Type
Brick and CMU take soft wash at low pressure — watch mortar condition and older lime mortar. EIFS is soft wash only: thin coat over foam, it dents and holds water. Stucco is soft wash only: porous, hairline cracking. Metal wall panel needs controlled chemistry at low pressure — watch finish warranty and coating compatibility. Anodized aluminum needs neutral cleaners since alkaline products can stain permanently. The single most common failure in commercial facade work is treating the whole building as one surface. Most buildings in this region are at least two: a masonry or panel field with a glass and mullion system running through it.
Access Is the Real Cost Driver
Swing stage and suspended scaffold are traditional, capable, and slow to mobilize — requiring rigging, roof anchor certification and often a permit. Boom lift is fast for low and mid-rise where there is ground to set up on. Drone systems reach the elevations the others cannot without rigging, anchors, street closure or lift setup — no scaffolding, no anchor certification queue, and far less tenant disruption. Drone-based facade and glass work often lands materially below crew-and-rigging methods on comparable scopes, frequently in the range of a quarter to a third less.
See also: High-Rise Window Cleaning Methods Compared · Drone Cleaning vs Scaffolding · What Is Drone Cleaning?
Regulatory Items That Catch Owners Out
Wash water discharge: facade wash water carrying cleaning agents is generally not permitted to enter a storm drain. PA DEP, NJDEP and Delaware DNREC all administer stormwater programs under the federal NPDES framework. Historic districts in Philadelphia, Wilmington, and borough historic districts across Chester and Montgomery counties frequently require review for cleaning methods on designated structures. Drone operation under FAA Part 107 requires airspace authorization near Philadelphia International, Wilmington, Northeast Philadelphia and Trenton-Mercer.
See also: Drone Cleaning Regulations · Commercial Pressure Washing Philadelphia