Some buildings reach a point where a single service call isn’t enough. The facade at this commercial property in New York City had accumulated years of neglect: heavy atmospheric grime across the metal cladding, spray paint and marker tags on the lower glazing, and – the problem that changes the scope entirely – acid graffiti etched into the glass surface on multiple panels.
Three separate problems. Three different solutions. One mobilization.
What Was on the Building
The facade combined metal panels with large-format glazing. Both surfaces had suffered. The metal was coated in layered urban grime – the kind that builds up when a building goes years without professional cleaning. The contrast between cleaned and uncleaned sections, visible partway through the job, told the story clearly: the building hadn’t looked like itself in a long time.
The graffiti came in two forms, and the distinction matters.
Standard graffiti – spray paint, oil-based paint, markers – sits on top of the glass surface. It bonds to the glass but doesn’t alter the glass itself. Scraping and solvent work removes it without leaving a trace on the substrate.
Acid graffiti is different. When vandals use an acidic substance on glass, it doesn’t coat the surface – it reacts with it. The silica structure of the glass dissolves within the etched zone, leaving a frosted, clouded mark that is now part of the glass itself. You cannot scrub it off. You cannot dissolve it. The damage is permanent unless the glass surface is physically removed and rebuilt through grinding and polishing.
On this building, both types were present.
How the Work Was Done
Access to the upper sections of the facade required rope descent systems. Technicians rigged from the roof and worked panel by panel across the building exterior.
The heavy-duty cleaning of the metal facade and standard-contaminated glass came first – detergent wash, agitation, rinse. As sections came clean, the visual difference from the still-uncleaned areas confirmed how far the building had deteriorated. The metal panels, once grey and flat, showed their original finish underneath.
Paint and marker graffiti was removed mechanically. Tags were scraped off the glass surface and treated with appropriate solvents where needed. On glass, this process leaves the substrate intact.
The acid-etched panels required a different approach entirely. Each affected panel was assessed for etch depth before any grinding began. Shallow etching responds quickly to polishing compound and a rotary head. Deeper etching requires an abrasive sequence – coarser grit to remove material down through the damaged zone, finer grit to refine the surface geometry, then polishing compound to restore optical clarity.
Surface temperature was monitored throughout. Grinding generates heat, and heat creates thermal stress in glass. The process stops if the temperature climbs – there is no faster way through this constraint without risking the panel.
The Result
By the end of the project, the acid etching was gone. The paint tags were gone. The metal panels and glazing were clean across the full facade.
The before-and-after was not subtle. The sections cleaned first had already dried by the time the crew reached the far end of the building, and the difference between the restored facade and the surrounding streetscape made the transformation obvious.
Why Restoration Instead of Replacement
For the building owner, the decision on the acid-etched panels came down to cost. Large-format commercial glazing is not a stock item. Custom panels have to be measured, manufactured, and delivered – lead times that can stretch weeks. Installation on an occupied commercial building requires coordination with the facade contractor and, depending on floor height, crane access.
Grinding and polishing the existing panels in place costs a fraction of that. The restored glass is optically consistent with undamaged panels. There is no visible seam, no color mismatch, no installation disruption to building operations.
Replacement is the right answer when the damage is too deep, when the panel has existing stress cracks, or when the glazing has a first-surface coating that grinding would remove permanently. On this project, the panels were restorable – and restoring them was the correct call.