Every large construction project produces the same glass problem at the end. The building is structurally complete, the interior fit-out is finishing, and someone walks the glazing and finds scratches. Sometimes it’s the construction cleaning crew that caused them – metal tools, abrasive pads, or debris dragged across the surface during the post-construction wipe-down. Sometimes it’s the build itself: drywall dust, metal filings, scaffold contact. By the time the damage is documented, the cause is usually unclear and the question is the same regardless: replace or restore.
On large-format panoramic glazing at a development site, that question has a significant cost asymmetry attached to it. Custom panels measured, manufactured, and installed in a building that’s already enclosed are expensive. Lead times stretch. Work has to be coordinated with the facade contractor. The schedule for handover moves. Restoration – grinding and polishing the existing glass in place – costs less, takes less time, and doesn’t require anyone to reopen the building envelope.
Total Window Service was brought in to restore panels across the site. Scissor lifts provided access to the elevated glazing. The scope was multi-panel, with scratches ranging in depth across different sections of the building.
How Construction Scratches Happen
The mechanism matters because it determines what the restoration has to do.
Construction scratches are mechanical. Something harder than glass – a metal tool edge, a piece of debris caught between a cleaning pad and the surface, a scaffold component making contact – dragged across the glass and cut a groove. The glass surrounding the groove is structurally unaffected. The scratch is a valley in the surface, not a zone of chemically or thermally altered material.
This is different from acid etching, where the damage is a dissolved zone, or from sparks damage, where a fused deposit has bonded to the surface with a thermal stress ring around it. Mechanical scratches require mechanical removal: grinding the surface down to the depth of the scratch, then rebuilding the optical quality of the surface through progressively finer abrasive stages and final polishing.
The depth of the scratch determines how much glass has to be removed and how long each panel takes. A shallow scratch from a cleaning cloth with grit embedded in it comes out in the polishing stage alone. A deep gouge from a metal tool edge requires grinding through the full depth before polishing can begin. On a construction site where multiple trades have been through the building, the scratch population across a panel is usually mixed – some shallow, some deep, some in between.
The Grinding Sequence
Frame edges were protected before any tool touched the glass. The abrasive work happens close to the frame on any panel where scratches run to the edge, and the aluminum or other frame material surrounding the glass is softer than glass – a grinding disc that strays off the glass surface damages the frame finish. Tape and protective material on the frame perimeter before work begins is not optional.
The sequence opened with black discs – coarse grit, aggressive material removal. The black disc cuts down through the scratch to undamaged glass below. This is the stage that actually removes the damage. It’s also the stage that leaves the surface in the worst condition it will be in at any point during the restoration: a uniform matte grey, the original scratch replaced by the coarser scratch pattern of the abrasive disc.
That intermediate condition – the haze – is the expected result of correct grinding technique. It means the original scratch has been removed and the surface has been leveled. A panel at this stage looks worse than it did with the original construction scratch, which is the source of most client anxiety on restoration projects. The haze is not the final result; it’s confirmation that the grinding phase worked.
The pre-polish stage followed with finer grit, removing the coarse scratch pattern from the black disc and bringing the surface geometry closer to the tolerances required for optical clarity. Each stage is doing less material removal and finer surface refinement than the one before it.
White discs and polishing powder finished the sequence. The rotary head works the compound into the surface, the matte grey disappears, and the glass goes transparent. The transition from haze to clarity happens progressively as the polishing compound works – first a general improvement in light transmission, then the surface reading as glass rather than frosted material, then optical consistency with the undamaged areas surrounding the repair zone.
The check at this stage is done from inside the building. External viewing angle and lighting conditions can mask residual haze that’s visible when you’re inside looking out through the panel. Interior verification with the panel backlit by the sky is the correct quality check – if it reads as clear glass from inside, the restoration is complete.
Scissor Lifts on a Construction Site
Access to elevated glazing at a development site is a different operating environment than a finished occupied building. The site is still active – other trades may be working, the floor surfaces are construction grade, power and utilities may not be fully commissioned.
Scissor lifts provide stable elevated platforms for glass restoration work where rope access isn’t necessary and where the floor surface supports the equipment. On a development site, the concrete floor slabs are typically accessible and load-rated for construction equipment, which makes lift operation straightforward. The lift positions against the facade, the platform raises to working height, and the technician has a stable surface to work from with both hands free for the restoration tools.
The limitation of scissor lifts relative to rope access is lateral coverage – a lift covers the section of facade directly above its ground position, and repositioning requires lowering the platform, moving the equipment, and raising again. On a multi-panel scope across an entire building, the number of repositions adds time to the project. The tradeoff is stability: restoration work on large panels benefits from a fixed platform position where the technician isn’t managing body position against the glass simultaneously with tool pressure and rotation speed.
What the Developer Avoided
Custom large-format glazing replacement at a development site involves more than the panel cost. The glass has to be ordered to the specific dimensions of the opening – these are not stock sizes. Delivery lead time on specialty glazing in the current market can run weeks to months. Installation requires a facade contractor, potentially crane access depending on floor height, and coordination with the building schedule that may push handover.
Against that alternative, professional glass restoration on the existing panels delivered clean glazing on a construction timeline. The panels stayed in place. The building envelope stayed intact. The schedule stayed intact.
The restored panels, verified from inside the building, read as new glass. The scratches that were documented in the pre-restoration walkthrough are gone.