Spalling is the symptom, not the full diagnosis
Spalling is concrete breaking, flaking, or separating from the surface. It may show as shallow scaling, exposed aggregate, broken edges, hollow-sounding material, or deeper concrete loss.
The repair should start by identifying what concrete is still sound. Placing repair material over loose or contaminated concrete usually creates another weak layer.
Water and embedded steel can expand the damage
Water can enter cracks, edges, joints, coating failures, and post penetrations. When steel corrodes, the expansion can push concrete outward and create a blowout or spall.
Not every spall is structural, but exposed reinforcement, edge failure, movement, or repeated water exposure should be reviewed carefully.
Repair depends on depth, edges, and surrounding use
A repair may require controlled removal, cleaning exposed steel, forming edges, repair mortar selection, curing, sealant, coating, or broader replacement.
Color, texture, aggregate, and weathering can make exact matching difficult. The written proposal should state the expected finish and whether coating, broader resurfacing, or adjacent work is included.
The customer question
The practical question is not simply why the surface is flaking. The question is whether the damaged area is shallow and stable enough for a localized repair, or whether water, embedded metal, edge failure, or repeated patch history means the scope needs to be broader.
Visible conditions to document
Look for loose edges, hollow-sounding areas, exposed aggregate, rust staining, exposed steel, cracks entering the spall, ponding, coating failure, and prior repair lines.
A site evaluation becomes more appropriate when spalling appears in several locations, affects walking surfaces, exposes reinforcement, or is connected to railings, walls, drains, balconies, stairs, or occupied common areas.
Related trades and photos to send
Spalling can overlap with railings, waterproofing, stucco, coatings, sealants, drainage, landscaping, or painting. Those related conditions should be shown in the photo set, even when the requested work is concrete repair.
Send one wide photo, two close-ups, one tape-measure photo, any water-source photo, and one photo showing nearby posts, drains, walls, thresholds, or coatings. The conclusion should stay qualified until the unsound concrete can be verified.