Ordinary Damage

The underside of a terrace slab in a Brooklyn apartment house:

Without even looking very hard: a leak has rusted the reinforcing mesh, spalling the bottom cover of concrete; the same leak caused enough rust on the beam running diagonally from the center of the right to the center of the bottom to spall the fireproofing concrete cover; the installation of the drain on the far left has cut at least two and maybe three of the main wires of the mesh. That’s a nice catalog of damage for maybe twenty square feet of slab.

Something worthy of note: there has been no movement associated with the damage. That doesn’t mean the slab is okay, as it’s obviously not, but that the damage was not yet observable without removing the hung ceiling. Some combination of whatever capacity is left in the damaged wire, loading that was less than the code mandated levels, and alternate load paths has kept the slab not just standing, but in its proper position.

Food for thought: how many conditions like this exist but aren’t getting repaired right now because no one knows they’re there?