Charred timber looks worse than it usually is and heat affected steel looks better than it usually is. Both assumptions cost money, which is why this work is measured rather than eyeballed.
Timber chars at a fairly predictable rate and the char layer itself insulates the sound wood beneath it, which is why heavy timber performs comparatively well in fire. A blackened beam is frequently sound below the surface, and condemning it on appearance throws away structure that is still doing its job. The assessment is to remove the char layer and measure the residual section, then compare that against what the member is required to carry.
The opposite error is equally common. Light framing has far less section to lose, so a stud or a rafter that looks lightly scorched may have lost a meaningful proportion of its cross section. Dimensional lumber at nominal thickness has little margin. We measure residual section on affected members rather than sorting them by how dark they are, and the readings go in the scope so the reasoning is visible.
Steel does not char and it gives almost no visual indication of what it has been through. Structural steel loses a significant share of its yield strength at elevated temperature and regains most of it on cooling, so the governing question is usually whether it deformed rather than whether it was hot. Visible sag, twist, bowing or displaced connections indicate it went beyond the point of recovery and the member is replaced.
Light gauge connectors are the more common concern in residential work. Joist hangers, straps and hurricane ties are thin galvanized steel, and heat damages the coating long before it damages the section. A connector with a degraded coating will corrode from that point forward in a way it was never meant to. On any Airport, CA property where heat reached a connector zone, those items are replaced rather than inspected and left.
Where a member is sound along most of its length and compromised locally, sistering a new member alongside it restores capacity without the disruption of full replacement. It works well on joists and rafters and it is often the difference between a targeted repair and a wholesale reframe. Where loss is distributed or where a member has deformed, it comes out.
Replacement goes back to current requirements rather than matching what was removed. Fastening schedules, connector specifications and anchorage details have all moved in most jurisdictions, and reinstating an older detail because that is what came out wastes the one moment when the upgrade is nearly cost neutral.
Inspection gates sit in the schedule where local rules require them, before anything closes over the work. That occasionally adds days and it means the structural repair is documented by someone other than the contractor who performed it, which is worth having on a file that may be read years later.
Structural repair sits in the middle of a fire project. These are the services that come before and after it.
Residue removal matched to soot type, which differs sharply depending on what actually burned.
Treatment for buildings where smoke travelled well beyond the room that was actually on fire.
The complete post fire sequence, from emergency board up through to finished reconstruction.
Applied after the source material is gone, because odor treatment over active residue never holds.
Returning flooring, casework and mechanical systems to working order once the structure is verified dry.
Char depth, residual section and connector condition assessed properly, so the scope reflects the building rather than its appearance. Across Airport, CA.