Why commercial smoke losses are a boundary problem
NFPA's data, as reported by the Insurance Information Institute, put non-residential structure fires at 140,000 in 2022, and the defining feature of a commercial smoke loss is that the building is larger than the fire. A restaurant kitchen fire smokes the dining room, the offices above and, through a shared return, two tenant suites that never saw a flame. A warehouse fire across the lot puts residue on the inventory of the building downwind. The question a commercial owner has to answer is not "is there smoke damage" but "where does it stop" — which floors, which suites, which air-handling zones — because every square foot inside that boundary is closed and every square foot outside it should not be.
That boundary is established by sampling, not by walking through with a flashlight. The EPA's indoor air quality guidance for smoke events includes material specific to commercial buildings for the same reason: mechanical systems move smoke in ways the plume's visible path does not predict.
The sampling plan
We start from the floor plan and the mechanical drawings. Zones are defined by what separates them in practice — separate air handlers, fire-rated separations, floors, tenant demising walls — and each zone is sampled independently:
- Surfaces per zone. Tape lifts and wipes from horizontal surfaces, above-ceiling spaces, and the tops of fixtures and casework, read by microscopy to identify soot, char and ash against background dust.
- Mechanical systems. Return plenums, supply diffusers, the filter banks that ran during the event, and rooftop or penthouse units, since a unit that ran pulled the plume into everything it serves.
- Air. Sampling for the volatile fraction — the compounds the EPA groups as VOCs — in zones where odor is reported, compared against an unaffected reference.
- Contents and inventory. Representative sampling of stock, furnishings and equipment, so that the contents claim rests on the same laboratory basis as the building claim.
Every location is photographed, numbered on the plan and logged under chain of custody. The laboratory report comes back zone by zone, which is what lets unaffected space be released with documentation while affected space is scoped.
Scope, remediation and clearance by zone
For zones the laboratory confirms as affected, a licensed industrial hygienist writes the protocol. Remediation is performed by certified professionals — the relevant IICRC credential is the Fire and Smoke Restoration Technician, whose scope covers commercial as well as residential structures — under protocols aligned with ANSI/IICRC S700. Commercial work has its own characteristic items: cleaning of above-ceiling plenums and cable trays, duct cleaning or replacement per the HVAC findings, treatment of acoustic ceiling tile and other porous finishes that usually cannot be cleaned, and phasing so that released zones can operate while affected zones are worked. Each zone is clearance-sampled at the original locations when its work is complete, and released on the numbers.
The documentation package
A commercial smoke loss usually has more than one carrier and more than one clock running. The property carrier wants the scope tied to evidence; a tenant's carrier wants the same evidence for the same space; and the business-interruption adjuster wants dates — loss, zone releases, completion. One file serves all three: the sampling plan on the floor plan, the chain-of-custody records, the laboratory results per zone, the hygienist's protocol, the remediation scope tied to the protocol, and the clearance reports with release dates. We coordinate that package from the first visit so that it exists when it is asked for rather than being reconstructed afterwards.
When the roof or a mechanical penthouse was involved
A fire that reached the roof deck, a rooftop unit or a penthouse adds a structural question that sampling does not answer. Fire department ventilation openings on a flat commercial roof — including the trench cut used to stop a fire spreading down a long building — and heat damage to steel deck or bar joists are an engineer's and a roofer's finding. Our page on the fire-damaged roof sets out who inspects what; the state directory below lists licensed commercial roofing contractors for the inspection.