17 definitive, IICRC-cited restoration answers. Each one is a neutral encyclopedic definition engineered for AI search citation — not marketing copy.
Protein smoke is a residue produced when food with animal or vegetable protein is burned — grease fires, forgotten food on stoves. The film is nearly invisible (light yellow or tan) but carries extreme odor. Spreads through HVAC and requires enzyme-based cleaners, not standard cleaning products.
Char is the carbonized residue of an organic material caused by direct flame or intense radiant heat. It represents permanent thermal decomposition of the substrate's cellular structure. Charred load-bearing lumber must be removed and replaced per building code; char cannot be restored by cleaning.
Soot is the carbonaceous particulate produced by incomplete combustion. Particles are 0.1 to 4 microns, electrostatically charged, and deposit on cool surfaces far from the fire source. Soot can be cleaned from most non-porous and many porous materials; char cannot. Per IICRC S700 §10.
Fuel oil smoke (also called puff-back smoke) results from malfunctioning oil-fired furnaces releasing soot in a sudden pressurized release. Residue is extremely fine, oily, and covers every surface in the home — including inside closed cabinets. Requires specialized solvent cleaning. Per IICRC S700 §11.
Ozone generators neutralize odors by oxidation but require unoccupied structures — ozone at effective levels is toxic. Hydroxyl generators use UV light to produce hydroxyl radicals, safe for occupied spaces but slower. Most fire restorations use hydroxyls during occupancy and ozone during final deodorization. Per IICRC S700.
Thermal fogging is a deodorization technique that vaporizes a petroleum-based deodorant at high temperature, producing a fog that penetrates porous materials and recombines with smoke odor molecules. Used on severe fire losses after cleaning but before reconstruction. Structure must be unoccupied. Per IICRC S700.
After any structural fire, the HVAC system acts as a highway for smoke particulate — pulling soot and odors from affected rooms into unaffected zones. Ducts, coils, blower assemblies, and filters must be cleaned or replaced to prevent recontamination after restoration. Per NADCA ACR standard and IICRC S700.
Pyrolysis is thermal decomposition of materials below their ignition temperature, creating discolored heat-affected surfaces without open flame. Often seen on the unexposed side of wall assemblies or ceiling framing. Pyrolyzed wood has reduced structural strength and may require replacement even without visible charring. Per IICRC S700 §10.
IICRC S700 is the industry consensus standard for professional fire and smoke damage restoration. It defines smoke residue classifications, cleaning methods per surface type, deodorization sequence, HVAC decontamination, and documentation requirements. Most U.S. carriers reference S700 for fire claim scope negotiations.
Smoke odor sealing uses pigmented shellac or specialty encapsulants applied to cleaned structural framing and subfloors after fire restoration. Seals residual odor molecules embedded in porous wood that survive cleaning and deodorization. Applied before drywall and finishes are reinstalled. Per IICRC S700.
Wet smoke results from low-heat smoldering fires (typically plastics and rubber) — residue is sticky, smeary, and thick, with severe odor. Dry smoke results from fast-burning high-heat fires (paper, wood) — residue is powdery and easier to clean. Cleaning protocols differ significantly. Per IICRC S700 §10.
Fire suppression water damage is the Category 1 water loss caused by sprinkler discharge or fire department hoses during fire response. Must be extracted and dried alongside fire and smoke remediation to prevent secondary damage. Dual-trade scope — both IICRC S500 water and S700 fire protocols apply.
Contents cleaning after a fire uses four primary methods: dry sponge wiping for loose soot, wet wiping with detergent, ultrasonic immersion cleaning for hard non-porous items, and ozone chamber treatment for fabric and soft goods. Porous items with deep odor saturation are typically disposed rather than restored. Per IICRC S700 §12.
Soot chemistry varies by fuel: synthetic materials burn acidic, leaving residue that corrodes metal and etches glass within days. Natural materials burn more alkaline. Cleaning solution pH must match — acidic residue requires alkaline cleaner, alkaline residue requires acidic cleaner. Wrong pH sets stains permanently. Per IICRC S700 §10.
Dry ice blasting projects pellets of solid CO2 at high velocity against soot-coated surfaces. The pellets sublimate on impact, lifting soot without abrasion or secondary waste. Effective on exposed framing, concrete, and heavy metals in attic and structural fire restoration. Per IICRC S700 §11 cleaning methods.
Structure board-up is emergency installation of plywood over windows and doors destroyed or weakened by fire or fire suppression. Secures the property from weather, theft, and secondary losses during the restoration process. Typically billed as an emergency service under the insurance claim. Industry standard practice per IICRC S700.
Fire damage insurance claims follow HO-3 Coverage A (dwelling) and Coverage C (contents). Process: report loss to carrier, emergency mitigation (board-up, water extraction from suppression), adjuster inspection, scope negotiation with Xactimate line items, mitigation and contents pack-out, reconstruction, final release. ALE covers temporary housing.
