Observed principle 1
Buoyancy and pressure differences can move smoke through vertical pathways.
Smoke Authority · Guide 16
Smoke Movement in Multi-Story Buildings
Why shafts, stairwells and stack effect can move smoke vertically.
Primary sources first
What authoritative public sources establish
Observed principle 2
Elevator shafts, stairs and utility chases can connect remote areas.
Observed principle 3
Deposition patterns should be verified floor by floor.
Source boundary: This page summarizes public technical guidance. It does not reproduce proprietary restoration standards, insurer estimating systems, or licensed-professional conclusions.
SDM Intelligence interpretation
How this applies to vertical smoke movement
For a vertical smoke movement question, SDM Intelligence treats the incident as a set of observable conditions rather than assuming every room or material needs the same treatment. The practical objective is to identify the source, determine the pathways that spread the condition, separate cleanable material from physically damaged or inaccessible material, and document why each action is taken.
Field step 1
Inspect vertical pathways and door/shaft interfaces.
Field step 2
Compare residue above and below the fire floor.
Field step 3
Coordinate with building engineers when pressure-control systems are involved.
Decision sequence
A practical order of operations
1. Safety and access. Confirm that the area can be entered and that utilities, structure, contamination and occupancy restrictions are understood.
2. Evidence before disturbance. Photograph the affected area, note pathways and limits of access, and collect measurements that are appropriate to the condition.
3. Source control. Remove or control the material or condition that is continuing to generate damage, particles, moisture or odor.
4. Cleaning / drying / removal. Choose the least destructive method that can reliably reach the affected material and produce a defensible outcome.
5. Verification. Reinspect the original source areas and hidden pathways before reconstruction or turnover.
Unknowns and professional boundaries
What still requires property-specific evidence
The sources above establish general principles, not the condition of a particular building. They do not tell us the temperature a specific assembly reached, the chemical composition of residue at your property, the structural capacity of a damaged member, or whether a specific material can be safely retained without inspection. Those conclusions require site evidence and, where appropriate, a licensed or qualified specialist.
Immediate life-safety, structural, electrical, medical, industrial-hygiene, code and other regulated questions should be directed to the appropriate authority or licensed professional.
Direct sources
Primary supporting references
- NIST — Building Fire Safety Evaluation
- EPA — Wildfires and Indoor Air Quality in Schools and Commercial Buildings
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