--- title: "Factors for limiting fire spread" subject: "Building Technology" chapter: 12 key: "semester_6/building_technology:fire-spread-factors" source: https://www.bctengineer.com/q/semester_6/building_technology/fire-spread-factors site: BCT Engineering --- # Factors for limiting fire spread Building Technology · Chapter 12: Other services in building - Asked in: 2070 Bhadra, 2+6 marks - Video: [Passive Fire Protection System | Complete Fire Protection Engineering Explained](https://www.youtube.com/watch?v=OoQtGqDzav4) — Sajjad Ansari MEP - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_6/building_technology/fire-spread-factors - Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-12 ## Question What are the factors to be considered for limiting fire spread? Clarify each point briefly. ## Short answer To limit fire spread, use non-combustible materials, compartmentalise with fire-rated walls/floors, protect openings with fire doors/stops, control vertical spread via enclosed shafts and spandrels, maintain separation between buildings, ensure structural fire resistance, and instal detection/sprinkler systems with good housekeeping. ## Answer Fire spreads by conduction, convection and radiation, and through openings. The factors to consider to limit it are: 1. **Choice of materials:** use non-combustible and fire-resistant materials (brick, concrete, stone, fire-rated boards) for walls, floors, roofs and finishes; avoid highly combustible linings and furnishings. 2. **Compartmentation:** subdivide the building into fire compartments with fire walls and floors of rated resistance, so that fire stays in the room of origin. 3. **Protection of openings:** fire doors, fire shutters, and fire-rated glazing; sealing of pipe and duct penetrations with fire stops. 4. **Vertical spread control:** enclosed fire-resisting stairs, lift shafts and service ducts; spandrel beams or projections between windows to stop flames climbing the facade; fire dampers in ducts. 5. **Separation between buildings:** adequate distance and fire-resisting external walls to stop radiation and ignition of neighbours. 6. **Fire resistance of structure:** adequate concrete cover to rebars, protection of steel by encasement, plaster or intumescent paint. 7. **Surface spread of flame:** use finishes with low flame-spread rating on walls and ceilings. 8. **Smoke control and ventilation:** vents, smoke curtains and pressurised stairs. 9. **Detection and fighting systems:** early detection, sprinklers and hydrants to put out fire quickly. 10. **Good housekeeping and wiring:** proper electrical installation, and safe storage of flammable materials. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. Which choice of materials best limits fire spread? A. Non-combustible, fire-resistant materials such as brick, concrete, stone and fire-rated boards B. Highly combustible linings for easy replacement C. Plastic furnishings throughout D. Timber for all walls and floors Answer: A. Non-combustible and fire-resistant materials for walls, floors, roofs and finishes limit how fast fire spreads. (Key point: Material choice) 2. What does compartmentation achieve? A. It makes the fire spread faster to every room B. It confines fire to the room of origin using fire walls and floors of rated resistance C. It replaces the need for fire doors D. It increases the fuel load Answer: B. Fire compartments with rated walls and floors keep the fire in the room where it started. (Key point: Compartmentation) 3. How is vertical spread of fire up the facade controlled? A. By leaving open service shafts B. By removing all windows' sills C. By spandrel beams or projections between windows, enclosed stairs, lift shafts and ducts, and fire dampers D. By using flammable cladding Answer: C. Spandrel beams stop flames climbing the facade, and enclosed stairs, shafts and dampers block vertical paths. (Key point: Vertical spread) 4. Why is adequate separation between buildings provided? A. To stop radiation and ignition of neighbouring buildings B. To increase conduction through the soil C. To help fire to jump between buildings D. To reduce the plot area Answer: A. Distance and fire-resisting external walls stop radiant heat from igniting adjacent buildings. 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