Building Construction and Fire Protection Systems
Construction types
Know the five NFPA types: I fire-resistive, II noncombustible, III ordinary (masonry exterior walls, combustible interior), IV heavy timber, and V wood frame. Then overlay the distinction that actually kills firefighters: legacy construction with full-dimension lumber versus modern lightweight construction using engineered wood I-joists, trusses, and gusset plates. Lightweight assemblies fail early and often without warning. Balloon framing permits fire travel inside wall voids from basement to attic; platform framing blocks it at each floor.
Built-in protection
Expect questions on sprinkler systems (wet, dry, preaction, deluge), standpipe classes (Class I 2½-inch for fire department use, Class II 1½-inch for occupants, Class III both), fire department connections, risers, OS&Y and post indicator valves, water-flow and tamper switches, fire pumps, and detection choices between ionization and photoelectric smoke detectors. Identify the alarm valve and where to connect before you need them.
Traps
Dry pipe systems hold air that keeps water back until a head fuses; deluge systems have open heads. A common distractor describes a preaction system as a deluge. Another asks what to do when sprinklers are operating - the answer is to support them and let them work, shutting down only on the incident commander's order.
Rule of thumb
Size-up asks three questions for every building: what is it made of, what loads are on it, and where will fire and smoke travel?