Building Construction and Fire Protection Features
Types of construction and compartmentation
Know the five construction types (I through V) and that Type I/II are noncombustible and generally more fire-resistive, Type III is exterior noncombustible with combustible interior, Type IV is heavy timber, and Type V is wood frame. The code uses fire-resistance ratings (hours) to separate occupancies and limit spread. Compartmentation - rated walls, floors, and horizontal assemblies - buys time for egress and suppression.
Openings and penetrations
A tested area is protection of openings: fire doors, fire shutters, and fire dampers in ducts that penetrate rated assemblies. Questions often ask what protects a penetration through a rated wall - the answer is a listed firestop system, not just any sealant. Fire doors must be self-closing and latching, and must not be propped open unless held by a listed release device tied to the alarm.
Worked rule of thumb
When given a scenario with a rated wall, ask three questions: (1) what is the required hourly rating, (2) what opening protection is required, and (3) is the opening held open only by an approved automatic-closing device? If the door is wedged, the rating is defeated regardless of the wall's rating.
Traps
Don't confuse fire-resistance rating (assembly performance in hours) with flame-spread or smoke-developed index (interior finish, covered in the egress domain). Also, a higher construction type number does not mean more protection - Type V is the least fire-resistive.