Chapter 7 covers the rated assemblies that compartmentalize a building so fire and smoke don't spread freely: fire walls (706), fire barriers (707), fire partitions (708), smoke barriers (709), and horizontal assemblies (711). It also governs how you keep those assemblies intact where things pass through them — opening protectives like rated doors and glazing (716) and firestopping at through-penetrations and joints (714, 715).
Ratings are in hours, and the key idea is continuity: a rated wall only works if it runs unbroken, typically full height to the deck, with every opening and penetration protected to match.
The common mistake is showing a rated line on the life-safety plan and then breaking it — an unrated door in a rated corridor wall, a duct or pipe penetration without a firestop, or a wall stopped at the ceiling instead of the deck. Reviewers trace each rated assembly for continuity and confirm openings and penetrations carry the right protection.
This guide describes the model code for general understanding and is not a substitute for the adopted code and amendments enforced by your local authority having jurisdiction. Verify all figures against your jurisdiction's codes of record.