Fire rating pattern guide
A legend explaining the different line types used for fire walls, fire barriers, smoke barriers, and fire partitions on architectural plans. Essential for plan review and life safety compliance.
According to NFPA data, fire compartmentalization failures contribute to 23% of fire deaths in commercial buildings. Fire-rated assemblies that are compromised, through incorrect door ratings, missing firestopping, or discontinued barriers, allow fire to spread beyond the compartment of origin. The IBC's prescriptive fire separation requirements are based on over 100 years of fire loss data and are designed to limit fire spread for the expected duration of firefighting response.
Common Line Patterns
Note: Line patterns vary by firm. Always check the project's symbol legend sheet. These are common conventions per NFPA 170.
Fire-Rated Assembly Types
Fire Wall
2-4 HourFire Barrier
1-2 HourFire Partition
1 HourSmoke Barrier
1 HourSmoke Partition
No fire rating requiredDoor & Glass Ratings by Wall Type
| Wall Rating | Door Rating | Glass Rating |
|---|---|---|
| 4-Hour Fire Wall | 3-Hour (A Label) | Not permitted or 3-hr rated |
| 2-Hour Fire Wall/Barrier | 1.5-Hour (B Label) | 1.5-hour rated max |
| 1.5-Hour Fire Barrier | 1-Hour (B Label) | 1-hour rated max |
| 1-Hour Fire Barrier | 45-Minute (C Label) | 45-min rated max |
| 1-Hour Fire Partition | 20-Minute (C Label) | 20-min rated max |
| Smoke Barrier | 20-Minute + S Label | Fire-rated with smoke seal |
Key Rules to Remember
Frequently Asked Questions
A 2-hour fire barrier requires a 1.5-hour (90-minute) fire-rated door assembly, also known as a "B Label" door. The door rating is typically 75% of the wall rating due to how doors are tested. The door must include listed hardware, and vision panels must use fire-rated glazing matching the door assembly rating.
Fire barriers must extend from the floor to the underside of the floor or roof deck above and be securely attached (IBC 707.5). They cannot terminate at a suspended ceiling. Fire walls have even stricter requirements, they must extend through the roof with a parapet or be of noncombustible construction meeting specific criteria. The continuity of fire-rated assemblies is one of the most common code violations.
A smoke barrier (IBC 709) has a 1-hour fire rating and limits smoke migration; doors require smoke and draft control (S Label). A smoke partition (IBC 710) has no fire rating requirement, it only needs to resist smoke passage with tight-fitting construction. Smoke barriers are required in hospitals, detention facilities, and underground buildings for creating refuge areas.
Sources & References
- • International Building Code (IBC) 2021, Chapter 7: Fire and Smoke Protection Features
- • IBC 2021, Section 706: Fire Walls
- • IBC 2021, Section 707: Fire Barriers
- • IBC 2021, Section 708: Fire Partitions
- • IBC 2021, Section 709: Smoke Barriers
- • IBC 2021, Table 716.1: Opening Fire Protection Assemblies, Ratings and Markings
- • NFPA 170: Standard for Fire Safety and Emergency Symbols (2021)
- • NFPA Fire Loss Data: Fires in Health Care Facilities (2023)
Reference based on IBC (International Building Code) and NFPA 170 (Standard for Fire Safety and Emergency Symbols). Always verify requirements with your local Authority Having Jurisdiction (AHJ) and check the project symbol legend.
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