IBC 717.5.7
Smoke dampers in smoke partitions (IBC 717.5.7)
Smoke partitions are not required to be fire-resistance rated unless another section requires it. They need smoke dampers only at air transfer openings, such as transfer grilles, not where a duct passes through.
What counts as a smoke partition: A wall that limits smoke movement but is not fire-resistance rated, such as some corridor walls in Group I-2.
Rules last reviewed October 12, 2026. How the rules are checked
Check your case in the tool (2024 IBC)Start the tool with the 2021 IBC · Start the tool with the 2018 IBC
When each damper is required
Every result the tool can give for a duct carrying heating, cooling or ventilation air, or an air transfer opening, through this assembly. Labels show where a result applies only to ducts, only to air transfer openings, or only in some editions.
Smoke damper
- RequiredAir transfer openings only
Air transfer openings in smoke partitions need a listed smoke damper.
IBC 717.5.7, IBC 710.8
- Alternative protectionAir transfer openings only
A smoke damper would interfere with a required smoke control system, so approved alternative protection must be used instead.
IBC 717.5.7 Exception, IBC 710.8 Exception
- Not requiredDucts only
Smoke partitions need smoke dampers only at air transfer openings, not at ducts.
IBC 717.5.7, IBC 710.8
Also required
- Fill the space around the duct with an approved material to limit the passage of smoke. (ducts only) IBC 710.8
- Flexible air connectors may not go through any wall, floor or ceiling at all. (ducts only) IBC 717.7
Common situations by edition
| Situation | 2024 IBC | 2021 IBC | 2018 IBC |
|---|---|---|---|
| Duct through a smoke partition | No damper required | No damper required | No damper required |
| Transfer grille in a smoke partition | Smoke damper required | Smoke damper required | Smoke damper required |
| Transfer grille where a damper would interfere with a required smoke control system | Approved alternative protection required | Approved alternative protection required | Approved alternative protection required |
Select a result to open it in the tool with every answer filled in, including the conditions not listed here.
Exceptions and conditions the tool checks
The tool asks no further questions for a duct through this assembly. For an air transfer opening it asks one:
Would a damper in this opening interfere with how a required smoke control system operates?
Engineered smoke control systems (IBC 909) sometimes need ducts or openings to stay open during a fire. The smoke control design must show this.
IBC 909, IBC 717.2.1
Questions
Do ducts through a smoke partition need smoke dampers?
No.
Smoke damper: not requiredAll three editions
Smoke damper: not required. Smoke partitions need smoke dampers only at air transfer openings, not at ducts. IBC 717.5.7, IBC 710.8
Also: Fill the space around the duct with an approved material to limit the passage of smoke. IBC 710.8
Full result in the tool: No damper required
Do transfer grilles in a smoke partition need smoke dampers?
Yes, unless a damper would interfere with a required smoke control system.
Smoke damper: requiredAll three editions
Smoke damper: required. Air transfer openings in smoke partitions need a listed smoke damper. IBC 717.5.7, IBC 710.8
Full result in the tool: Smoke damper required
What if a smoke damper would interfere with smoke control?
Smoke damper: alternative protectionAll three editions
Smoke damper: alternative protection. A smoke damper would interfere with a required smoke control system, so approved alternative protection must be used instead. IBC 717.5.7 Exception, IBC 710.8 Exception
Full result in the tool: Approved alternative protection required