/ Field knowledge · IMC 607.5.3
“The building is sprinklered” is not 607.5.3.
Ducts and transfer openings that penetrate fire partitions generally need listed fire dampers. “The building is sprinklered” is not an exception. The four 607.5.3 exceptions are useful and they are not casual. Name the wall, the occupancy, the sprinkler status, and which exception — or show the damper.
Educational 2024 International Mechanical Code (IMC) 607.5.3 from Daily Code Talk. Confirm the adopted edition and the IBC assembly type. Distinct from the 607 assembly-first hub. This is not a damper schedule.
- Confirm the wall is a fire partition before applying 607.5.3. A wall labeled fire partition on the architectural life-safety plan with no fire damper on the mechanical set is a coordination failure.
- Exception 1: occupancies other than Group H — fire dampers not required at certain corridor walls in fully sprinklered buildings where the duct is protected as a through-penetration per IBC 714.
- Exception 2: certain mall tenant partitions where those walls are not otherwise required by the IBC to extend to the underside of the structure above.
- Exception 3 (small duct): all seven conditions at once — duct area not more than 100 square inches, minimum steel thickness, no corridor-to-room openings, above ceiling, no wall-register termination, steel sleeve and retaining angles, mineral wool at the annular space. Missing even one disqualifies it. A duct that meets the area limit but terminates with a wall register, or has a corridor opening, is out.
- Exception 4: ducted HVAC through a fire partition rated 1 hour or less in a non-Group H area of a fully sprinklered building — minimum 26 gage sheet steel and a continuous ducted system from equipment to air terminals.
On the set: which exception, if any. For Exception 3, show all seven conditions — not just the duct area. For Exception 4: gage, barrier rating, occupancy, and sprinkler confirmation on M-001.
No damper because “it’s sprinklered”
Escalate Group H corridors (no exceptions), buildings without the full sprinkler coverage Exceptions 1 or 4 need, and Exception 3 claims that physically cannot meet all seven conditions.
Source: Daily Code Talk — IMC 607.5.3 · tool: Fire-partition screen · 607: name the assembly · corridors: 607.5.4 · shafts: 607.5.5 · 601.3: exit enclosures.
What to send
Life-safety plan with fire partitions marked, the duct plan at those walls, occupancy (including any Group H), and whether the building is fully sprinklered.
If the damper was omitted because the building is sprinklered
Send the rated plan and the duct. Masterbuild will say whether 607.5.3 still has no named exception — or Exception 3 still has a wall register that kills the seven-condition path.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
Masterbuild provides engineering services under a written scope. Nothing on this page is project-specific engineering advice, a code interpretation for your project, or a representation about permit approval. Confirm the adopted edition. The four exceptions, 100 square inches, 26 gage, and seven-condition small-duct path are 2024 IMC 607.5.3 education from Daily Code Talk — not a damper schedule. This page is not legal advice.