IMC 806 closes Chapter 8 with a short section carrying a significant requirement. For metal chimneys, the IMC sends the designer directly to NFPA 211.
IMC 806.1 General
Metal chimneys must be constructed and installed in accordance with NFPA 211. The design cannot stop at labeling a line “metal chimney.” The applicable NFPA 211 requirements become part of the design basis.
What plan review still has to see
Chimney type and application. Materials and construction. Supports and bracing. Clearances to combustibles. Floor, ceiling, and roof penetrations. Termination configuration. Access and inspection provisions. Manufacturer requirements, where applicable.
A reference-standard note is not a drawing
A note reading “per NFPA 211” does not replace the need to show how the chimney is actually routed, supported, protected, and terminated. Whenever the IMC sends you to another standard, treat that standard as part of the code path.
Where to show it
M-001: NFPA 211 design criteria. M-101: chimney routing. M-501: supports, clearances, penetrations, and termination. A sheets: shafts, ceilings, and roof geometry. S sheets: structural support coordination.
Do / Don’t
Do reference NFPA 211, coordinate the full route, show supports and clearances, detail penetrations, and coordinate architectural and structural conditions. Don’t treat “metal chimney” as a complete specification, assume standard duct or vent construction applies, leave supports unresolved, or use “per NFPA 211” as a substitute for coordination.
This completes IMC Chapter 8
Factory-built systems are IMC 805 listed assemblies. Metal chimneys are IMC 806 → NFPA 211. Hub: metal chimneys. Next: Chapter 9 specific appliances, beginning with 901 General.
Project boundary
2024 IMC model-code education. Confirm adopted edition, NFPA 211 edition as referenced, manufacturer instructions, and AHJ path. Not a metal-chimney design.