/ Field knowledge · IMC 805
A line labeled “chimney” is not a listed system.
Factory-built chimneys are listed assemblies from appliance connection to termination. Diameter is the last decision, not the first.
Educational 2024 IMC 805 from Daily Code Talk. Confirm adopted edition, listing, and manufacturer instructions. Packet: 805 PDF · ES.
- 805.1–805.3. Listed and labeled. Match appliance and fuel. UL 103 Type HT where required for dwelling-unit solid-fuel. UL 127 for factory-built fireplaces. Do not mix incompatible components.
- 805.4 / 805.5. Offsets: maximum 30° from vertical, maximum four elbows. Structural members that support the chimney must be designed for the added load.
- 805.6. Flue-gas temperature over 1,000°F at the chimney entrance → UL 959. Entrance temperature, not just input or pipe size.
- 805.7. Decorative shrouds only if listed for that system.
- 805.8. Insulation shield; code-built path uses minimum No. 26 gage steel; attic shield at least 2 in above insulation; secured against displacement.
Source: 805 recap · metal: IMC 806 / NFPA 211 · shrouds: 805.7 · offsets: 805.4–805.5 · tool: chimney pathfinder.
Free sample — the four-gate existing-chimney acceptance
“Existing chimney to remain” is the most expensive four words on a renovation mechanical set. The complete acceptance section from the IMC 2024 Chapter 8 Chimneys and Vents Field Guide — all four gates, the survey discipline, the escalation trigger, and the record it produces — is available as a free PDF. No email required. Download the sample (PDF). The full edition is available in the Field Guides catalog.
If the set only says “chimney”
Send the appliance listing, the routing, and whether this is factory-built or metal. MasterBuild will say whether 805 or 806 is even on the path.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
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