IMC 801.11 is a clean separation rule: a solid-fuel-burning appliance or fireplace cannot connect to a chimney passageway that's already venting another appliance - fuel-fired or otherwise. The rule is simple; tracing an existing chimney to confirm it's actually dedicated is where the review work happens.
Plain-English Highlights
This applies to wood stoves, fireplaces, pellet appliances, coal-burning appliances, and similar solid-fuel equipment. They need their own compliant, dedicated chimney passageway - not a tie-in to a flue already serving a water heater, boiler, furnace, fireplace, or any other combustion appliance. Solid-fuel appliances have different draft behavior, flue gas temperature, soot and creosote potential, and cleaning needs than other fuel types, which is exactly why mixing them in one passageway creates risk.
Permit Proof Chain
Identify every appliance proposed to connect to the chimney passageway -> confirm whether any other appliance currently uses that passageway -> verify the solid-fuel appliance has a dedicated, code-compliant flue -> coordinate liner, connector, cleanout, and termination for that dedicated path -> check for old, unaddressed tie-ins on existing chimneys.
Where To Show It
M-001: solid-fuel appliance venting notes. M-101: appliance location and chimney connection. M-501: dedicated chimney, connector, liner, and termination details. M-601: appliance schedule with chimney/venting basis. A/LS sheets: fireplace, chimney, shaft, roof, and rated assembly coordination. S sheets: masonry chimney support, where applicable.
**Do** - Identify every appliance connected to the chimney passageway being proposed for the solid-fuel unit. - Show a dedicated flue path for the solid-fuel appliance or fireplace. - Coordinate chimney liner, connector, cleanout, and termination requirements for that dedicated path. - Verify existing chimney reuse before approving any connection, including checking for old tie-ins.
**Do Not** - Connect a solid-fuel appliance to a flue that's serving another appliance. - Assume an unused-looking chimney passageway is actually dedicated without verifying it. - Ignore old appliance tie-ins or abandoned openings on the chimney being reused. - Leave solid-fuel chimney coordination to field judgment.
Masterbuild QA Lens
On existing-building projects, 'dedicated chimney' is a claim that needs verification, not an assumption. Trace the full chimney - including any historical tie-ins - before accepting it as compliant for a new solid-fuel appliance.
Drawing / Submittal Check
Confirm the drawings show every appliance connected to the chimney serving the proposed solid-fuel unit - a plan that shows only the new appliance's connection, with no statement about what else (if anything) uses that chimney, is incomplete.
Common Review Risk
The recurring gap is an existing chimney assumed dedicated because only one appliance is currently visible, without checking whether an old tie-in from a removed appliance technically still exists.
When To Escalate
Escalate any solid-fuel appliance proposed for an existing chimney in a building with a history of multiple fuel-fired appliances, and any condition where chimney history can't be confirmed from existing drawings or field investigation.
Field Tip
On existing-building projects, trace the full chimney before signing off on a solid-fuel appliance connection. The permit drawings should clearly show that the chimney passageway is dedicated, not just currently appearing that way.