IMC 801.1 opens Chapter 8 with a plan-review boundary, not a technical requirement: what venting system is being reviewed, and which code actually governs it. Get that wrong and every downstream decision - vent material, sizing, clearance, termination - is reviewed against the wrong standard.
Plain-English Highlights
Section 801.1 puts four things inside Chapter 8: factory-built chimneys, chimney liners, vents, and vent connectors, plus the utilization of masonry chimneys - covering installation, maintenance, repair, and approval. It draws one hard line: gas-fired appliances vent under the International Fuel Gas Code (IFGC), not directly through Chapter 8. Before reviewing any vent detail, confirm appliance type and fuel type first.
Permit Proof Chain
Appliance and fuel type -> governing venting standard (IMC 801, NFPA 31, or IFGC) -> chimney/vent/connector/liner classification -> Section 804 check for direct-vent or mechanical-draft systems -> downstream sizing, clearance, and termination review.
Where To Show It
M-001: chimney/vent notes, code criteria, and appliance venting basis. M-101: equipment layout, vent route, and chimney/vent locations. M-501: chimney, liner, vent, connector, support, penetration, and termination details. M-601: appliance, boiler, furnace, water heater, and generator schedules. A/LS sheets: masonry chimneys, shafts, rated walls, roof assemblies. P sheets: fuel, oil, boiler, and water heater coordination. E sheets: draft fans, exhausters, interlocks, controls.
**Do** - Identify the appliance and fuel type before selecting a venting method. - State the governing venting standard on the drawings. - Distinguish chimney, vent, connector, and liner - they are not interchangeable terms. - Check Section 804 before assuming a direct-vent or mechanical-draft appliance falls outside Chapter 8.
**Do Not** - Apply IMC Chapter 8 to gas-fired appliance venting without checking the IFGC. - Use "existing chimney to remain" without defining the review path. - Leave the governing venting code to field interpretation.
Masterbuild QA Lens
Scope errors are the most expensive mistake in Chapter 8 review because they're invisible until someone checks the fuel type. A vent detail can be perfectly drawn and still wrong if it was reviewed against IMC 801 when the appliance is gas-fired and should have gone through the IFGC.
Drawing / Submittal Check
Cross-check the appliance schedule against every vent detail on the drawings: does each appliance's fuel type match the code path cited in the note, and does the cited standard (IMC 801, NFPA 31, IFGC) actually govern that fuel type?
Common Review Risk
Reviewers most often catch this when a vent connector is mislabeled as a chimney, or when a direct-vent appliance is detailed under the full prescriptive Chapter 8 path instead of being checked against Section 804 first.
When To Escalate
Escalate mixed-fuel mechanical rooms (gas and oil-fired appliances sharing a space), any appliance where the listing doesn't clearly state its venting category, and projects converting an existing gas appliance to oil or solid fuel.
Field Tip
Before opening the vent detail, open the appliance schedule. If fuel type, venting method, and governing standard aren't listed there, the design is incomplete - not just under-detailed.