IMC 801.2 is the rule everything else in Chapter 8 builds on: combustion products need an approved path out of the building, and that path has to be sized and selected for the specific appliance connected to it - not assumed from whatever chimney happens to be nearby.
Plain-English Highlights
Every fuel-burning appliance must discharge to a vent, factory-built chimney, or masonry chimney, unless it's vented under Section 804 (direct-vent, integral-vent, or mechanical draft). Commercial cooking appliances under a Type I hood are reviewed under IMC 507, not as appliance venting here. Section 801.2.1 adds that oil-fired appliances must also coordinate with NFPA 31 - which controls chimney sizing, draft, combustion temperature, liner compatibility, and blocked-vent protection for oil equipment specifically.
Permit Proof Chain
Appliance type and fuel -> Section 804 check (direct-vent/integral-vent/mechanical draft exception) -> chimney or vent selection matched to the appliance listing -> NFPA 31 coordination if oil-fired -> vent size, material, and termination shown on the drawings.
Where To Show It
M-001: chimney/vent design criteria and appliance venting notes. M-101: equipment layout and vent route. M-501: vent, chimney, connector, penetration, and termination details. M-601: appliance schedule with fuel type and venting method. P sheets: oil piping, fuel piping, boiler, and water heater coordination. A/LS sheets: shafts, rated assemblies, roofs, exterior openings. E sheets: powered exhausters, interlocks, controls.
**Do** - Match the venting method to the appliance listing, not to what's convenient to route. - Identify whether the system is natural draft, direct vent, integral vent, or mechanical draft. - Coordinate every oil-fired appliance with NFPA 31. - Show the full combustion-product path from appliance outlet to termination.
**Do Not** - Use "vent to exterior" as a complete design note. - Assume an existing masonry chimney is acceptable for a new appliance without review. - Confuse Type I hood exhaust with appliance venting under Section 801. - Leave oil-fired venting details to the installer without a reviewable basis.
Masterbuild QA Lens
801.2 is where 'vented' and 'vented correctly' diverge. Confirm the appliance listing names the venting category before accepting any chimney or vent on the drawings - the listing controls, not the available chimney.
Drawing / Submittal Check
For oil-fired equipment specifically, verify the drawings or specifications reference NFPA 31 by name and address chimney sizing, draft requirement, and blocked-vent protection - a generic 'per code' note isn't sufficient for oil appliances.
Common Review Risk
The most common gap is an oil-fired appliance detailed with only an IMC 801 note and no NFPA 31 reference - sizing and draft requirements differ enough between the two that omitting NFPA 31 coordination is a real technical gap, not paperwork.
When To Escalate
Escalate any oil-fired appliance connected to an existing chimney without a documented condition and liner assessment, and any project where a Type I hood exhaust is being confused with or substituted for appliance venting.
Field Tip
Add a venting column to the appliance schedule with fuel type, venting method, vent material, and governing standard. If that column is blank for any appliance, the design isn't permit-ready.