/ Field knowledge · IMC 801.3
A masonry chimney is not a mechanical-only note.
A masonry chimney cannot be designed on the mechanical sheet alone. IMC 801.3 is short — masonry chimneys are built per the International Building Code (IBC) — and it is one of the highest-value coordination flags in Chapter 8. Correct on M-101 and uncoordinated on A and S still fails review.
Educational 2024 International Mechanical Code (IMC) 801.3 from Daily Code Talk. Confirm the adopted edition. Distinct from liner compatibility (801.15–801.16) and existing reuse (801.18). This is not a chimney design. Packet: 801.3 PDF · ES.
- Location, construction type, structural support, fire-resistance, clearance to combustibles, shaft/enclosure, roof penetration, flashing, liner, cleanout access, and termination height — coordinated across disciplines, not noted once on mechanical.
- Architectural: construction type, fire-resistance rating, roof penetration and flashing. Structural: support and anchorage. Mechanical: liner and connection. All independent of, and consistent with, each other.
- Do not treat a masonry chimney as a mechanical-only note. Do not show “existing chimney to remain” without review criteria.
Put the mechanical vent path next to the architectural and structural details. If construction, liner, cleanout, support, and roof penetration are not all coordinated, the design is not permit-ready.
Existing masonry, “to remain,” no liner, no condition, no clearance
Especially on renovations where the chimney predates the current appliance. Escalate any new appliance on existing masonry, chimneys through fire-rated assemblies or occupied shafts, and roof framing or wall construction that conflicts with the chimney location.
Source: Daily Code Talk — IMC 801.3 · lining: 801.15–801.16 · existing: 801.18 · oil: 801.2.
What to send
Mechanical chimney note, architectural chimney/roof detail if you have it, and whether this is new or existing masonry.
If the chimney is only on the mechanical sheet
Send the M-sheet and the A/S set if you have them. MasterBuild will say whether 801.3 still has no IBC path — or 801.18 still has no four-gate evidence.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
MasterBuild provides engineering services under a written scope. Nothing on this page is project-specific engineering advice, a code interpretation for your project, or a representation about permit approval. Confirm the adopted edition. IBC coordination is 2024 IMC 801.3 education from Daily Code Talk — not a chimney or structural design. This page is not legal advice.