/ Field knowledge · IMC 510.2
Over 600°F is not just another exhaust outlet.
If the exhaust is over 600°F, it is not “just another outlet.” IMC 510.2: outlets exceeding 600°F (315°C) are designed as a chimney per Table 510.2 (single-wall metal chimneys). Minimum wall thickness in all categories: 0.127 in (No. 10 MSG). Termination height, lining, and clearance follow the appliance heat class — high (over 2,000°F), medium (2,000°F max), or low (1,000°F normal). A 10-ft grease-fan typical is the wrong sheet.
Educational 2024 International Mechanical Code (IMC) 510.2 from Daily Code Talk. Confirm the adopted edition. Distinct from 510 dust conveying, 510.1.5 explosion, and IMC 805 medium-heat factory-built. This is not a chimney design.
- All categories: minimum wall thickness 0.127 in (No. 10 MSG).
- High-heat (over 2,000°F): lining 4½ in laid on a 4½ in bed. Terminate 20 ft above the roof opening, and 20 ft above any part of a building within 50 ft. Clearance: per the design engineer — combustibles not exceeding 160°F.
- Medium-heat (2,000°F max): lining up to 18 in diameter = 2½ in; over 18 in = 4½ in on a 4½ in bed. Terminate 10 ft above the roof opening, and 10 ft above any part of a building within 25 ft. Clearance to combustibles: 36 in interior, 24 in exterior.
- Low-heat (1,000°F normal): no lining. Terminate 3 ft above the roof opening, and 2 ft above any part of a building within 10 ft. Clearance to combustibles: 18 in interior, 6 in exterior. Clearance to noncombustibles: 2 in up to 18 in diameter, 4 in over 18 in.
- Lining generally extends bottom to top of the outlet. For the noted condition: lining extends 24 in below the connector to 24 ft above.
A 600°F+ process stack detailed like a kitchen upblast
Or “terminate per manufacturer” with no Table 510.2 class. Heat class first — then thickness, lining, height, and clearance.
Source: Daily Code Talk — IMC 510.2 · tool: Heat-class screen · 510: dust conveying · 805: factory-built medium-heat.
What to send
The exhaust temperature at the outlet (or the process that sets it), whether a heat class is named on the drawings, and the proposed termination height and clearance.
If the stack is over 600°F and detailed like a kitchen fan
Send the temperature. Masterbuild will say whether 510.2 still has no Table 510.2 class — or 510.2 still has a 3-ft termination on a medium-heat appliance.
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. 600°F, 0.127 in (No. 10 MSG), Table 510.2 high/medium/low heights and linings, and 160°F combustible limit are 2024 IMC 510.2 education from Daily Code Talk — not a chimney design. This page is not legal advice.