Content Gap Batch 9

Black-Iron Duct Basics Before Fabrication or Install

Grease Duct, Kitchen Exhaust & Industrial ExhaustSTOP / VERIFYField judgment

Core Answer

Confirm the duct’s listed or code-driven construction, weld, access, clearance, slope, and inspection requirements before treating black iron like ordinary exhaust duct.

Open in Field Rescue Open Category

What to Check First

Identify the exact exhaust system
Review current approved drawings and welding requirements
Confirm material thickness and joint method
Locate cleanouts and access
Verify clearance or enclosure requirements before install

Ask Foreman

This black-iron run serves [system]. Which approved construction, weld, access, and clearance details control before we fabricate or set it?

Text to Foreman

Do Not Do This

Do not substitute ordinary duct methods, intermittent welds, unapproved access doors, or field changes in a grease or hazardous exhaust system.

Why This Matters

Black iron is used in systems where leakage, grease, heat, chemicals, or fire exposure can create severe hazards.

Verify against: approved drawings/specifications, applicable code/listing, welding procedure, AHJ/foreman direction.