Static field route #18807

What do I do when grease duct is being hung level and may need slope?

Grease Duct, Kitchen Exhaust & Industrial Exhaust🚨 STOP / VERIFYV188 answer-gap expansion

📖 Verified core answer

Stop before the grease duct gets welded, wrapped, or closed in as a flat run. Verify the approved grease duct detail, slope direction, cleanout/drain requirements, and support elevation before continuing.

Open in Field Rescue Open category

Field verification checklist

Confirm system is kitchen exhaust/grease duct, not normal exhaust.
Check the approved detail for slope direction, cleanout, drain/reservoir, access, weld/seal, and support requirements.
Measure start and end elevations before final welding/wrap/inspection.
Look for low spots where grease could collect.
Document any section already hung level before moving forward.

Ask foreman

The grease duct run at [location] is being hung level/backpitched. I checked the detail and it looks like slope/drainage needs verification before we continue. Do you want me to hold and reset the hanger elevations per approved direction?

Text to foreman

Route options

AMake the small field correction only if it is within your assignment and the approved method.

BHold and document the condition if the fix affects airflow, access, life safety, pressure class, rated assemblies, equipment, or another trade.

CBring the foreman/detailer the location, what you checked, and what decision you need before cover, startup, or rework.

Do not do this

Do not leave a grease duct run flat, backpitched, or with a belly because it “looks close enough.”

Why this matters

Grease pooling is a life-safety and inspection issue. Fixing slope after welding, fire wrap, or ceiling close can be expensive and ugly.

Verification basis

Approved drawings/specs, project coordination drawings, manufacturer instructions/submittals, shop standards, foreman/detailer direction, employer policy, and AHJ/code requirements.