TinnerFlow™3rd YearGrease DuctRED · Stop / Verify
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.
Grease duct is not normal comfort-air duct. If a horizontal grease run is hung flat when the approved design requires slope or drainage, grease can pool in low spots and turn the install into a fire/inspection problem.
Do not guess the slope number from memory. Check the mechanical drawings, grease duct detail, hood/exhaust submittals, code/AHJ requirement, and foreman direction. Then adjust supports/elevations before the run is welded, wrapped, or made hard to access.
Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.