Before You Reroute

Use this when duct does not fit and you are tempted to offset, jog, lower, raise, reduce, or move the run.

A duct route is blocked by structure, sprinkler, pipe, cable tray, framing, ceiling, access requirement, or another trade.

Always ask when a reroute changes size, elevation, fitting, damper location, access, support, pressure class, or coordination with another trade.

Do not reduce duct size without approval.
Do not add random offsets that create airflow/TAB problems.
Do not move fire/smoke dampers or access doors casually.
Do not lower duct into ceiling conflicts without checking finished ceiling and access.

Do not reroute first. Document the conflict and ask for direction.
Identify the obstruction and whether it is structure, another trade, ceiling/framing, equipment, access, or print mismatch.
Compare field condition to latest print/shop drawing.
Measure how much clearance is missing and where the obstruction starts/ends.
Check if the reroute would affect duct size, slope, access doors, dampers, hangers, insulation, ceiling height, or TAB.
Take clear photos with measurement reference.
Tell the foreman the exact conflict: what duct, where, what blocks it, how much clearance is missing, and what options might exist.