TinnerFlow™4th YearCoordinationRED · Stop / Verify
A column in a return duct path is not an apprentice-level field modification. Stop, measure the conflict, protect the opening, and get an approved detail before building around structural concrete or steel.
A return duct running into a fixed structural column is a coordination/design issue. Sometimes the recovery may involve rerouting, splitting the duct, enlarging the duct around the obstruction, or building an approved internal shroud, but that decision belongs to the foreman/detailer/engineer.
The apprentice value is to gather clean field information: exact location, duct size, column size, available space on each side, airflow direction, access, and what is downstream. Do not cut, notch, flatten, or freestyle a duct-around-column solution.
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.