Playbook
Before You Cut
Use this before cutting duct, sheet metal, flex, insulation, roof/wall openings, or field holes.
What this covers
You are about to cut something and the cut affects duct size, route, access, rated assemblies, roof/wall penetrations, insulation, or a finished/exposed surface.
How to use this playbook
- Stop and confirm what you are cutting, why it needs to be cut, and who approved the cut.
- Match the location to the latest drawing/shop drawing.
- Measure twice from a real control point, not from memory.
- Confirm system, duct size, airflow direction, and what is behind/above/below the cut.
- Look for dampers, access doors, insulation, liner, wiring, controls, sprinkler, structure, and rated assemblies.
- Take a wide photo, close photo, and a photo showing the measurement/reference point.
- Ask the foreman/journeyman before cutting if the cut changes route, size, access, support, rating, slope, or manufacturer detail.
Check
- Wide context photo
- Close-up of cut area
- Tape measure/reference photo
- Photo of conflict or reason for cut
Warnings
- Do not cut because 'it looks close enough.'
- Do not cut a damper/access/grease/rated area without direction.
- Do not make a field opening that blocks service/TAB/inspection access.
- Do not cut blind into walls, decks, roofs, shafts, or unknown ceiling spaces.
Stop and ask
- Ask before cutting if the print does not match field, another trade blocks the route, the cut touches a rated assembly, the duct is grease/exhaust/industrial, or the cut changes the intended fitting.