Work Practices
What this domain tests
This domain covers how a sheet metal worker plans, documents, and coordinates work: reading a work order, ordering material, getting a hoisting plan approved, and leaving the job with a clean paper trail. Expect questions on site coordination, load weights, material storage, and environmental responsibility.
Planning and documentation
- A task package usually includes a work order, shop drawings, a material list, a job safety analysis or field-level risk assessment, and permits for hot work, confined space, working at heights, or roof access.
- Approved shop drawings and written instructions govern. When the field conflicts with the drawing, stop and issue an RFI rather than redesigning on your own.
- Record extras as they happen: extra material, extra labour, delay. Undocumented extras are rarely paid.
- Track material by piece mark. Receiving inspection catches damage and gauge substitutions before fabrication starts.
Hoisting and material handling
- Calculate the load before rigging: weight = area x unit weight, plus cleats, hangers, insulation, and rigging.
- Sling capacity drops as the angle from horizontal decreases. Two legs at 45 degrees carry about 71 percent each of the single-leg rating; at 30 degrees, about 50 percent.
- Never stand under a suspended load. Use tag lines, know standard hand signals, and confirm forklift capacity at the actual load centre, not the data-plate maximum.
Storage, shop practice, and environment
- Store sheet on edge on dunnage, not flat on a damp floor. Stacked, unventilated galvanized sheet develops white rust (wet-storage stain).
- Segregate scrap: steel, aluminum, copper, stainless. Mixed scrap has little value, and carbon steel contaminates stainless.
- 5S housekeeping (sort, set, shine, standardize, sustain) keeps a small shop productive and inspection-ready.
Worked example: duct section weight for a lift
A 600 x 400 mm duct, 1500 mm long, 24 ga galvanized at 5.66 kg/m2. Perimeter = 2(0.6 + 0.4) = 2.0 m. Surface = 2.0 x 1.5 = 3.0 m2. Steel weight = 3.0 x 5.66 = 17 kg. Add 20 percent for TDC flanges, corner brackets, and screws: 20.4 kg. Add 3 kg of rigging: about 23 kg per section. A two-leg sling at 45 degrees from a 100 kg single-leg rating holds 2 x 71 = 142 kg, so three sections (69 kg) is a sensible bundle for one lift point.
Traps that cost marks
- Guessing the weight instead of calculating it.
- Forgetting rigging and hardware weight.
- Assuming a forklift lifts its rated capacity at the fork tips.
- Hoisting open-ended duct without cross-breaking it; the section deforms and the seams open.