Estimating, Documentation, and Quality Control
What this domain tests
This domain tests whether you can take off quantities, apply waste and labor, document changes, and verify that the installed work meets the specification.
Core rules
- Take off by system and size: linear feet of pipe, number of fittings and valves, square feet of duct and equipment, and each removable cover.
- Add waste for cuts and fittings; common allowances are 5–10% for pipe insulation and more for complex fittings. Use the job standard if one is specified.
- Labor units are applied per item or per length; access, height, and confinement change productivity. Document these conditions.
- Record RFIs, addenda, and field changes in daily reports and as-built documents.
- QC checks include thickness, material type, joint tightness, securement spacing, vapor-retarder continuity, jacket laps, and firestopping. Nonconformance needs a corrective action and re-inspection.
- Do not cover work before inspection if the specification requires a hold point.
Worked example
Estimate 100 linear feet of 4-inch pipe with 1½-inch insulation. The pipe takeoff is 100 ft. Add four 90° elbows and two valves as separate items. With 10% waste, order 110 ft of pipe covering plus fittings. If the job uses 0.2 labor hours per foot, the base labor is 20 hours, before adding fittings and access. The reasoning: fittings and waste are not included in the straight-pipe length, and labor must match the actual installation.
Traps
Forgetting valves and fittings; using the wrong unit, square feet versus linear feet; omitting waste; ignoring access and scaffolding; and documenting only at the end of the job.