A shot log is a chronological record of every elevation measurement taken on a job — point ID, station/location, instrument used, benchmark reference, design elevation, measured elevation, deviation, and pass/fail. The shot log is your contemporaneous evidence that every required grade check was taken, what the result was, and who took it. It is the primary technical document for grade-related disputes.
Why a Shot Log Matters
Daily reports document what work was done. Shot logs document that the work was done correctly. A daily report might say “installed 175 LF of 8-inch sewer.” The shot log proves every joint was verified at design grade. On DOT projects and municipal utility work, shot logs are a required deliverable — not optional — and the inspector reviews them before signing the pay estimate.
In a dispute, the shot log is often the deciding document. If the shot log shows a failing grade check at STA 8+50 that was not corrected, the owner can point to the date and exact location. If your log shows you re-checked after correction and it passed, you have a defense. If the log has a gap at that station, you have a problem.
What Every Shot Log Entry Must Contain
- Shot number — sequential, unique for the project or phase
- Date and time
- Location — station/offset or GPS coordinates. “NE corner of building pad” is not enough; a coordinate or station+offset is.
- Instrument used — type, model, serial number, and calibration date
- Benchmark reference — which benchmark and its published elevation. Every shot must trace back to a specific, documented benchmark.
- HI (Height of Instrument) for level work, or datum info for GPS work
- Design elevation at the point
- Measured elevation (actual field reading)
- Deviation (measured − design)
- Pass/fail against the project tolerance
- Crew member name
Shot Log Format
| Shot# | Date | Station | Design Elev | Meas. Elev | Dev. | Pass/Fail |
|---|---|---|---|---|---|---|
| 001 | 2026-07-05 | MH-4 invert | 98.50 | 98.50 | 0.00 | ✓ |
| 002 | 2026-07-05 | STA 8+50 | 98.38 | 98.36 | −0.02 | ✓ |
| 003 | 2026-07-05 | STA 9+00 | 98.25 | 98.19 | −0.06 | ✗ Fail |
| 004 | 2026-07-05 | STA 9+00 (recheck) | 98.25 | 98.23 | −0.02 | ✓ |
| 005 | 2026-07-05 | MH-5 invert | 98.00 | 98.01 | +0.01 | ✓ |
Shot Log Conventions
- Never erase or delete: Record failures as failures. An as-built log with a 100% pass rate on a project with known grade issues reads as a curated record. Keep every shot.
- Link retests to failures: When you recheck a failing shot, reference the original shot number. Shot 004 above references Shot 003.
- Log from the field, not from the office: Gradelog’s shot log captures every entry at the moment of measurement, with automatic deviation and pass/fail calculation, GPS location, and instrument tracking.
See also: Daily Field Report Best Practices and Creating an As-Built Document: What Inspectors Actually Need.