8.3 Construction Staking Field Practice

What construction staking is on this exam

Domain III, activity 6 is perform construction staking. Knowledge item C is interpretation of elements in construction plans and specifications pertaining to staking. Item P is field practices and procedures for construction staking. Item M returns as field notes and staking reports. You are translating a designed station, offset, and grade onto the ground from the same control used for topography and layout—not retracing a PLSS corner and not taking soundings.

Interpreting plans and specifications before the first hub

Open the control sheet, typical details, and the sheet that shows the feature:

1. Basis of bearings and CCS — zone, realization, epoch. If the grading sheet is silent, the project control sheet still governs. Do not assume an assumed site origin when the control sheet names CCS83 Zone 5 epoch 2017.50.
2. Benchmark — occupy the named vertical datum. A chewed-up blue-top is not the benchmark.
3. Stationing line — which line the stations are on (construction centerline, curb return, pipe). Station 12+50 on the “A” line is not 12+50 on a ramp.
4. Offset and the feature — 24.00 ft right to face of curb is not 24.00 ft to lip of gutter or to a 2.00 ft offset hub unless the spec or request says so.
5. Grade call — invert, flow line, top of curb, hinge, finished subgrade. Specs and details name the surface. Staking the wrong surface by 0.50 ft is a reading error, not a GNSS error.
6. Units and grid/ground — apply the combination factor the plans use if you are converting CCS83 grid to the ground distances the contractor will tape.
7. Conflicts — Caltrans Chapter 12 tells Surveys to check planned lines and grades against existing pavement conforms, curb joins, and drainage inlets/outlets, then tell the Resident Engineer (RE). That check is field interpretation, not redesign by stealth.

If the request is ambiguous (“stake the curb”), stop and get the feature, station limits, and original-versus-reset in writing.

Public-works workflow (Caltrans as a California model)

Caltrans Surveys Manual Chapter 12, Construction Surveys (November 2012 PDF posted by the Department) and Standard Specifications 5-1.26 describe a repeatable pattern many California agencies echo:

• The contractor does not send a text to a rover operator. Staking requests go on Form DPD-3013 (or equivalent digital request). Older construction-manual language also cites DOT SUR-102; treat those as the same kind of written request. The contractor lists priority, type (slope, curb, drainage), original versus reset, location/stations, and date needed. The RE signs; Surveys accepts requests from the RE, not from whoever is holding a radio.
• The Party Chief does not stake an unprepared area. If the grade is not ready, notify the RE.
• Surveys begins staking within 2 business days of a complete request (Chapter 12 and 5-1.26). That clock is a Caltrans specification, not a Board-wide PLS statute, but it is the California public-works number the exam can reasonably use.
• When staking is finished, the Party Chief completes the request form. Electronic stakeout reports, listings with actual staked positions, or equivalent notes are filed with the Resident Engineer. The RE can copy the contractor.
• Restaking of destroyed original stakes is recorded as restaking; Chapter 12 routes cost questions through the RE.
• Automated machine guidance (AMG) does not erase control. The contractor still constrains to provided local survey control; Surveys verifies those points and reviews the calibration report. Stake density may drop when AMG is used; datum consistency must not.

Private commercial jobs may skip the DPD-3013 number and still need the same pieces: written scope, named control, as-staked report, and a person who can authorize restake charges.

Worked example: cut-sheet contents

Request: original curb stakes, “A” line Stations 12+00 to 13+00, face of curb, 24.00 ft right, NAVD 88, CCS83 Zone 5 epoch 2017.50.

You occupy CP-4, backsight CP-5, check CP-6. Check residual: 0.02 ft horizontal, 0.01 ft vertical. Good enough to stake curb.

At Station 12+50.00, design face-of-curb elevation is 318.45 ft. You set a hub/ginnie at a convenient offset mark whose elevation is 320.12 ft. Cut from hub to face of curb = 320.12 − 318.45 = 1.67 ft. As-staked station/offset of the hub is 12+50.03, 24.04 ft Rt—within a 0.03 ft hub-head tolerance Caltrans illustrates for a 1×1 in ginnie (0.06 ft head).

What does not belong: the contractor’s shouted “cut a foot and a half”; a PLSS township; rewriting design 318.45 to 320.12; omitting the occupied control. The cut sheet is a staking report. Another licensee should be able to put a rod on the hub and recover the same 1.67 ft cut.

Slope-stake reports add catch-point station/offset, slope ratio (for example 2:1), and cut/fill to hinge. Caltrans spaces typical slope stakes 100 ft, tightening to 50 ft when stakes must see each other, on curves with radius less than 1,000 ft, or when cuts/fills exceed 10 ft. Those spacings are Chapter 12, not a Board table.

Marking, colors, and tolerances

Chapter 12 marking practice (Department plastic cards; Party Chief may simplify on wood lath):

• Distances, elevations, and cuts/fills to 0.01 ft, except slope stakes, abutment-fill stakes, and rough-grade stakes at 0.1 ft.
• Stationing-line name and station on the stake; cuts/fills measured from the reference point (hub) to the feature.
• Color codes (flagging/cards): horizontal and vertical control white/red; grading (slope, rough, final) yellow; structures white; drainage (pipes, inlets, curbs, gutters in that table) blue; right-of-way/fence white/yellow; miscellaneous (signs, barrier, lighting) orange. Private sites may use other colors; the exam still expects you to know that color is a communication system, not decoration.

Tolerance versus accuracy: Chapter 12 says a stake within the staking tolerance is “good.” A 0.03 ft structure hub on a ginnie head is a placement tolerance. It is not the accuracy of the primary CCS83 network. Do not report a 0.03 ft hub as proof of 0.01 ft primary control.

Field notes and staking reports

Notes (paper or collector) should let you reconstruct the day:

• Request number, original versus restake, station limits, feature.
• Control occupied, checks, instrument calibration/collimation if used, temperature if EDM distances matter.
• As-staked coordinates versus design, with rejects when residuals exceed the allowed staking tolerance (Caltrans Chapter 7 points to Chapter 12 for those construction tolerances).
• Design issues found at conforms and inverts, reported to the RE the same day—not silently “fixed” on the stake.
• Monument preservation duties under Business and Professions Code §8771 when construction threatens marks: that is a staking-day duty, not a PLSS retracement.

Exam traps: staking from a blue-top as if it were CP-4; mixing epochs between the rover and the plans; marking a 1.67 ft curb cut as 1.7 ft when the spec wants hundredths; filing no cut sheet; starting work on a verbal request with the area not ready.