Overtime and shift pay on prevailing-wage jobs, done right

Two overtime systems, not one

Most payroll software is built around federal FLSA overtime: time-and-a-half after 40 hours in a week, period. Public works does not run on that rule. California prevailing-wage overtime is triggered by the day as well as the week, it runs off a different base rate, and on some crafts the day of the week changes the multiplier entirely. A contractor who applies ordinary FLSA logic to a certified payroll is not being conservative — they are usually computing the wrong number, in both directions.

The eight-hour day

Labor Code §1815 sets the baseline: eight hours is a day's work on public works, and a worker cannot be required or permitted to work more than 8 hours in a calendar day or 40 hours in a calendar week unless paid overtime — not less than 1.5 times the basic rate of pay — for every hour beyond those thresholds. That means daily overtime is its own trigger, independent of the weekly total. A worker who logs four 10-hour days and takes the fifth day off has 8 hours of daily overtime that week, even though the weekly total never crosses 40. FLSA logic alone would miss it entirely.

What rate the premium is computed on

The prevailing wage determination for the craft sets a basic hourly rate and, separately, required fringe benefit contributions (health and welfare, pension, training, vacation/holiday, and so on). The overtime premium under §1815 applies to the basic hourly rate — not the blended total that includes fringes. Fringe contributions are generally owed for every hour actually worked, including overtime hours, but the contribution itself is not multiplied by 1.5 or 2.

That distinction is exactly where a well-intentioned payroll clerk goes wrong: multiplying the full base-plus-fringe rate by 1.5 overstates the wage owed on paper (rarely challenged, but it misstates the record and can distort fringe-fund reporting), while multiplying only a partial base rate — say, missing a per-craft add-on — understates it, which is the version that draws a Labor Code §1775 penalty. The governing document is always the specific wage determination for that craft, county, and bid-advertisement date; it typically spells out its own overtime and premium language, and that language controls over any general assumption.

Saturday, Sunday, and holiday work

This is the piece that trips up contractors who have only worked private commercial jobs. Many prevailing-wage determinations require a premium for Saturday, Sunday, or recognized holiday work regardless of the daily or weekly hour count — a worker can put in a single eight-hour Saturday shift and still be owed a Saturday premium, because the day itself is what triggers it, not the hour total. The specific multiplier and which days qualify (Saturday is frequently 1.5x, Sunday and holidays frequently 2x) vary by craft and by determination. There is no single statewide table; the applicable wage determination is the only reliable source.

• Pull the determination's overtime and holiday-pay language for the specific craft before scheduling weekend or holiday work, not after.
• Confirm which calendar holidays the determination recognizes — it is not always the same list as the contractor's own holiday policy.
• If a crew works a compressed schedule (four 10s), check both the daily-overtime trigger and any weekend-day premium separately.

Where the math goes wrong in practice

• Treating it as pure FLSA. Paying overtime only after 40 hours/week and missing the daily 8-hour trigger under §1815.
• Multiplying the wrong base. Applying 1.5x to base-plus-fringe instead of the basic rate the determination specifies, or vice versa.
• Missing the weekend premium. Assuming Saturday or Sunday hours are ordinary time because the daily and weekly thresholds weren't hit.
• Using the wrong determination's rate. Overtime computed correctly, but off a base rate for the wrong craft classification or the wrong bid-advertisement date.
• Compressed-schedule blind spots. 4/10 or 9/80 schedules that are lawful for private work but generate daily overtime nobody budgeted for on a public job.

Federal work adds its own layer

On Davis-Bacon and Davis-Bacon Related Act work, overtime is generally governed by the Contract Work Hours and Safety Standards Act (CWHSSA), which requires time-and-a-half after 40 hours in a week on covered federal contracts — a weekly, not daily, trigger. On a California project that draws federal funds and is therefore subject to both regimes, a contractor may need to track a daily threshold for state purposes and a weekly threshold for federal purposes on the same crew, and pay whichever produces the higher amount for each hour in question. Reconciling the two by hand, project by project, is where errors compound fastest.

The rate is rarely the mistake. The trigger — which hour, which day, which base — is where prevailing-wage overtime actually goes wrong.

Keeping the certified payroll consistent

Whatever the overtime rule produces, it has to show up correctly on the certified payroll record itself: straight-time and overtime hours broken out, the correct rate applied to each, and fringe contributions reported per hour actually worked. An overtime error that looks small on a single week's record is the kind of discrepancy that surfaces at audit across an entire project, well after the payroll periods have closed and the fix requires reconstructing pay history rather than a single correction.

This article is educational and does not constitute legal or tax advice. Statutes and agency requirements change; confirm current rules with the California DIR, the U.S. Department of Labor, the IRS, or qualified counsel before relying on them. Aeternus Dynamics is a compliance and advisory firm, not a law or accounting firm.