Prevailing wage & Davis-Bacon basics

Prevailing wage is the minimum hourly pay — a base wage rate plus a fringe benefit amount — that contractors must pay each class of worker on covered public construction work, set by the government for the type of work and the location rather than negotiated with the employee. On federal jobs the requirement comes from the Davis-Bacon Act; many states layer their own versions on state-funded work. If your crew is on a covered project, the published rate for their classification and county is the floor, regardless of what you pay the same people on private work.

The mechanics follow from that one idea: the government publishes the rates (a wage determination), you match each worker to a classification based on the work they actually perform, you pay at least the base plus fringe for that classification, and you prove it weekly with certified payroll. Everything that goes wrong on prevailing wage jobs goes wrong at one of those four steps.

One framing note before the detail: this guide is a map, not a ruling. The authoritative sources are the U.S. Department of Labor’s Wage and Hour Division, the official federal wage determination listings on SAM.gov, and your state’s labor department — and edge cases (site of work questions, coverage of trucking, survey crews, offsite fabrication) genuinely need counsel or the agency itself.

The Davis-Bacon Act (1931) requires payment of locally prevailing wages and fringe benefits on federal construction contracts over $2,000 — construction, alteration, or repair of public buildings and public works. A large family of “Davis-Bacon Related Acts” extends the same requirement to federally assisted construction: projects funded through federal grants, loans, loan guarantees, and insurance — highway money, housing programs, water infrastructure, energy programs, and more. Practically, that means a school or plant that never sees a federal contracting officer can still be a Davis-Bacon job because of how it is financed, and the coverage flows down to subcontractors at every tier. The prime’s obligations ride into your subcontract whether or not anyone highlighted the clause.

Alongside the federal scheme, roughly half the states have their own prevailing wage statutes — commonly called “little Davis-Bacon” laws — covering state- and locally-funded public work. They differ meaningfully: dollar thresholds range from a few hundred dollars to a million or more, rate-setting methods differ (some adopt union scale, some survey), certified payroll formats and filing systems differ, and some states have no such law at all. The operational takeaway is simple: coverage is a per-project fact you establish before you bid, from the bid documents and the funding source, not something to discover from a notice letter mid-job. A project can even carry both federal and state requirements at once, in which case the higher rate for each classification governs.

A wage determination is the government’s published schedule of minimum rates for a project, organized by worker classification (laborer, roofer, sheet metal worker, electrician, power equipment operator, and so on) within a county and a construction type — federal determinations come in four flavors: building, residential, highway, and heavy. The applicable determination is incorporated into the contract, and federal determinations are published on SAM.gov; states publish their own schedules through their labor departments.

Each classification line shows two numbers: a base hourly rate and a fringe rate. Both are owed. A line reading Roofer … $30.00 / $12.50 means every hour of roofer work on that project costs the worker no less than $42.50 in wages and benefits combined. Three reading rules save the most grief:

• The determination in the contract governs. Rates get updated periodically, but a project generally locks to the determination incorporated at award — bid from the one in the bid documents, not the newest one on the website (and not last year’s job).
• Classification follows the work, not the title. The same employee can be a roofer in the morning and a laborer doing cleanup in the afternoon, and each hour is owed its own classification’s rate — which requires time records that split the day.
• If the work you perform has no classification on the determination, there is a formal process (a “conformance”) to add one through the contracting agency and DOL — you do not get to invent a rate, and you should raise it before the work starts.

Stay with Roofer: $30.00 base + $12.50 fringe = $42.50 total. The fringe obligation can be satisfied three ways:

• All cash: pay $42.50 per hour in wages. Simple, and common for open-shop contractors with thin benefit plans — but every fringe dollar paid as cash is wages, which inflates the payroll-tax and workers’ comp base.
• Cash plus benefits: pay $30.00 in wages and contribute $12.50 per hour to bona fide fringe benefit plans — health insurance, pension/retirement, life insurance, apprenticeship training funds, certain vacation and holiday plans. “Bona fide” is a real test: the money must actually go to a legitimate plan, fund, or program for the worker’s benefit, on a schedule, with records.
• The mix: if your benefit plans cost $7.50 per hour, you owe the remaining $5.00 as cash, for $35.00 in wages plus $7.50 in benefits. Credit is taken at the plans’ actual hourly cost — and where benefits cover both public and private work, the hourly figure generally must be computed over all hours worked (annualized), not loaded onto prevailing wage hours to soak up the credit.

Now add overtime, because it is the spot everyone’s spreadsheet gets wrong. Under the federal rules, time-and-a-half applies to the base rate, while fringe rides along at straight rate. A 45-hour week for our roofer, paid all cash: overtime hours cost 1.5 × $30.00 + $12.50 = $57.50, not 1.5 × $42.50 = $63.75. The week: 40 × $42.50 + 5 × $57.50 = $1,700.00 + $287.50 = $1,987.50. (Some states compute overtime differently, and a few require overtime after 8 hours in a day — one more reason coverage research happens before the bid.)

Finally, the bid-side lesson hiding in the math: a $42.50 all-in rate is not your cost. Payroll taxes, workers’ comp, and liability insurance load on top of the wage portion, so the burdened cost of that hour lands well above the determination number. Estimating prevailing wage work at the determination rate, unburdened, is a quiet way to donate your margin.

Covered projects require certified payroll: a weekly report of every worker on the project — name and identifying number, classification, hours by day, rate paid, gross wages, deductions, net pay, and fringe handling — submitted to the contracting agency or prime. The federal vehicle is form WH-347; the form itself is technically optional, but the data is not, and nearly everyone uses the form because it is the shape reviewers expect. Many states and some agencies require electronic filing through their own portals instead of or in addition to the paper form.

Page two is the part that concentrates the mind: the Statement of Compliance, a signed certification by the contractor or an authorized officer that the payroll is correct and complete and that every worker was paid no less than the applicable rate. Signing a false one is a federal offense. This is why certified payroll should never be a Friday reconstruction from memory — it must fall out of real daily time records, kept by project and classification, with the splits documented on the day they happened.

The cadence matters too. Payrolls are due weekly, typically within seven days of the pay date, numbered sequentially, with “no work” payrolls filed for idle weeks on many jobs, and records retained for years afterward. Primes are responsible for collecting their subs’ payrolls, which is why a late or sloppy sub certified payroll shows up so fast as a held payment. A field-by-field walkthrough of the form lives in our WH-347 certified payroll guide.

The enforcement toolkit is blunt and effective. The first lever is the money: the contracting agency can withhold contract payments — from the prime, which means the prime withholds from you — sufficient to cover back wages the moment underpayments are found or certified payrolls go missing. Restitution means paying affected workers the difference for every underpaid hour, and on overtime violations federal law adds liquidated damages. Contract termination, with the government’s costs charged back, sits behind that.

The second lever is existential: debarment. Contractors found to have disregarded their obligations can be barred from federal and federally assisted work — generally for up to three years — and state schemes carry their own debarment lists. For a specialty contractor whose book leans on public work, a debarment is not a fine; it is the market disappearing. Falsified certified payrolls escalate matters from a wage dispute into fraud territory, with the personal exposure that implies for whoever signed.

Worth internalizing: investigations are routinely triggered by worker complaints and by desk review of the certified payrolls themselves — a laborer classification performing suspiciously skilled work at scale, hours that never split, fringe credits that do not add up. The paperwork is not a formality riding alongside compliance; it is where compliance is checked.

Strip away the statute names and prevailing wage compliance is a data problem: every hour needs a project, a classification, a rate with its fringe handling, and a weekly report that ties to the checks — signed under penalty. Contractors get in trouble not because the rules are unknowable but because the hours were captured loosely and the paperwork was reconstructed afterward.

That is the problem SitewideOps is built to close. Crews clock time in the field app against the job and cost code, prevailing-wage rate groups apply the right certified rates to covered work, and the same hours flow two directions at once: into job costing as burdened labor, and into WH-347 certified payroll generated from those very time records — one set of hours, so the payroll you certify and the labor cost you manage can never quietly disagree. Scheduling the right crews onto the covered work in the first place is the dispatch side of the same discipline. If public work is in your book, a free 21-day demo account is the fastest way to see the loop end to end.