Picking the right classification, and what to do when the trade is not listed
Match each worker to a wage determination classification by the work performed, and add a missing trade, such as HVAC, through an SF-1444 conformance.
6 min read · Updated October 10, 2026 · Sources checked October 10, 2026
The short answer
Classify each hour by the work performed, using the classifications on the wage determination in your contract and the way contractors in that area divide the work. Read the parentheses, group lists and footnotes before deciding a trade is missing, because some determinations fold HVAC into pipefitter or sheet metal worker. If no listed classification does the work, you complete Standard Form 1444, the contracting officer sends it to the Wage and Hour Division, and the rate it sets is owed from the first day the work was done.
The contract clause pays for the work. Workers "must be paid the appropriate wage rate and fringe benefits on the wage determination for the classification(s) of work actually performed, without regard to skill." The WH-347 instructions say the same for column 3: list the classification "for the work actually performed by each worker."
So the question for each worker is what they did this week, hour by hour. Their title on your payroll system doesn't decide it.
Start with the determination in your contract
Use the determination and modification incorporated in the contract, for the county and construction type of the project. Reading a wage determination covers which version applies.
Then read every entry, including the text in parentheses and the footnotes. Determinations often say what a classification includes:
- Michigan's MI20260101 lists "Pipefitter, includes HVAC pipe and unit installation," "Plumber, excludes HVAC pipe and unit installation," and "Sheet metal worker (including HVAC duct installation; excluding HVAC system installation)."
- Florida's FL20260218 lists "Laborer: common or general, including cement mason tending and pipelaying."
- The same Michigan sheet groups its operators by equipment. Group 7 names backhoe, bobcat, bulldozer, loader, roller and others; group 8 is forklift. A footnote adds $.25 per hour for crane operators who climb 50 feet or more to the work station.
The group lists and footnotes are part of the rate. On that sheet, a worker driving a forklift is in group 8 for those hours, even if your crew calls them a laborer.
Area practice decides the close calls
There is no national dictionary of trades. The Department of Labor's handbook says "under the DBA there are not standard classification definitions." When the determination's wording doesn't settle it, the proper classification is the one used by the contractors whose rates were found to prevail in the area. That rule comes from a 1977 Wage Appeals Board decision, Fry Brothers Corp., and DOL settles disputes with an area practice survey of those contractors.
For a small sub, the practical step is to ask before the work starts. Call the contracting agency's labor advisor with the task, the determination number and the two classifications you're choosing between. Put the answer in the project file.
Laborer or tradesperson when someone tends a trade
Some determinations name tending work: Ohio's residential OH20250018 has "Laborer (Mason Tender-Brick)" as its own rate, and the Florida sheet folds cement mason tending into the general laborer rate. Where the sheet names it, use it.
Where it doesn't, area practice decides whether carrying, staging and cleaning up for carpenters is laborer work. Hours a worker spends doing the carpentry itself are a different matter. If contractors in the area classify that work as carpentry, those hours are owed at the carpenter rate, whatever the worker's experience level.
A "helper" rate can't fill the gap either. DOL's conformance guidance says a helper classification can't be added where any of the helper's work is performed by a classification already on the determination.
One worker, two trades
A worker who tends in the morning and frames in the afternoon is paid each rate for the hours in each, but only if your records show the split. The regulation allows it "provided, that the employer's payroll records accurately set forth the time spent in each classification." On the WH-347 that worker gets 2 rows with the same entry number. How the two rows work.
Worked example: an HVAC mechanic with no HVAC line
Your crew is setting rooftop units, running refrigerant piping and hanging duct on a federally funded clinic. The determination has no classification called HVAC mechanic. Go through 3 checks in order.
1. Does a listed classification say it covers the work? If the sheet has entries such as Michigan's, the answer is yes. Unit setting and piping are pipefitter hours; duct is sheet metal hours. A mechanic who did both in a week goes on 2 rows. No conformance.
2. Does a listed classification do the work in this area? Say the sheet lists plumber and sheet metal worker with no parentheses. The question is whether plumbers or sheet metal workers employed by the prevailing contractors did this work on similar projects in the area. DOL's guidance looks at the year before bid opening or award. If they did, that classification applies and a conformance request will be denied. In American Building Automation (Administrative Review Board, 2001), a building controls technician classification was refused because plumbers in the area had done that work.
3. If nothing listed does it, request a conformance. The criteria are in 29 CFR 5.5(a)(1)(iii), and all 3 must be met:
- The work to be performed by the classification requested is not performed by a classification in the wage determination.
- The classification is used in the area by the construction industry.
- The proposed wage rate, including any bona fide fringe benefits, bears a reasonable relationship to the wage rates contained in the wage determination.
The process can't be used to split or subdivide a classification already on the sheet.
Filing the SF-1444
The contractor fills in items 3 through 16 of Standard Form 1444, keeps a pending copy, and submits it to the contracting officer. A subcontractor signs block 14 and the prime signs block 15, so a sub's request goes through the prime. Block 16 is for the workers or their representative to agree or disagree. Block 13 takes the determination number and date, and the proposed classification, wage rate and fringe.
The contracting officer emails the request to the Wage and Hour Division with a recommendation. If the parties disagree, the officer sends everyone's views. The Division approves, modifies or disapproves it within 30 days of receipt, or says it needs more time. No answer within 30 days is not approval.
For the rate, DOL compares a proposed skilled craft with the other skilled crafts on the sheet, leaving out laborers, truck drivers and operators. Example, with made-up figures: a residential sheet lists electrician at $34.10 plus $12.85, plumber at $31.60 plus $10.40, carpenter at $27.25 plus $8.90, and laborer at $19.80 plus $5.15. An HVAC mechanic proposed at $31.60 plus $10.40 sits among the skilled rates. Appeal decisions DOL cites have refused skilled trades conformed at the laborer rate when most skilled crafts on the sheet paid more.
Pay from the first day
The approved rate "must be paid to all workers performing work in the classification under this contract from the first day on which work is performed in the classification." Pay at least your proposed rate while you wait. If the Division modifies the rate upward, you owe the difference back to day 1.
Say the mechanic worked 40 straight time and 2 overtime hours in each of 3 weeks at the proposed $31.60, and the Division sets $33.00 with the same fringe. Each week was short $60.20 ($1.40 on 40 hours plus $2.10 on 2 overtime hours), so you owe $180.60 for the 3 weeks. Correct those payrolls with the approved classification name and rate. Correcting a filed payroll and paying back wages cover the paperwork.
The approval covers this contract only. DOL's appeal decisions say a contractor can't rely on a conformance approved for another contract, even at the same location, so the next job needs its own request if the sheet still lacks the trade.
Questions people ask
- What classification do I use for an HVAC tech on a Davis-Bacon job?
- The one on your determination that covers the task. Some sheets say it outright, as in "Pipefitter, includes HVAC pipe and unit installation" or "Sheet metal worker (including HVAC duct installation)." If nothing listed covers the work, request a conformance on SF-1444.
- Can I use the closest trade on the sheet until the conformance comes back?
- Only if that trade performs the work in your area, in which case no conformance is needed. If you file, keep paying at least your proposed rate; the approved rate applies from the first day.
- Is a worker who tends carpenters a laborer or a carpenter?
- It depends on the determination and area practice. Carrying and staging material for a trade is laborer work where the area treats it that way. Hours spent doing work the area classifies as carpentry are owed at the carpenter rate.
Sources
- 29 CFR 5.5(a)(1)(i) and (iii), work actually performed and conformance (eCFR)
- FAR 22.406-3, Additional classifications
- Standard Form 1444, Request for Authorization of Additional Classification and Rate (Rev. 10/2023), GSA
- Davis-Bacon conformances, Prevailing Wage Resource Book (PDF), U.S. Department of Labor
- Davis-Bacon compliance principles, Prevailing Wage Resource Book, U.S. Department of Labor
- Field Operations Handbook chapter 15, 15f05 area practice (PDF), U.S. Department of Labor
- Instructions for completing Form WH-347 (column 3)
- General decision MI20260101, modification 2 (Michigan, building)
- General decision FL20260218, modification 1 (Florida, building)
- General decision OH20250018, modification 4 (Ohio, residential)
The math in this guide runs on every line in CertifiedHours.
Type the hours; the overtime split, fringe handling, and wage-determination checks happen as you type, and the WH-347 prints itself. Free for one payroll a month.
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This guide explains the rules as written and is not legal advice. Your contract, the wage determination, and any state law control when they differ.