Prevailing wages are predicated on a "per hour" and "per diem" basis.  It is an improper practice to pay a lump sum salary or accrued piecework rate for work on a public works project under California law. Occasionally, employers believe that dividing the hours worked into the lump sum pay and then reporting this quotient as the "hourly rate paid" is an acceptable solution.  There are problems with this approach however.

Regarding stardard salsary type methods, the law generally requires salaries for non-executive personnel to be based on a specific amount of hours. To divide this predetermined amount-per-hour into some other amount per hour violates the essential basis of the employement contract.

For "piecework", the rate is not tied to a timeline at all (except possibly a certain "finish by" deadline) which is incongruous with the principle of the per hour, per diem rate of pay contemplated in the public works code.

It is not acceptable to "back into" the prevailing wage from a preset salary or piecework amount of pay. The hours worked by workers on public works projects must be paid individually, in amounts equal to or greater than the applicable prevailing wage determination.