A laborer may perform any work that is not ordinarily performed by a mechanic or mechanic’s apprentice, but shall be paid the prevailing wage rate for the work performed. A laborer receiving the prevailing wage rate for laborers may not perform work ordinarily performed by a mechanic or mechanic’s apprentice. If a laborer performs work ordinarily performed by any mechanic or mechanic’s apprentice, the contractor or subcontractor shall pay the laborer for the entire time of performance of that work at the prevailing wage rate for a mechanic.