No person shall advertise or enter into a contract to perform any services requiring a license from or registration with the construction contractors board, the plumbing board or the electrical board without first being duly licensed or registered with such board. All contractors performing work within the city shall be licensed by the state of Oregon construction contractors board during the time of all phases of work and until completion of any or all contract work. No contractor shall employ any person to perform work covered by the construction contractors board unless that contractor is registered as nonexempt from workers' compensation coverage with the construction contractors board. (Ord. 647, 1-7-1997)