Wash. Rev. Code § 43.22A.040
A person desiring to be issued a certificate of manufactured home installation as provided in this chapter shall make application to the department, in such a form as required by the department.
Upon receipt of the application and evidence required in this chapter, the director shall review the information and make a determination as to whether the applicant is eligible to take the training course and examination for the certificate of manufactured home installation. An applicant must furnish written evidence of six months of experience under the direct supervision of a certified manufactured home installer, or other equivalent experience, in order to be eligible to take the training course and examination. The director shall establish reasonable rules for the training course and examinations to be given to applicants for certificates of manufactured home installation. Upon determining that the applicant is eligible to take the training course and examination, the director shall notify the applicant, indicating the time and place for taking the training course and examination.
The requirement that an applicant must be under the direct supervision of a certified manufactured home installer for six months only applies to applications made on or after July 1, 1996. For applications made before July 1, 1996, the department shall require evidence of experience to satisfy this requirement.
The director may allow other persons to take the training course and examination on manufactured home installation, without certification.
RCW 43.22A.040