Certificate or permit required — Photo identification — Trainee supervision required — Medical gas piping installer endorsement — Penalty — Notice of infraction.

RCW 18.106.020
in effect
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(1) No person may engage in or offer to engage in the trade of plumbing without having a journey level certificate, specialty certificate, residential service certificate, temporary permit, or trainee certificate and photo identification in his or her possession. The department must establish by rule a requirement that the person also wear and visibly display his or her certificate or permit. A trainee must be supervised by a person who has a journey level certificate, specialty certificate, residential service certificate, or temporary permit, as specified in RCW 18.106.070 . Until January 1, 2021, no contractor may employ a person to engage in or offer to engage in the trade of plumbing unless the contractor is a registered plumbing contractor under chapter 18.27 RCW and the person performing the plumbing work has a journey level certificate, specialty certificate, temporary permit, or trainee certificate. After January 1, 2021, no contractor may employ a person to engage in or offer to engage in the trade of plumbing unless the contractor is a licensed plumbing contractor under this chapter and the person performing the plumbing work has a journey level certificate, specialty certificate, residential service certificate, temporary permit, or training certificate. (2) Without exception, no person may engage in or offer to engage in medical gas piping installation without having a certificate of competency as a journey level plumber and a medical gas piping installer endorsement and photo identification in his or her possession. The department must establish by rule a requirement that the person also wear and visibly display his or her endorsement. A trainee may engage in medical gas piping installation if he or she has a training certificate and is supervised by a person with a medical gas piping installer endorsement. No plumbing contractor may employ a person to engage in or offer to engage in medical gas piping installation unless the person employed has a certificate of competency as a journey level plumber and a medical gas piping installer endorsement. (3) Violation of this chapter is an infraction. Each day in which a person, firm, or corporation advertises, offers to do work, submits a bid, or performs any work in the trade of plumbing in violation of this chapter or employs a person in violation of this chapter is a separate infraction. Each worksite at which a person engages in the trade of plumbing in violation of this chapter or at which a person is employed in violation of this chapter is a separate infraction. (4) Notices of infractions for violations of this chapter may be issued to: (a) The person engaging in or offering to engage in the trade of plumbing in violation of this chapter; (b) The contractor in violation of this chapter; and (c) The contractor's employee who authorized the work assignment of the person employed in violation of this chapter. (5) It is unlawful for anyone required to be licensed under this chapter or registered under chapter 18.27 RCW to subcontract to or use anyone not licensed under this chapter for work covered by the provisions of this chapter. (1) No person may engage in or offer to engage in the trade of plumbing without having a journey level certificate, specialty certificate, residential service certificate, temporary permit, or trainee certificate and photo identification in his or her possession. The department must establish by rule a requirement that the person also wear and visibly display his or her certificate or permit. A trainee must be supervised by a person who has a journey level certificate, specialty certificate, residential service certificate, or temporary permit, as specified in RCW 18.106.070 . Until January 1, 2021, no contractor may employ a person to engage in or offer to engage in the trade of plumbing unless the contractor is a registered plumbing contractor under chapter 18.27 RCW and the person performing the plumbing work has a journey level certificate, specialty certificate, temporary permit, or trainee certificate. After January 1, 2021, no contractor may employ a person to engage in or offer to engage in the trade of plumbing unless the contractor is a licensed plumbing contractor under this chapter and the person performing the plumbing work has a journey level certificate, specialty certificate, residential service certificate, temporary permit, or training certificate. (2) Without exception, no person may engage in or offer to engage in medical gas piping installation without having a certificate of competency as a journey level plumber and a medical gas piping installer endorsement and photo identification in his or her possession. The department must establish by rule a requirement that the person also wear and visibly display his or her endorsement. A trainee may engage in medical gas piping installation if he or she has a training certificate and is supervised by a person with a medical gas piping installer endorsement. No plumbing contractor may employ a person to engage in or offer to engage in medical gas piping installation unless the person employed has a certificate of competency as a journey level plumber and a medical gas piping installer endorsement. (3) Violation of this chapter is an infraction. Each day in which a person, firm, or corporation advertises, offers to do work, submits a bid, or performs any work in the trade of plumbing in violation of this chapter or employs a person in violation of this chapter is a separate infraction. Each worksite at which a person engages in the trade of plumbing in violation of this chapter or at which a person is employed in violation of this chapter is a separate infraction. (4) Notices of infractions for violations of this chapter may be issued to: (a) The person engaging in or offering to engage in the trade of plumbing in violation of this chapter; (b) The contractor in violation of this chapter; and (c) The contractor's employee who authorized the work assignment of the person employed in violation of this chapter. (5) It is unlawful for anyone required to be licensed under this chapter or registered under chapter 18.27 RCW to subcontract to or use anyone not licensed under this chapter for work covered by the provisions of this chapter.
Source: WA Statutes (Official Site)URL: https://app.leg.wa.gov/RCW/default.aspx?cite=18.106&full=trueFetched: 6/28/2026

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