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The following information is intended to provide some guidance regarding hiring of contractors and installation of plumbing and gas piping. Hiring an unregistered contractor or failure to obtain the necessary construction permits and required inspections is not only against the law, but may present significant and perhaps costly problems later.

Information regarding required permits and inspections, along with some general information pertaining to installation of plumbing and gas piping can be obtained on our Plumbing and Gas Piping permit homepage. Information regarding hiring a contractor can be found on the Washington State Department of Labor & Industries' website.


Can I do my own plumbing work?

In the State of Washington, Chapter 18.106 RCW contains the rules and regulations governing plumber certification. An owner may perform their own plumbing work. They may also enlist the help of a friend, neighbor, relative, or other acquaintance, provided that such persons are not being compensated for the services. If you are paying to have plumbing work done, the installer is required to be a certified journeyman plumber. They must also be a registered contractor or be employed by a registered contractor. More information is available from the Washington State Department of Labor & Industries.

Who can I hire to install plumbing and gas piping?

In the State of Washington, Chapter 18.27 RCW contains the rules and regulations governing contractor registration. All contractors who perform work, advertise or submit bids must be registered with the Department of Labor & Industries, post a bond and carry general liability insurance coverage. More information is available from the Washington State Department of Labor & Industries. In addition, there are specific requirements for installers of plumbing and gas piping as outlined in the following questions.

Can I do my own gas piping work?

Property owners can install gas piping on property they own. If you are paying to have gas piping work done, the installer is required to be a registered contractor or be employed by a registered contractor. Please note that within the City of Seattle only, a gas pipe installer must be the property owner, or they must hold a Seattle Gas Piping Mechanic License. You can find more information regarding this on the City of Seattle's website.

Who can purchase a plumbing or gas piping permit?

Property owners, general contractors and specialty contractors may purchase plumbing and gas piping permits whether they intend to perform the work themselves or contract for the services.