The ratio of apprentices to journey-level worker shall not be more than one (1) apprentice to the first one (1) licensed plumber journey-level worker in full employment for the first two (2) apprentices on the jobsite. The fab shop will be defined as a separate jobsite. Additional apprentices are authorized at a ratio of one (1) apprentice for each additional three (3) licensed plumber journey-level worker(s). (See ORS 660.126 (f))
The following image illustrates our present Ratio/Shop Requirements:
The following rules are obtained from Oregon Administrative Rules 839-011-0143 and 839-011-0290. We have included what we consider to be important reminders regarding the use of apprentices, required ratio, supervision of apprentices and phased supervision. For a complete listing of the Oregon Rules please click the link above.
Oregon Administrative Rule 839-011-0143
(6) In licensed trades, an apprentice must be supervised by a journey worker in the same or a higher license classification than the apprentice, unless the local committee that the apprentice is registered to has approved supervision by a journeyworker holding a license covering the specific work being performed by the apprentice on the job site.
Oregon Administrative Rule 839-011-0290
Plumber Apprentices — Phased Supervision
(1) The Division shall issue plumbing apprentice licenses to active apprentices or trainees registered to standards approved by the Council. Apprentice license formats shall be jointly agreed to by the Division and the Oregon Building Codes Division.
(2) All apprentices and trainees must be directly supervised in accordance with OAR 839-011-0143, unless approved for phased supervision.
(3) Pursuant to OAR 918-695-0140, a local committee may take action to permit plumbing apprentices to work under phased supervision under the following circumstances:
(a) The plumber apprentice must work in the physical presence of an appropriate journey level plumber; and
(b) An appropriate journey level plumber present at the immediate work site at all times, except for not more than a cumulative thirty (30) minutes during any work shift during which time the journeyworker is immediately available by voice communication.
(4) The plumber apprentice may work under phased supervision when the following specific conditions are met:
(a) The appropriate journeyworker is immediately available to the apprentice by voice communication (immediately available means that the apprentice can reach 
the appropriate journeyworker within a 15-minute period);
(b) The appropriate journeyworker 
meets with the apprentice 
at least once each day to go over the work done by the apprentice;
(c) The activity is consistent with the committee’s work requirements as established in its written policy;
(d) There is only one apprentice on the job site; and
(e) The apprentice has been specifically approved for one (1) or more of the following phases:
(A) Phase 1: The apprentice only engages in water heater replacement or conversion after completing at least six (6) months of work experience, eight (8) hours of related instruction and is evaluated and authorized to do this type of work by the committee;
(B) Phase 2: The apprentice engages in work covered in Phase 1 and minor repairs in a one (1) or two (2) family dwelling after completion of three (3) periods of work experience, the appropriate related instruction for three (3) periods and is evaluated and authorized to do this type of work by the committee;
(C) Phase 3: The apprentice engages in work covered in Phase 1 and 2, and general repairs and replacement of existing installations after completion of four (4) periods of work experience, the appropriate related instruction for four (4) periods and is evaluated and authorized to do this type of work by the committee; or
(D) Phase 4: The apprentice engages in work covered in Phase 1, 2 and 3, and new or remodel installations after completing five (5) periods of work experience, the appropriate related instruction for five (5) periods and is evaluated and authorized to do this type of work by the committee.
(5) Phased supervision licenses will be issued by the Division upon notification of committee approval and reissued for the duration of the program unless the committee takes action to rescind approval.
REMEMBER: Any time two or more apprentices are on the same jobsite (including the shop), regardless of phased supervision status, the proper number of Journeymen Plumbers must be present. Any time two or more apprentices are together on a jobsite or at the shop, the following ratio requirements apply:
2 Journey Level Plumbers to 2 Apprentices
5 Journey Level Plumbers to 3 Apprentices
8 Journey Level Plumbers to 4 Apprentices