Administrative Rules of Montana
Department 24 - LABOR AND INDUSTRY
Chapter 24.301 - BUILDING CODES
Subchapter 24.301.3 - Plumbing Requirements
Rule 24.301.301 - INCORPORATION BY REFERENCE OF UNIFORM PLUMBING CODE

(a) Appendix A, Recommended Rules for Sizing the Water Supply System is adopted.

(b) Appendix B, Explanatory Notes on Combination Waste and Vent Systems is adopted.

(c) Appendix C, Alternate Plumbing Systems is adopted.

(d) Appendix D, Sizing Stormwater Drainage Systems is adopted.

(e) Appendix K, Potable Rainwater Catchment Systems is adopted.

(f) Appendix L, Sustainable Practices is adopted.

(g) Appendix M, Peak Water Demand Calculator is adopted.

(h) Appendix N, Impact of Water Temperature on the Potential for Scalding and Legionella Growth is adopted.

(i) Subsection 103.3.1, Licensing, is amended with the addition of the following language: The requirements for who must be licensed to perform plumbing work is regulated by Title 37, chapter 69, MCA.

(j) Subsections 104.1, 104.2, 104.3, 104.3.2, 104.4, 104.5, 105.0, 105.4, 106.1, 106.3, and 107.0 will be left as is for use by local governments (i.e., municipalities and counties), but will not be used by the department and the state of Montana. For the purposes of enforcement by the department, these subsections are replaced with provisions of Title 50, chapter 60, part 5, MCA.

(k) Delete Table 104.5 - PLUMBING PERMIT FEES and replace with the following schedule:

(l) Section 218, Definition of Plumbing System, is amended to read: "Includes all potable water and alternate water sources including supply and distribution pipes, all plumbing fixtures and traps, all drainage and vent pipes, building drains and building sewers, including their respective joints and connections, devices, receptacles, and appurtenances within the property line of any premises, and includes water heaters and vents for the premises."

(m) Table 422.1, Minimum Plumbing Facilities, is deleted and replaced with ARM 24.301.351, Minimum Required Plumbing Fixtures.

(n) Delete Subsection 603.4.2.

(o) Subsection 603.5.10, is amended with the addition of the following language: "Boiler feed lines, in single-family dwellings on their own private well, may be protected with a dual check valve with intermediate atmospheric vent when a nontoxic transfer fluid is utilized in the boiler."

(p) Subsection 604.3, the exception is amended to read as follows: Exception: Type M copper tubing may be used for water piping when piping is above ground in, or on, a building.

(q) Subsection 605.12.2, Solvent Cement Joints, delete the third sentence and replace with the following: "Where surfaces to be joined are cleaned and free of dirt, moisture, oil, and other foreign material, apply approved primer in accordance with ASTM F 656."

(r) Subsection 610.8, last sentence, is amended to read as follows: No building supply pipe shall be less than 3/4 inch (19.1 mm) in inside diameter.

(s) Subsection 612.0, Residential Fire Sprinkler Systems, is deleted in its entirety.

(t) Subsection 704.3, is amended by deleting the first sentence and replacing it with, "There may not be a direct connection between the sewerage system and any drains originating from equipment in which food, portable equipment, or utensils are placed." Exception: A warewashing (3-compartment) sink may have a direct connection only when used as a wash bin, rinse bin, and sanitizing bin and shall not be used for any other purpose. Establishments that use the sanitizing bin of their warewashing sink to wash produce or conduct other food preparation must maintain an indirect connection and are not eligible for this exception.

(u) Subsection 705.6.2, Solvent Cement Joints, delete the third sentence and replace with the following: "Where surfaces to be joined are cleaned and free of dirt, moisture, oil, and other foreign material, apply approved primer in accordance with ASTM F 656."

(v) Subsection 707.4 is amended by deleting the first sentence and replacing with, "Each horizontal drainage pipe shall be provided with a cleanout at its upper terminal and each run of piping, which is more than 50 feet in total developed length, shall be provided with a cleanout for each 50 feet, or fraction thereof, in length of such piping."

(w) Section 708.1, is amended to read as follows: Horizontal drainage piping shall be run in practical alignment and a uniform slope of not less than 1/4 of an inch per foot or 2 percent toward the point of disposal provided that, where it is impractical due to the depth of the street sewer or to the structural features or to the arrangement of any building or structure to obtain a slope of 1/4 of an inch per foot or 2 percent, any such pipe or piping 2 inches or larger in diameter may have a slope of not less than 1/8 of an inch per foot or 1 percent.

(x) Subsection 718.1, the exception is amended to read as follows: Exception: Where it is impractical, due to the depth of the street sewer or to the structural features or to the arrangement of any building or structure, to obtain a slope of 1/4 of an inch per foot, any pipe or piping 3 inches or larger in diameter may have a slope of 1/8 of an inch per foot and any such pipe or piping 8 inches in diameter or larger may have a slope of 1/16 of an inch per foot.

(y) Subsection 807.3, Domestic Dishwashing Machine, add exception as follows: "Exception #1: The waste connection of a residential dishwasher shall connect directly to a wye branch fitting on the tailpiece of the kitchen sink, directly to the dishwasher connection of a food waste disposer, or through an air break to a standpipe. The waste line of a residential dishwasher shall rise and be securely fastened to the underside of the sink rim or countertop."

(z) Subsection 906.1, the first sentence is amended to read as follows: Each vent pipe or stack shall extend through its flashing and shall terminate vertically not less than 12 inches above the roof nor less than one foot from any vertical surface.

(aa) Subsection 906.3, is amended to read as follows: Vent pipes shall be extended separately or combined, of full required size, not less than 12 inches above the roof or fire wall.

(ab) Subsection 906.7, is amended to read as follows: Frost and Snow Closure: Where frost or snow closure is likely to occur in locations having a minimum design temperature below zero degrees Fahrenheit vent terminals shall be a minimum of 3 inches in diameter, but in no event smaller than the required vent pipe. The change in diameter shall be made inside the building at least 1 foot below the roof and terminate not less than 12 inches above the roof, or as required by the administrative authority.

(ac) Subsection 907.1 is amended to read, "Wet Venting."

(ad) Subsection 907.1.1 is deleted and replaced with, "Wet venting is limited to drainage piping receiving the discharge from the trap arm of one and two fixture unit fixtures that also serves as a vent for not to exceed four fixtures. All wet vented fixtures shall be within the same story; provided, further, that fixtures with a continuous vent discharging into a wet vent shall be within the same story as the wet vented fixtures."

(ae) Subsection 907.1.2, is amended to read as follows: "The piping between any two consecutive inlet levels shall be considered a wet vented section. Each wet vented section shall be a minimum of one pipe size larger than the required minimum waste pipe size of the upper fixture or shall be one pipe size larger than the required minimum pipe size for the sum of the fixture units served by such wet vented section, whichever is larger, but in no case less than two inches."

(af) Subsection 907.2 is amended with addition of the following: "Bathroom group locations include private bathrooms, private patient hospital rooms, commercial toilet rooms with only one toilet, one lavatory and may include one floor drain."

(ag) Chapter 12, Fuel Piping, is deleted and replaced with the International Fuel Gas Code.

(ah) Chapter 13, Health Care Facilities and Medical Gas and Vacuum Systems, is deleted except for Subsections 1301.0, 1302.0, and 1303.0, Health Care Facilities. In lieu of Chapter 13, except for the subsections not deleted, the department adopts and incorporates by reference the National Fire Protection Association's Standard NFPA 99, 2018 edition, Chapters 1 through 5 and Chapter 15 for the exclusive use as a standard for medical gas and vacuum systems, unless a different edition date is specifically stated, as the standard for the installation of medical gas and vacuum systems. The requirements of this rule shall not be construed as to replace or supersede any additional requirements for testing and certification of medical gas and vacuum systems, including independent third-party certification of systems, as may be applicable. NFPA 99 is a nationally recognized standard setting forth minimum standards and requirements for medical gas and vacuum systems. A copy of NFPA 99 may be obtained from the National Fire Protection Association at www.nfpa.org.