MT Journeyman Plumber cheat sheet

UPC 2021 is the adopted model code; local amendments and the Montana Plumbing Code control where they differ, and the more restrictive provision governs.

Permits are required before installing, altering, repairing, or replacing plumbing systems, except for minor repairs such as stopping leaks, clearing stoppages, or replacing exposed fixture fittings.

Fixtures must be accessible for service; no plumbing fixture may be installed unless it is listed and complies with an approved standard recognized by the code.

Prohibited installations include concealed slip joints, direct connections between potable water and drainage, and installation of fixtures in rooms lacking required clearances and ventilation.

Testing: drainage and vent systems require a water test of 10 ft head or an air test of 5 psi for 15 minutes before concealment; water supply piping is tested at working pressure or 100 psi for 1 hour.

Materials must be approved and identified; dissimilar metals must be separated by dielectric fittings or approved isolation to prevent galvanic corrosion.

Vents must terminate outdoors at least 6 inches above the roof, and at least 10 feet from any window, door, or air intake, or 2 feet above such openings.

Code applies to new work and to repairs or alterations that affect the system's capacity, safety, or sanitation performance.

Fixture unit (FU) values are assigned per fixture type in the drainage fixture unit (DFU) and water supply fixture unit (WSFU) tables; use the correct table for drain vs. supply sizing.

Common DFU values: water closet 3, lavatory 1, bathtub 2, shower 2, kitchen sink 2, floor drain 2, washing machine 2, laundry tub 2, urinal 4 (tank-type 2 in some editions).

Common WSFU values (private): water closet 2.5, lavatory 1, bathtub 1.4, shower 1.4, kitchen sink 1.4, washing machine 1.4; convert to gallons per minute with the supply conversion table.

Water closet DFU of 3 is the standard basis; a 1.6 gpf or lower toilet still counts as 3 DFU unless the code table specifies otherwise.

Drainage pipe sizing uses the DFU table with slope limitations; smaller pipe sizes carry fewer fixture units and the allowable load decreases as slope decreases.

Water supply sizing uses total WSFU from the building supply tables; the meter and service must be sized for the total demand plus pressure loss.

Fixture clearances: water closets require at least 15 inches from centerline to side wall and 21 inches in front; lavatories and other fixtures have similar minimum spacing requirements.

Each fixture must have a trap, and each trap must have a vent unless it is a listed combination fixture; no fixture may be double-trapped or have more than one trap.

Drainage pipe must be installed with continuous slope: 1/4 inch per foot for pipe 2-1/2 inches and smaller, and 1/8 inch per foot for 3 inches and larger.

Horizontal drainage lines must be supported at maximum intervals per material: plastic at 4-foot intervals, cast iron at 5-foot intervals, and copper at 10-foot intervals.

Vent pipe sizes: the vent must not be smaller than the drain it serves in most cases; a 1-1/2 inch vent is the minimum for a water closet, and 1-1/4 inch is minimum for other fixtures.

Cleanouts are required at the base of each stack, at the end of each horizontal drain, and at intervals not exceeding 100 feet in horizontal runs.

Water supply pipe must be protected from freezing and from backflow; an air gap or approved backflow prevention device is required at all connections to fixtures and appliances.

Joints: solvent cement for PVC/CPVC, lead-free solder or press fittings for copper, and mechanical couplings must be listed for the application; no lead-based solder is permitted.

Trap arms must be no more than 30 inches from the fixture and the trap seal must be between 2 and 4 inches deep.

Water hammer arrestors and expansion control are required where quick-closing valves or thermal expansion in a closed system can create excessive pressure.

Shower and tub/shower valves must be pressure-balancing or thermostatic, with the maximum water temperature limited to 120 degrees F at the fixture.

Montana plumbing work is regulated by the Montana Department of Labor and Industry, which administers licensing and adopts the Montana Plumbing Code by administrative rule.

A journeyman plumber license requires a combination of documented work experience and passage of the journeyman examination; experience hours are verified by the employer or supervising master plumber.

A master plumber license is required to contract for plumbing work, obtain permits, and supervise journeyman plumbers and apprentices; a journeyman may work only under a master's supervision.

Apprentices must be registered and work under the direct supervision of a licensed journeyman or master plumber; apprentice hours are tracked toward journeyman eligibility.

Continuing education is required for license renewal; the number of hours and approved topics are set by department rule.

Plumbing permits must be obtained from the local jurisdiction before work begins, and inspections must be requested at required stages: rough-in, and final.

Licensees must display their license or carry it and provide it on request; unlicensed contracting is subject to civil penalties and license discipline.

Reciprocity or license by examination endorsement may be available for licensees from other states with comparable requirements, subject to department review.

Statutes and rules are amended periodically; the current Montana Plumbing Code and department rules control over outdated study materials.

Rough-in inspections must be approved before piping is concealed; the inspector may require a water or air test on any portion of the system.

A water test on drainage piping requires filling the system with water to a depth of at least 10 feet at the lowest point, or to the highest point of the system, and holding for 15 minutes.

An air test on drainage piping requires 5 psi of pressure held for 15 minutes with no drop; a gauge is required at the test point.

Water supply piping is tested with the system under working pressure or 100 psi, whichever is greater, for at least 1 hour with no leaks.

Final inspection requires all fixtures installed, traps primed, water heater operational, and all vents terminating properly.

Code sections are organized by topic: Chapter 4 fixtures, Chapter 6 water supply, Chapter 7 sanitary drainage, Chapter 8 vents, Chapter 9 traps and cleanouts, Chapter 10 joints and connections.

A plumbing system must be designed by a licensed engineer when the occupancy or size exceeds the prescriptive limits of the code.

Fixture counts are determined from the occupancy load and the fixture ratio tables; assembly, business, and residential occupancies have different ratios.

The total WSFU is converted to gallons per minute using the supply fixture unit table; the service and meter must handle peak demand plus pressure loss.

Water service sizing must account for the developed length of pipe, elevation loss, and the pressure required at the highest fixture.

A minimum of 8 psi residual pressure is required at the fixture outlet under flow conditions; the design must account for friction loss.

Drainage fixture unit loads are cumulative; the building drain must be sized for the total DFU plus the slope of the run.

Grease interceptors are required for commercial kitchens and other fixtures discharging grease-laden waste, sized by the fixture flow rate and retention time.

Indirect waste connections are required for fixtures such as food service sinks, sterilizers, and dishwashers; the waste must discharge through an air gap.

A vent stack must extend at least 6 inches above the roof and terminate with an approved vent cap; a flat roof requires a minimum height above the roof surface.

A common vent may serve two fixtures on the same floor if the fixtures are within the allowed distance and the vent is sized for the combined load.

A wet vent may serve a fixture if it is sized and installed per the code; a dry vent may not be used as a drain.

Each trap must be protected by a vent; a trap arm may not exceed the distance permitted by the pipe size: 5 feet for 1-1/2 inch, 6 feet for 2 inch, and 10 feet for 3 inch.

A trap seal must be maintained by a vent; a trap that loses its seal allows sewer gas to enter the building.

Backwater valves are required where the building drain is below the level of the public sewer or where flooding is possible.

Water supply piping must be installed with a minimum cover and protected from freezing; in Montana, freeze protection is critical and piping must be insulated or heat-traced where required.

The department may investigate complaints, issue citations, and suspend or revoke a license for violations of the plumbing statutes or rules.

Work performed without a permit or by an unlicensed person may require removal and reinstallation at the owner's expense.

A licensed plumber must provide a written contract for work over the threshold set by statute, including scope, price, and timeline.

The department adopts the plumbing code by reference; the current edition and any amendments are published in the administrative rules.

License renewal requires payment of fees and completion of continuing education; late renewal may require a penalty or reexamination.

A journeyman plumber may not supervise an apprentice unless authorized; supervision ratios are set by rule.

Local jurisdictions may adopt additional requirements, but they may not be less restrictive than the state code.

Water closets must be listed and must not exceed 1.6 gallons per flush; urinals must not exceed 1.0 gallon per flush.

Showerheads must not exceed 2.5 gallons per minute at 80 psi; multiple showerheads are counted together.

Lavatory faucets must not exceed 2.2 gallons per minute; kitchen faucets must not exceed 2.2 gallons per minute.

A floor drain must have a trap and a strainer; floor drains in food service areas must be sized for the expected flow.

A drinking fountain must be provided with a minimum number based on occupancy; the fixture must be accessible.

A water heater must be equipped with a temperature and pressure relief valve piped to a safe discharge point.

Fixture units for a water heater are based on the tank capacity and recovery rate; the supply sizing must account for the demand.

PVC pipe is permitted for drainage and vent systems but not for hot water distribution; CPVC is permitted for hot and cold water.

PEX is permitted for water distribution where listed and installed with approved fittings; it must be protected from UV exposure and freezing.

Copper tube types K, L, and M are permitted for water supply; type M is not permitted for underground installation.

Cast iron soil pipe is used for drainage where required by code or for sound attenuation; hubless couplings must be listed.

Galvanized steel pipe is permitted for water supply but must not be used with copper in a way that causes galvanic corrosion.

No lead content is permitted in pipe, solder, or flux used for potable water; lead-free is defined as not more than 0.25 percent lead by weight.

All materials must be listed and labeled by an approved agency; unlisted materials may not be installed.

The code official has authority to interpret the code, approve alternate materials and methods, and require tests to verify compliance.

An alternate material or method may be approved if it is equivalent in quality, strength, effectiveness, fire resistance, durability, and safety.

A permit application must include plans, specifications, and the name of the licensed contractor; work may not begin until the permit is issued.

The code official may revoke a permit for false statements or for work that does not comply with the approved plans.

A certificate of occupancy may not be issued until the plumbing final inspection is approved.

The code does not apply to installations in manufactured homes built to federal standards, except for connections to the utility.

Violations may result in stop-work orders, fines, and required correction of the installation.

A person may not perform plumbing work for compensation without a license; the license must be issued by the department.

Apprentice registration requires an application and an employer sponsor; the apprentice must be enrolled in a training program.

The journeyman examination covers the plumbing code, practical knowledge, and safety; a passing score is required for licensure.

The master examination covers code, business, and supervision; a master license is required to own a plumbing business.

A license is not transferable; a licensee must notify the department of a change of address or employment.

The department may require a criminal background check and may deny a license for certain offenses.

Licenses expire on a set date and must be renewed; continuing education hours must be completed before renewal.

Example: a single-family home with 2 water closets, 2 lavatories, 1 bathtub, 1 shower, 1 kitchen sink, and 1 washing machine totals 6 DFU for drainage.

Water supply for the same home totals about 14.5 WSFU; the service must be sized for the peak demand in gallons per minute.

A 1-inch water service is typically adequate for a single-family home; larger demands require a larger service.

The building drain must be sized for the total DFU; a 3-inch building drain carries up to 42 DFU at 1/8 inch per foot.

A 4-inch building drain carries up to 216 DFU at 1/8 inch per foot; the slope and size must be selected together.

Vent sizing depends on the fixture units served; a 1-1/2 inch vent is the minimum for a water closet.

The water heater must be sized for the peak hot water demand; a 40-gallon tank is typical for a small home.

A water heater must be installed with a temperature and pressure relief valve; the discharge pipe must terminate within 6 inches of the floor or at a safe point.

A water heater must be seismically restrained where required; in Montana, freeze protection and venting are the primary concerns.

A water heater must be vented to the outdoors; a draft hood or power vent must be installed per the manufacturer's instructions.

A water heater installed in a garage must be elevated so the ignition source is at least 18 inches above the floor.

A thermal expansion tank is required where a backflow preventer creates a closed system.

A water heater must be accessible for service and inspection; clearance to combustibles must be maintained.

A tankless water heater must be sized for the peak flow and temperature rise; the gas supply must be sized for the input rating.

A fixture unit is a measure of the probable discharge into the drainage system by a fixture; it is based on the fixture's flow rate and duration.

A trap seal is the vertical distance between the crown weir and the top of the trap dip; it must be between 2 and 4 inches.

A vent is a pipe that provides air to the drainage system; a stack is a vertical pipe that carries waste or soil.

A building drain is the lowest pipe of the drainage system; a building sewer is the pipe from the building drain to the public sewer.

A cleanout is an access opening for clearing stoppages; it must be accessible and have a removable cover.

A backflow preventer is a device that prevents the reverse flow of water; it must be approved for the application.

A potable water supply is water that is safe for drinking; it must be protected from contamination by backflow or cross-connection.

The Montana plumbing statutes are found in Title 37, Chapter 69 of the Montana Code Annotated; the department administers them.

The statutes define plumbing work, licensing requirements, and enforcement authority.

The department may adopt rules to implement the statutes, including the plumbing code and licensing procedures.

The statutes provide for penalties for unlicensed work, including fines and injunctions.

The statutes require that plumbing work be performed by a licensed plumber or a registered apprentice under supervision.

The statutes authorize the department to inspect plumbing work and require corrections.

The statutes provide for reciprocity with other states that have comparable licensing requirements.

Each fixture must have a trap; a trap must be of the type and size specified in the code.

A trap must be installed level and must have a cleanout if it is not accessible.

A trap may not be double-trapped; two fixtures may not share a trap unless listed as a combination fixture.

A trap arm must be installed with a slope of 1/4 inch per foot and must not exceed the allowed length.

A vent must be installed on each trap; a vent may be a common vent or a wet vent if permitted.

A vent must terminate outdoors and must not be obstructed; a vent cap must be installed.

A vent must be sized for the fixture units served; an undersized vent can cause trap seal loss.

Drainage piping must be installed with a slope of 1/4 inch per foot for 2-1/2 inch and smaller, and 1/8 inch per foot for 3 inch and larger.

Drainage piping must be supported at intervals per material; plastic at 4 feet, cast iron at 5 feet, copper at 10 feet.

Drainage piping must be protected from freezing; in Montana, insulation and heat tracing may be required.

A building drain must be installed below the building or in a crawl space; it must be accessible for inspection.

A cleanout must be installed at the base of each stack and at the end of each horizontal drain.

A backwater valve must be installed where the building drain is below the public sewer.

A drainage system must be tested with water or air before it is concealed.

A water closet must have at least 15 inches from the centerline to a side wall and 21 inches in front of the bowl.

A lavatory must have at least 15 inches from the centerline to a side wall and 21 inches in front.

A bathtub must have at least 15 inches from the centerline to a side wall and 21 inches in front.

A shower must have at least 15 inches from the centerline to a side wall and 21 inches in front.

A kitchen sink must have at least 15 inches from the centerline to a side wall and 21 inches in front.

A floor drain must be accessible and must have a strainer; it must not be installed under a fixture.

A fixture must be accessible for service; a fixture installed in a closet or cabinet must have a removable panel.

Continuing education is required for license renewal; the number of hours is set by department rule.

Approved topics include code updates, safety, and technical training.

A licensee must keep records of continuing education and provide them on request.

Failure to complete continuing education may result in a late fee or license suspension.

The department may audit continuing education records and require proof of completion.

Continuing education must be completed before the license expiration date.

Some courses may be offered online if approved by the department.

WSFU values are assigned per fixture type; a water closet is 2.5, a lavatory is 1, a bathtub is 1.4, a shower is 1.4, and a kitchen sink is 1.4.

A washing machine is 1.4 WSFU; a laundry tub is 1.4 WSFU.

A hose bibb is 2.5 WSFU; a sill cock is 2.5 WSFU.

The total WSFU is converted to gallons per minute using the supply fixture unit table.

The service and meter must be sized for the peak demand plus pressure loss.

A minimum of 8 psi residual pressure is required at the fixture outlet.

The developed length of pipe and elevation loss must be included in the sizing calculation.

Water supply piping must be installed with a minimum cover and protected from freezing.

Water supply piping must be tested at working pressure or 100 psi for 1 hour.

Water supply piping must be protected from backflow by an air gap or approved device.

Water supply piping must be sized for the peak demand plus pressure loss.

Water supply piping must be supported at intervals per material; copper at 10 feet, plastic at 4 feet.

Water supply piping must be insulated where required to prevent condensation or freezing.

Water supply piping must be installed with valves for shutoff and isolation.

A permit is required before installing, altering, repairing, or replacing a plumbing system.

A permit is not required for minor repairs such as stopping leaks, clearing stoppages, or replacing exposed fixture fittings.

A permit application must include plans, specifications, and the name of the licensed contractor.

Work may not begin until the permit is issued.

The code official may revoke a permit for false statements or noncompliance.

A certificate of occupancy may not be issued until the plumbing final inspection is approved.

Violations may result in stop-work orders, fines, and required corrections.

A journeyman plumber may work only under the supervision of a master plumber.

A master plumber is required to contract for plumbing work and obtain permits.

An apprentice must work under the direct supervision of a licensed journeyman or master plumber.

The supervision ratio for apprentices is set by department rule.

A journeyman may not supervise an apprentice unless authorized by rule.

A master plumber is responsible for the work performed under their license.

Violations of supervision requirements may result in license discipline.

Drainage fixture unit values are listed in the code table; use the correct table for the fixture type.

Water supply fixture unit values are listed in a separate table; use the correct table for the fixture type.

The total DFU determines the drainage pipe size and slope.

The total WSFU determines the water supply pipe size and meter size.

Fixture units are cumulative; add the values for all fixtures on the system.

A fixture unit is based on the probable discharge and duration of use.

The code tables must be used as published; do not estimate fixture units.

A vent must terminate outdoors at least 6 inches above the roof.

A vent must be at least 10 feet from any window, door, or air intake, or 2 feet above such openings.

A vent must be sized for the fixture units served.

A vent must be installed on each trap unless a common vent or wet vent is permitted.

A wet vent must be sized and installed per the code.

A dry vent may not be used as a drain.

A vent must not be obstructed and must have an approved vent cap.

Rough-in inspection must be approved before piping is concealed.

The inspector may require a water or air test on any portion of the system.

Final inspection requires all fixtures installed, traps primed, and water heater operational.

The inspector may require corrections before approving the work.

A stop-work order may be issued for work without a permit or noncompliant work.

A certificate of occupancy may not be issued until the final inspection is approved.

Inspections must be requested at the required stages.

The department may investigate complaints and issue citations for violations.

The department may suspend or revoke a license for violations of the statutes or rules.

Unlicensed work may require removal and reinstallation at the owner's expense.

Fines may be imposed for unlicensed work or code violations.

The department may seek an injunction to stop unlicensed work.

A licensee must notify the department of a change of address or employment.

A license is not transferable.

Water closets must not exceed 1.6 gallons per flush.

Urinals must not exceed 1.0 gallon per flush.

Showerheads must not exceed 2.5 gallons per minute at 80 psi.

Lavatory faucets must not exceed 2.2 gallons per minute.

Kitchen faucets must not exceed 2.2 gallons per minute.

Multiple showerheads are counted together for the flow limit.

Fixture efficiency standards are set by federal law and adopted by the code.

Solvent cement must be used for PVC and CPVC joints; the cement must be listed for the application.

Lead-free solder or press fittings must be used for copper joints.

Mechanical couplings must be listed for the application.

No lead-based solder is permitted for potable water.

Joints must be installed per the manufacturer's instructions.

Dissimilar metals must be separated by dielectric fittings.

Joints must be tested for leaks before concealment.

An alternate material or method may be approved if it is equivalent in quality, strength, effectiveness, fire resistance, durability, and safety.

The code official has authority to approve alternate materials and methods.

The code official may require tests to verify compliance.

Unlisted materials may not be installed.

All materials must be listed and labeled by an approved agency.

The code official may interpret the code and require corrections.

Alternate materials must be approved before installation.

Reciprocity may be available for licensees from other states with comparable requirements.

The department reviews reciprocity applications and may require an examination.

A licensee must provide proof of licensure and experience.

Reciprocity is subject to department approval.

The department may impose additional requirements for reciprocity.

Reciprocity does not exempt a licensee from Montana statutes and rules.

A licensee must comply with Montana continuing education requirements.

Grease interceptors are required for commercial kitchens and fixtures discharging grease-laden waste.

Grease interceptors are sized by flow rate and retention time.

Indirect waste connections are required for food service sinks, sterilizers, and dishwashers.

Indirect waste must discharge through an air gap.

An air gap must be at least twice the diameter of the waste pipe.

Indirect waste must not be connected directly to the drainage system.

Grease interceptors must be accessible for cleaning.

Backflow prevention is required at all connections to fixtures and appliances.

An air gap is the preferred backflow prevention method.

An approved backflow prevention device must be installed where an air gap is not possible.

Backflow preventers must be tested annually where required.

A cross-connection must be eliminated or protected by an approved device.

Backflow prevention devices must be accessible for testing and service.

A thermal expansion tank is required where a backflow preventer creates a closed system.

Chapter 4 covers fixtures, fixture clearances, and fixture units.

Chapter 6 covers water supply and sizing.

Chapter 7 covers sanitary drainage.

Chapter 8 covers vents.

Chapter 9 covers traps and cleanouts.

Chapter 10 covers joints and connections.

The code must be used with local amendments and the Montana Plumbing Code.

A licensee must display their license or carry it and provide it on request.

A license is not transferable.

A licensee must notify the department of a change of address or employment.

A licensee must comply with continuing education requirements.

A licensee must comply with the plumbing code and statutes.

A licensee must obtain permits before work begins.

A licensee must request inspections at required stages.

A water heater must be equipped with a temperature and pressure relief valve.

The relief valve discharge pipe must terminate within 6 inches of the floor or at a safe point.

A water heater in a garage must be elevated so the ignition source is at least 18 inches above the floor.

A thermal expansion tank is required where a backflow preventer creates a closed system.

A water heater must be vented to the outdoors.

A water heater must be accessible for service and inspection.

A tankless water heater must be sized for the peak flow and temperature rise.

Each fixture must have a trap.

A trap must be installed level and must have a cleanout if it is not accessible.

A trap may not be double-trapped.

A trap seal must be between 2 and 4 inches deep.

A trap arm must be installed with a slope of 1/4 inch per foot.

A trap arm may not exceed the allowed length for the pipe size.

A trap must be protected by a vent.

Concealed slip joints are prohibited.

Direct connections between potable water and drainage are prohibited.

Fixtures installed in rooms lacking required clearances and ventilation are prohibited.

Unlisted materials are prohibited.

Lead-based solder is prohibited for potable water.

Double-trapping is prohibited.

A dry vent used as a drain is prohibited.

An apprentice must be registered with the department.

An apprentice must work under the direct supervision of a licensed journeyman or master plumber.

An apprentice must be enrolled in a training program.

Apprentice hours are tracked toward journeyman eligibility.

The supervision ratio for apprentices is set by department rule.

An apprentice may not perform plumbing work without supervision.

Apprentice registration requires an employer sponsor.

Add the DFU values for all fixtures on the drainage system.

Add the WSFU values for all fixtures on the water supply system.

Use the total DFU to size the building drain and sewer.

Use the total WSFU to size the water service and meter.

Include the slope of the drainage run in the sizing calculation.

Include the developed length and elevation loss in the water supply sizing.

Use the code tables as published; do not estimate fixture units.

Drainage piping must be supported at intervals per material.

Water supply piping must be supported at intervals per material.

Piping must be protected from freezing.

Piping must be protected from corrosion.

Piping must be protected from physical damage.

Piping must be installed with valves for shutoff and isolation.

Piping must be tested before concealment.

Drainage and vent systems require a water test of 10 ft head or an air test of 5 psi for 15 minutes.

Water supply piping is tested at working pressure or 100 psi for 1 hour.

The inspector may require a test on any portion of the system.

Tests must be conducted before piping is concealed.

Test results must be documented and available for inspection.

A failed test must be corrected and retested.

Testing must be performed in the presence of the inspector where required.

A master plumber license is required to own a plumbing business.

A licensed plumber must provide a written contract for work over the threshold set by statute.

The contract must include scope, price, and timeline.

A plumbing business must comply with state and local licensing requirements.

A plumbing business must carry insurance as required by statute.

A plumbing business must obtain permits before work begins.

A plumbing business must comply with the plumbing code and statutes.

A water closet must have at least 15 inches from the centerline to a side wall and 21 inches in front.

A lavatory must have at least 15 inches from the centerline to a side wall and 21 inches in front.

A bathtub must have at least 15 inches from the centerline to a side wall and 21 inches in front.

A shower must have at least 15 inches from the centerline to a side wall and 21 inches in front.

A kitchen sink must have at least 15 inches from the centerline to a side wall and 21 inches in front.

A fixture must be accessible for service.

A fixture installed in a closet or cabinet must have a removable panel.

Cleanouts are required at the base of each stack.

Cleanouts are required at the end of each horizontal drain.

Cleanouts are required at intervals not exceeding 100 feet in horizontal runs.

Cleanouts must be accessible and have a removable cover.

Cleanouts must be sized per the code.

Cleanouts must be installed with a watertight seal.

Cleanouts must be tested for leaks.

A vent must terminate outdoors at least 6 inches above the roof.

A vent must be at least 10 feet from any window, door, or air intake, or 2 feet above such openings.

A vent must have an approved vent cap.

A vent must not be obstructed.

A vent must be sized for the fixture units served.

A vent must be installed on each trap unless a common vent or wet vent is permitted.

A dry vent may not be used as a drain.

The department adopts the plumbing code by reference.

The current edition and any amendments are published in the administrative rules.

Local jurisdictions may adopt additional requirements but may not be less restrictive than the state code.

The Montana Plumbing Code controls over outdated study materials.

The department may amend the code by rule.

The code must be used with local amendments.

The code official has authority to interpret the code.

A backwater valve is required where the building drain is below the level of the public sewer.

A backwater valve is required where flooding is possible.

A floor drain must have a trap and a strainer.

A floor drain in a food service area must be sized for the expected flow.

A floor drain must not be installed under a fixture.

A floor drain must be accessible for cleaning.

A floor drain must be tested for leaks.

Shower and tub/shower valves must be pressure-balancing or thermostatic.

The maximum water temperature at the fixture must be limited to 120 degrees F.

A water heater must be equipped with a temperature and pressure relief valve.

The relief valve discharge pipe must terminate within 6 inches of the floor or at a safe point.

Water hammer arrestors are required where quick-closing valves can create excessive pressure.

A thermal expansion tank is required where a backflow preventer creates a closed system.

Piping must be protected from excessive pressure.

A fixture unit is a measure of the probable discharge into the drainage system by a fixture.

Fixture units are based on the fixture's flow rate and duration.

DFU values are used for drainage sizing.

WSFU values are used for water supply sizing.

Fixture units are cumulative.

The code tables must be used as published.

Do not estimate fixture units.

The journeyman examination covers the plumbing code, practical knowledge, and safety.

A passing score is required for licensure.

The master examination covers code, business, and supervision.

The department may require a criminal background check.

The department may deny a license for certain offenses.

Examination results are valid for a limited time.

A licensee must comply with continuing education requirements.

Fixtures must be listed and comply with an approved standard.

Water closets must not exceed 1.6 gallons per flush.

Urinals must not exceed 1.0 gallon per flush.

Showerheads must not exceed 2.5 gallons per minute at 80 psi.

Lavatory faucets must not exceed 2.2 gallons per minute.

Kitchen faucets must not exceed 2.2 gallons per minute.

Multiple showerheads are counted together for the flow limit.

Drainage pipe must have a slope of 1/4 inch per foot for 2-1/2 inch and smaller.

Drainage pipe must have a slope of 1/8 inch per foot for 3 inch and larger.

The building drain must be sized for the total DFU.

A 3-inch building drain carries up to 42 DFU at 1/8 inch per foot.

A 4-inch building drain carries up to 216 DFU at 1/8 inch per foot.

The slope and size must be selected together.

The building sewer must be sized for the total DFU.

A trap seal is the vertical distance between the crown weir and the top of the trap dip.

A trap seal must be between 2 and 4 inches deep.

A vent is a pipe that provides air to the drainage system.

A stack is a vertical pipe that carries waste or soil.

A building drain is the lowest pipe of the drainage system.

A building sewer is the pipe from the building drain to the public sewer.

A cleanout is an access opening for clearing stoppages.

Licenses expire on a set date and must be renewed.

Continuing education hours must be completed before renewal.

Late renewal may require a penalty or reexamination.

A licensee must notify the department of a change of address or employment.

A license is not transferable.

A licensee must keep records of continuing education.

The department may audit continuing education records.

A single-family home with 2 water closets, 2 lavatories, 1 bathtub, 1 shower, 1 kitchen sink, and 1 washing machine totals 6 DFU for drainage.

Water supply for the same home totals about 14.5 WSFU.

A 1-inch water service is typically adequate for a single-family home.

A 40-gallon water heater is typical for a small home.

The water heater must be sized for the peak hot water demand.

The building drain must be sized for the total DFU.

The vent must be sized for the fixture units served.

PVC is permitted for drainage and vent systems but not for hot water distribution.

CPVC is permitted for hot and cold water.

PEX is permitted for water distribution where listed.

Copper types K, L, and M are permitted for water supply.

Type M copper is not permitted for underground installation.

Galvanized steel must not be used with copper in a way that causes galvanic corrosion.

No lead content is permitted in pipe, solder, or flux used for potable water.

The code official has authority to approve alternate materials and methods.

An alternate material may be approved if it is equivalent in quality, strength, effectiveness, fire resistance, durability, and safety.

The code official may require tests to verify compliance.

Unlisted materials may not be installed.

All materials must be listed and labeled by an approved agency.

The code official may interpret the code and require corrections.

Alternate materials must be approved before installation.

Plumbing permits must be obtained from the local jurisdiction before work begins.

Inspections must be requested at required stages: rough-in and final.

A permit application must include plans and the name of the licensed contractor.

Work may not begin until the permit is issued.

The code official may revoke a permit for false statements or noncompliance.

A certificate of occupancy may not be issued until the final inspection is approved.

Violations may result in stop-work orders and fines.

Drainage pipe sizing uses the DFU table with slope limitations.

Smaller pipe sizes carry fewer fixture units.

The allowable load decreases as slope decreases.

A 3-inch building drain carries up to 42 DFU at 1/8 inch per foot.

A 4-inch building drain carries up to 216 DFU at 1/8 inch per foot.

The slope and size must be selected together.

The building sewer must be sized for the total DFU.

Water supply sizing uses total WSFU from the building supply tables.

The meter and service must be sized for the total demand plus pressure loss.

A minimum of 8 psi residual pressure is required at the fixture outlet.

The developed length of pipe and elevation loss must be included in the sizing calculation.

A 1-inch water service is typically adequate for a single-family home.

Larger demands require a larger service.

The water heater must be sized for the peak hot water demand.

Fixtures must be accessible for service.

No plumbing fixture may be installed unless it is listed and complies with an approved standard.

Fixtures must be installed with required clearances.

Fixtures must be installed in rooms with required ventilation.

Fixtures must be installed with traps and vents.

Fixtures must be installed with backflow protection.

Fixtures must be tested for leaks.

The supervision ratio for apprentices is set by department rule.

A journeyman may not supervise an apprentice unless authorized by rule.

A master plumber is responsible for the work performed under their license.

An apprentice must work under the direct supervision of a licensed journeyman or master plumber.

A journeyman may work only under the supervision of a master plumber.

A master plumber is required to contract for plumbing work and obtain permits.

Violations of supervision requirements may result in license discipline.

Water closet DFU is 3.

Lavatory DFU is 1.

Bathtub DFU is 2.

Shower DFU is 2.

Kitchen sink DFU is 2.

Floor drain DFU is 2.

Washing machine DFU is 2.

The vent must not be smaller than the drain it serves in most cases.

A 1-1/2 inch vent is the minimum for a water closet.

A 1-1/4 inch vent is the minimum for other fixtures.

The vent must be sized for the fixture units served.

An undersized vent can cause trap seal loss.

A vent must terminate outdoors.

A vent must have an approved vent cap.

A plumbing system must be designed by a licensed engineer when the occupancy or size exceeds the prescriptive limits of the code.

The code official may require engineering calculations for complex systems.

The system must be designed for the expected load.

The system must be designed for the available pressure.

The system must be designed for freeze protection.

The system must be designed for backflow prevention.

The system must be designed for accessibility.

Plumbing work includes the installation, alteration, repair, and replacement of plumbing systems.

A journeyman plumber is licensed to perform plumbing work under a master plumber.

A master plumber is licensed to contract for plumbing work and supervise journeymen.

An apprentice is registered and works under supervision.

A plumbing contractor is a business licensed to perform plumbing work.

The department administers licensing and enforcement.

The statutes and rules define the scope of plumbing work.

WSFU values are converted to gallons per minute using the supply fixture unit table.

The total WSFU determines the water supply pipe size.

The total DFU determines the drainage pipe size.

The meter and service must be sized for the peak demand.

The developed length and elevation loss must be included.

A minimum of 8 psi residual pressure is required at the fixture outlet.

The water heater must be sized for the peak hot water demand.

Drainage and vent systems require a water test of 10 ft head or an air test of 5 psi for 15 minutes.

Water supply piping is tested at working pressure or 100 psi for 1 hour.

Tests must be conducted before piping is concealed.

Test results must be documented and available for inspection.

A failed test must be corrected and retested.

The inspector may require a test on any portion of the system.

Testing must be performed in the presence of the inspector where required.

Local jurisdictions may adopt additional requirements.

Local requirements may not be less restrictive than the state code.

The more restrictive provision governs where codes differ.

The Montana Plumbing Code controls over outdated study materials.

The department adopts the plumbing code by reference.

The current edition and amendments are published in the administrative rules.

The code official has authority to interpret the code.

A plumbing business must carry insurance as required by statute.

A licensed plumber must provide a written contract for work over the threshold set by statute.

The contract must include scope, price, and timeline.

A plumbing business must comply with state and local licensing requirements.

A plumbing business must obtain permits before work begins.

A plumbing business must comply with the plumbing code and statutes.

A plumbing business must maintain records of work performed.

Use the drainage fixture unit table for drainage sizing.

Use the water supply fixture unit table for water supply sizing.

Do not use one table for the other purpose.

Fixture units are cumulative.

The code tables must be used as published.

Do not estimate fixture units.

The total DFU and WSFU determine pipe sizes.

Water supply piping must be protected from freezing.

Drainage piping must be protected from freezing.

In Montana, insulation and heat tracing may be required.

Piping must be installed with a minimum cover.

Piping must be protected from physical damage.

Piping must be protected from corrosion.

Piping must be tested before concealment.

A fixture unit is a measure of the probable discharge into the drainage system by a fixture.

Fixture units are based on the fixture's flow rate and duration.

DFU values are used for drainage sizing.

WSFU values are used for water supply sizing.

Fixture units are cumulative.

The code tables must be used as published.

Do not estimate fixture units.

The department may investigate complaints against licensees.

The department may issue citations for violations.

The department may suspend or revoke a license.

A licensee must respond to department inquiries.

A licensee must provide records on request.

A licensee must comply with the statutes and rules.

Violations may result in fines and license discipline.

A water closet is 3 DFU and 2.5 WSFU.

A lavatory is 1 DFU and 1 WSFU.

A bathtub is 2 DFU and 1.4 WSFU.

A shower is 2 DFU and 1.4 WSFU.

A kitchen sink is 2 DFU and 1.4 WSFU.

A washing machine is 2 DFU and 1.4 WSFU.

A floor drain is 2 DFU.

Water supply piping must be installed with valves for shutoff and isolation.

A main shutoff valve must be installed near the point of entry.

A valve must be accessible.

A valve must be listed for the application.

A valve must be tested for leaks.

A valve must be protected from freezing.

A valve must be installed per the manufacturer's instructions.

Fixture units are used to size drainage and water supply systems.

DFU values are used for drainage sizing.

WSFU values are used for water supply sizing.

The total DFU determines the drainage pipe size.

The total WSFU determines the water supply pipe size.

The code tables must be used as published.

Do not estimate fixture units.

A plumbing business must maintain records of work performed.

A licensee must keep records of continuing education.

The department may audit records.

A licensee must provide records on request.

Records must be kept for the period set by rule.

Records must be accurate and complete.

Failure to maintain records may result in discipline.

DFU values are used for drainage sizing.

WSFU values are used for water supply sizing.

The total DFU determines the drainage pipe size.

The total WSFU determines the water supply pipe size.

The code tables must be used as published.

Do not estimate fixture units.

The slope and size must be selected together.

Drainage pipe must have a slope of 1/4 inch per foot for 2-1/2 inch and smaller.

Drainage pipe must have a slope of 1/8 inch per foot for 3 inch and larger.

Drainage piping must be supported at intervals per material.

Water supply piping must be supported at intervals per material.

Piping must be protected from freezing.

Piping must be protected from backflow.

Piping must be tested before concealment.

The code applies to new work and to repairs or alterations that affect the system's capacity, safety, or sanitation performance.

Permits are required before work begins.

Inspections must be requested at required stages.

Materials must be approved and identified.

Fixtures must be accessible for service.

Systems must be tested before concealment.

The code official has authority to interpret the code.

A license is required to perform plumbing work for compensation.

A master plumber is required to contract for plumbing work.

An apprentice must work under supervision.

Continuing education is required for renewal.

Permits must be obtained before work begins.

Inspections must be requested at required stages.

The department may investigate complaints and issue penalties.

DFU values are used for drainage sizing.

WSFU values are used for water supply sizing.

The total DFU determines the drainage pipe size.

The total WSFU determines the water supply pipe size.

The code tables must be used as published.

Do not estimate fixture units.

The slope and size must be selected together.

Drainage pipe must have a slope of 1/4 inch per foot for 2-1/2 inch and smaller.

Drainage pipe must have a slope of 1/8 inch per foot for 3 inch and larger.

Drainage piping must be supported at intervals per material.

Water supply piping must be supported at intervals per material.

Piping must be protected from freezing.

Piping must be protected from backflow.

Piping must be tested before concealment.

The code applies to new work and to repairs or alterations that affect the system's capacity, safety, or sanitation performance.

Permits are required before work begins.

Inspections must be requested at required stages.

Materials must be approved and identified.

Fixtures must be accessible for service.

Systems must be tested before concealment.

The code official has authority to interpret the code.

A license is required to perform plumbing work for compensation.

A master plumber is required to contract for plumbing work.

An apprentice must work under supervision.

Continuing education is required for renewal.

Permits must be obtained before work begins.

Inspections must be requested at required stages.

The department may investigate complaints and issue penalties.