ICC Master Plumber - G24-N Exam Prep Guide

The ICC Master Plumber - G24-N examination is designed for experienced plumbing professionals preparing to demonstrate advanced knowledge of plumbing regulations, fixtures, water heaters, water distribution, sanitary drainage, venting, traps, interceptors, storm drainage, system design, plan reading, testing, and code-compliant supervision.

The ICC Master Plumber - G24-N exam prep collection includes a books and courses rental package, professionally highlighted and tabbed study material, flexible online exam preparation, and a standard exam book package.

This guide explains the available preparation options, examination details, major plumbing subjects, calculation topics, code-navigation methods, and practical strategies for preparing for the G24-N examination.

Available G24-N Exam Prep Packages

• ICC Master Plumber - G24-N - Books & Courses Rental Package: $540.00 sale price, reduced from $840.00
• ICC Master Plumber - G24-N Highlighted & Tabbed Book Package: $245.00 sale price, reduced from $445.00
• ICC Master Plumber - G24-N - Online Exam Prep: $295.00 sale price, reduced from $395.00
• ICC Master Plumber - G24-N Exam Book Package: $129.00 sale price, reduced from $229.00

The rental package combines temporary book access with structured online preparation. The highlighted and tabbed package supports faster code navigation. The online course is suitable for candidates who already own the correct reference, while the exam book package supports independent preparation.

Books & Courses Rental Package

The ICC Master Plumber - G24-N Books & Courses Rental Package combines access to the assigned plumbing reference with organized online exam preparation.

The package is listed at a sale price of $540.00, reduced from the regular price of $840.00.

This package may be appropriate for candidates who:

• Need the exam book and online course together
• Do not currently own the approved reference
• Want an organized master plumber study plan
• Need help navigating plumbing tables and code sections
• Want practice with sizing calculations and plan reading
• Prefer combining lessons, books, and practice questions

Candidates should review the current product listing for course access, rental periods, shipping details, deposit requirements, and return instructions.

Highlighted & Tabbed Book Package

The ICC Master Plumber - G24-N Highlighted & Tabbed Book Package provides professionally organized study material for candidates who want to begin preparing without marking every section themselves.

The package is listed at a sale price of $245.00, reduced from the regular price of $445.00.

The prepared reference may help candidates locate:

• Plumbing definitions and general regulations
• Fixture and water heater requirements
• Water-supply sizing tables
• Sanitary drainage provisions
• Plumbing vent requirements
• Trap, interceptor, and separator provisions
• Storm drainage requirements
• Plan-reading and referenced-standard information

Highlighted and tabbed books can improve navigation, but candidates must still understand how to interpret tables, definitions, exceptions, and installation requirements.

Online Exam Prep

The ICC Master Plumber - G24-N Online Exam Prep course provides flexible, self-paced preparation for candidates who already own the correct reference or plan to purchase it separately.

The course is listed at a sale price of $295.00, reduced from the regular price of $395.00.

Online preparation may help candidates:

• Review master-level plumbing subjects in a logical order
• Practice water and drainage calculations
• Improve plumbing code navigation
• Review plan-reading and system-design questions
• Identify weak knowledge areas
• Complete timed practice questions
• Study around an active plumbing schedule

The course is most effective when candidates use the approved plumbing code while completing lessons and practice questions.

Exam Book Package

The ICC Master Plumber - G24-N Exam Book Package provides the printed reference associated with the examination for independent preparation.

The package is listed at a sale price of $129.00, reduced from the regular price of $229.00.

This package may be appropriate for candidates who:

• Prefer independent book-based study
• Want to own the plumbing code reference
• Already understand many advanced plumbing subjects
• Want to create a personalized tab and highlighting system
• Already have separate instruction or practice questions
• Need the reference for continued professional use

What Is the ICC G24-N Examination?

The G24-N examination is the ICC National Standard Master Plumber examination. Participating jurisdictions may use it as part of a master plumber, plumbing contractor, qualifying individual, or supervisory licensing process.

The examination includes 100 multiple-choice questions and has a four-hour time limit. Candidates must earn at least 70 percent to pass.

The examination is open book, subject to current ICC rules for approved references, permanent tabs, highlighting, handwritten notes, inserted materials, and book condition.

Passing G24-N does not automatically issue a master plumber license. Candidates must also satisfy the experience, application, insurance, business, financial, and supervisory requirements established by the applicable licensing authority.

G24-N Exam Reference

The current examination information identifies the following primary reference:

• International Plumbing Code, 2018 Edition

The International Plumbing Code covers plumbing administration, materials, fixtures, water heaters, water supply and distribution, sanitary drainage, venting, traps, interceptors, separators, storm drainage, testing, and related system-design requirements.

Candidates should confirm the approved edition before registering because examination references and jurisdictional code cycles can change.

G24-N Examination Content

The current examination outline distributes questions across these major areas:

• Administration and General Regulations: 46%
• Plumbing Fixtures: 14%
• Water Supply and Distribution: 11%
• Sanitary Drainage: 11%
• Plumbing Vent Requirements: 8%
• Traps, Interceptors, and Separators: 8%
• Storm Drainage: 2%

Administration and general regulations represent a large portion of the exam, but candidates should prepare across the complete content outline.

Confirm Local Master Plumber Requirements

Before purchasing materials or scheduling the examination, candidates should verify:

• Whether the licensing authority accepts G24-N
• The scope of the master plumber classification
• The required International Plumbing Code edition
• The current approved reference list
• The question count, testing time, and passing score
• Rules for tabs, highlighting, and notes
• Required journeyman and supervisory experience
• Application and examination fees
• Insurance and bonding requirements
• Business or qualifying-party requirements
• License renewal requirements
• Continuing-education requirements

What Does a Master Plumber Do?

A master plumber may design, install, alter, repair, inspect, test, and supervise plumbing systems within the scope permitted by the applicable licensing authority.

Common responsibilities may include:

• Reviewing plumbing plans and specifications
• Designing water-distribution systems
• Sizing sanitary drainage and vent systems
• Planning storm drainage systems
• Selecting approved piping materials
• Reviewing fixture and water heater installations
• Specifying backflow-prevention methods
• Supervising journeymen and apprentices
• Coordinating permits and inspections
• Testing completed plumbing systems
• Correcting unsafe or noncompliant installations
• Maintaining project and inspection records

The exact scope of work depends on state and local licensing rules.

Administration and General Regulations

Master plumber candidates should understand how plumbing projects move through plan review, permitting, inspection, testing, correction, and final approval.

Study subjects may include:

• Permit requirements
• Construction documents
• Required inspections
• Approved materials and methods
• Alternative materials
• Protection of piping
• Equipment access
• System testing
• Unsafe conditions
• Code official authority
• Installer and permit-holder responsibilities
• Referenced standards

Plumbing Plans and System Design

Master-level candidates may need to interpret plumbing plans, specifications, fixture schedules, riser diagrams, isometric drawings, and construction details.

Plan-reading subjects may include:

• Domestic water plans
• Sanitary drainage layouts
• Vent riser diagrams
• Storm drainage plans
• Pipe sizes and slopes
• Fixture schedules
• Valve and equipment locations
• Cleanout locations
• Developed piping lengths
• Plan symbols and abbreviations
• Specification requirements

Candidates should connect information shown on plans with the applicable plumbing code provisions.

Plumbing Materials and Joints

Plumbing materials and joining methods must be approved for the system, pressure, temperature, location, and installation method.

Materials may include:

• Copper and copper-alloy piping
• Cast-iron soil pipe
• Galvanized steel pipe
• Stainless steel piping
• PVC and CPVC piping
• ABS piping
• PEX tubing
• Polyethylene piping
• Approved transition fittings

Joining methods may include soldering, brazing, threading, welding, solvent cement, pressing, compression, flaring, mechanical joints, and heat fusion.

Pipe Support and Protection

Plumbing piping must be supported and protected to prevent sagging, movement, corrosion, joint stress, and physical damage.

Important subjects may include:

• Horizontal support spacing
• Vertical support
• Support near changes in direction
• Protection through framing members
• Protective plates
• Expansion and contraction
• Protection from freezing
• Corrosion protection
• Underground bedding and backfill
• Protection from vehicles and equipment

Plumbing Fixtures

Fixture requirements address approved products, installation, supports, clearances, water connections, drainage connections, and accessibility.

Common fixtures include:

• Water closets
• Urinals
• Lavatories
• Kitchen and service sinks
• Bathtubs and showers
• Drinking fountains
• Clothes-washing machines
• Floor drains
• Emergency fixtures
• Commercial food-service fixtures

Candidates should review fixture-unit values, minimum fixture quantities, clearances, trap requirements, supports, waste connections, and water-supply connections.

Required Number of Fixtures

Some questions may require candidates to determine the minimum number of fixtures for a building or occupancy.

Important considerations include:

• Occupancy classification
• Occupant load
• Male and female distribution
• Water closets and urinals
• Lavatories
• Drinking fountains
• Service sinks
• Separate-facility requirements
• Fixture substitutions
• Table notes and exceptions

Fixture Clearances and Accessibility

Fixtures must have sufficient space for use, cleaning, maintenance, and accessibility.

Study areas may include:

• Water closet clearances
• Urinal spacing
• Lavatory clearances
• Shower dimensions
• Bathtub installation
• Fixture supports
• Wall-hung fixture carriers
• Access to concealed connections
• Accessible fixture heights
• Protection from physical damage

Water Heaters

Water heater questions may involve installation location, capacity, temperature control, pressure protection, drainage, accessibility, and energy-related requirements.

Candidates should review:

• Temperature and pressure relief valves
• Relief discharge piping
• Drain pans
• Cold-water shutoff valves
• Thermal expansion control
• Expansion tanks
• Tempering valves
• Garage installation
• Access for service
• Protection from physical damage

Temperature and Pressure Relief

Storage water heaters require protection against excessive temperature and pressure.

Study subjects may include:

• Relief valve location
• Valve capacity and rating
• Discharge pipe size
• Approved discharge materials
• Termination location
• Air-gap requirements
• Prohibited valves and restrictions
• Protection from freezing
• Drainage to an approved location

Water Supply and Distribution

Water-distribution systems must deliver potable water at suitable flow and pressure to every required fixture and appliance.

Study subjects may include:

• Water service piping
• Water-distribution piping
• Water-supply fixture units
• Developed piping length
• Available supply pressure
• Elevation pressure loss
• Friction and equipment losses
• Pressure-reducing valves
• Water hammer control
• Thermal expansion
• Hot-water distribution
• Recirculation systems

Water Pipe-Sizing Calculations

Master-level water pipe sizing may require candidates to evaluate fixture load, developed length, available pressure, elevation, meter loss, and equipment pressure loss.

A practical sizing process includes:

• Identify all fixtures served
• Determine the water-supply fixture units
• Calculate developed piping length
• Determine available supply pressure
• Calculate elevation pressure loss
• Account for meters, backflow devices, and equipment
• Select the applicable sizing table
• Choose a pipe size with adequate capacity

Candidates should identify whether the question concerns the water service, building supply, riser, branch, or individual fixture connection.

Water Pressure and Booster Systems

Water pressure must be sufficient to operate fixtures while remaining within safe limits for piping, valves, and equipment.

Study considerations may include:

• Minimum fixture pressure
• Maximum static pressure
• Pressure-reducing valves
• Elevation loss
• Friction loss
• Booster pumps
• Pressure tanks
• Low-pressure conditions
• Water hammer
• Thermal expansion

Backflow Prevention

Backflow prevention protects potable water from contamination caused by backsiphonage or backpressure.

Candidates should review:

• Air gaps
• Atmospheric vacuum breakers
• Pressure vacuum breakers
• Reduced-pressure-principle assemblies
• Double-check assemblies
• Hose connection vacuum breakers
• Required device locations
• Degree of hazard
• Installation clearances
• Testing and accessibility

The type of potential contamination and the degree of hazard determine the required protection.

Hot-Water Distribution

Hot-water systems must provide suitable temperatures while controlling heat loss, scald hazards, and excessive pressure.

Study subjects may include:

• Hot-water pipe sizing
• Temperature limitations
• Tempering valves
• Recirculation systems
• Pipe insulation
• Dead-end lengths
• Thermal expansion
• Fixture temperature controls
• Scald protection
• Energy-conservation requirements

Sanitary Drainage Systems

Sanitary drainage systems carry wastewater from fixtures to the building sewer or another approved disposal point.

Important subjects include:

• Drainage fixture units
• Fixture drains
• Horizontal branches
• Vertical stacks
• Building drains
• Building sewers
• Pipe sizing and slope
• Changes in direction
• Cleanouts
• Sumps and ejectors
• Special waste systems
• System testing

Drainage Fixture Units and Pipe Sizing

Drainage fixture units represent the probable discharge load produced by plumbing fixtures.

Candidates may need to:

• Determine individual fixture-unit values
• Add fixture units on branches
• Calculate stack loads
• Calculate building drain loads
• Size building sewers
• Apply required pipe slopes
• Use branch-interval limitations
• Interpret table notes and exceptions

The correct sizing table depends on whether the piping is horizontal, vertical, a stack, a building drain, or a building sewer.

Drainage Pipe Slope

Drainage piping must be installed at a slope that supports effective flow without creating excessive velocity or leaving solids behind.

Candidates should review:

• Minimum slopes by pipe size
• Horizontal drainage branches
• Building drains
• Building sewers
• Changes in slope
• Grading requirements
• Support needed to maintain slope
• Inspection before concealment

Changes in Drainage Direction

Drainage fittings must direct wastewater smoothly and reduce the possibility of blockages.

Study subjects may include:

• Horizontal-to-horizontal changes
• Vertical-to-horizontal changes
• Horizontal-to-vertical changes
• Sanitary tees
• Wyes
• Combination fittings
• Long-turn fittings
• Quarter bends
• Base-of-stack connections
• Prohibited fitting arrangements

Cleanouts

Cleanouts provide access for inspection, cleaning, and removal of drainage obstructions.

Candidates should review:

• Required cleanout locations
• Maximum spacing
• Changes in direction
• Building drain cleanouts
• Building sewer cleanouts
• Stack cleanouts
• Cleanout size
• Required access and clearance
• Protection from physical damage

Sumps and Sewage Ejectors

Fixtures below the level of the gravity building sewer may require a sump and pumping system.

Study subjects may include:

• Sump construction
• Gas-tight covers
• Pump capacity
• Discharge piping
• Check valves
• Shutoff valves
• Vent connections
• Alarm systems
• Access for service
• Emergency power where required

Plumbing Vent Systems

Vent systems protect trap seals and allow drainage systems to operate at atmospheric pressure.

Common venting methods include:

• Individual vents
• Common vents
• Wet vents
• Circuit vents
• Stack vents
• Vent stacks
• Relief vents
• Island fixture vents
• Combination waste and vent systems
• Air admittance valves where permitted

Candidates should identify the venting method before applying sizing and connection requirements.

Vent Sizing and Trap Arms

Vent size may depend on connected drainage fixture units, developed length, and the drainage piping served.

Trap-arm questions may involve:

• Trap-arm pipe size
• Maximum developed length
• Required slope
• Distance from the trap to the vent
• Changes in direction
• Connection to the vented drainage system
• Protection of the trap seal

Candidates should practice locating and applying vent-sizing and trap-arm tables under timed conditions.

Wet Venting and Circuit Venting

Wet and circuit vent systems allow specific drainage piping to provide venting when all required conditions are satisfied.

Candidates should review:

• Permitted fixture groups
• Bathroom-group arrangements
• Pipe sizing
• Fixture connection order
• Horizontal wet venting
• Vertical wet venting
• Circuit vent connections
• Relief vents
• Prohibited arrangements

Vent Termination

Plumbing vents must terminate where sewer gases will not enter the building or create an unsafe condition.

Study areas may include:

• Termination through the roof
• Clearance from windows and doors
• Clearance from air intakes
• Height above the roof
• Protection from frost closure
• Sidewall termination where permitted
• Combining vent terminals
• Protection from physical damage

Traps

Fixture traps maintain a water seal that helps prevent sewer gases from entering occupied spaces.

Important subjects include:

• Required trap locations
• Trap-seal depth
• Trap size
• Trap accessibility
• Prohibited traps
• Double trapping
• Trap primers
• Protection from evaporation
• Integral fixture traps
• Building traps where permitted

Interceptors and Separators

Interceptors and separators remove grease, oil, sand, sediment, lint, solids, and other materials before they enter the drainage system.

Common devices may include:

• Grease interceptors
• Grease traps
• Oil separators
• Sand interceptors
• Lint interceptors
• Hair interceptors
• Food-waste interceptors
• Special-purpose separators

Candidates should review required locations, sizing, access, venting, maintenance, and prohibited connections.

Grease Interceptors

Grease interceptors may be required for commercial kitchens and other operations that discharge fats, oils, or grease.

Study considerations may include:

• Fixtures requiring protection
• Interceptor type
• Flow rate
• Fixture capacity
• Location and accessibility
• Venting
• Flow-control devices
• Maintenance requirements
• Prohibited connections

Storm Drainage

Storm drainage systems remove rainwater from roofs and other approved surfaces.

Study subjects may include:

• Roof drainage areas
• Rainfall rates
• Roof drains
• Gutters
• Leaders and conductors
• Horizontal storm piping
• Secondary drainage
• Overflow drains
• Scuppers
• Discharge locations

Storm Drainage Calculations

Storm drainage sizing may depend on roof area, rainfall rate, pipe slope, gutter size, and conductor capacity.

Candidates should practice:

• Calculating roof drainage areas
• Dividing roofs among multiple drains
• Using rainfall-rate tables
• Sizing roof drains
• Sizing vertical conductors
• Sizing horizontal storm piping
• Evaluating overflow systems
• Sizing gutters and scuppers

Plumbing System Testing

Plumbing systems may require inspection and testing before piping is concealed or placed into service.

Study areas may include:

• Water piping pressure tests
• Drainage and vent tests
• Water tests
• Air tests
• Approved test equipment
• Test pressure and duration
• Isolation of equipment
• Leak inspection
• Repair and retesting
• Inspection documentation

Supervision and Quality Control

A master plumber may be responsible for supervising field personnel and confirming that installations match approved plans and plumbing code requirements.

Quality-control checks may include:

• Correct pipe sizing
• Approved materials and fittings
• Proper support and protection
• Fixture and equipment clearances
• Drainage pipe slopes
• Vent connections
• Backflow protection
• Water heater safety devices
• Cleanout accessibility
• Pressure-test results
• Required permits and inspections

Plumbing Safety

Plumbing work may involve excavation, pressurized systems, hot work, confined spaces, ladders, power tools, and exposure to contaminated systems.

Important safety subjects include:

• Personal protective equipment
• Trenching and excavation safety
• Confined-space awareness
• Hot-work precautions
• Pressure-test safety
• Lockout and tagout
• Ladder safety
• Material handling
• Sanitation and exposure control
• Protection of occupants and property

Code-Book Navigation

An open-book examination still requires fast and accurate reference navigation. Candidates must know where major plumbing subjects are located before exam day.

A practical lookup method includes:

• Read the complete question
• Identify the plumbing system involved
• Select the likely chapter
• Use the table of contents or index
• Locate the complete section, table, or figure
• Review definitions, footnotes, and exceptions
• Confirm that the requirement applies to the stated conditions
• Record difficult topics for additional practice

Candidates should practice using fixture-unit, water-supply, drainage, vent, and storm-drainage tables under timed conditions.

Organizing the G24-N Reference

A practical tab system may include:

• Definitions
• General regulations
• Fixtures
• Water heaters
• Water supply
• Backflow prevention
• Sanitary drainage
• Drainage tables
• Cleanouts
• Vents
• Vent tables
• Traps
• Interceptors
• Storm drainage
• Referenced standards

Candidates should verify current ICC testing rules before adding tabs, highlighting, notes, or other book modifications.

Recommended Study Plan

• Review exam rules and code-book organization
• Study administration and general regulations
• Review approved materials and joining methods
• Study fixtures and water heaters
• Practice water-distribution calculations
• Review water pressure and backflow prevention
• Practice sanitary drainage sizing
• Study cleanout and sump requirements
• Review vent systems and vent sizing
• Study traps, interceptors, and separators
• Practice storm drainage calculations
• Review plumbing plans and isometric drawings
• Complete timed code-navigation exercises
• Review every missed practice question

Which G24-N Package Should You Choose?

• Choose the Books & Courses Rental Package for temporary reference-book access and structured online preparation.
• Choose the Highlighted & Tabbed Book Package for professionally organized study material.
• Choose Online Exam Prep when you already own the correct reference and want guided study.
• Choose the Exam Book Package for independent preparation and permanent book ownership.

FAQ

Q. What is the ICC Master Plumber - G24-N exam?

A. It is an ICC Contractor and Trades examination used by participating jurisdictions to evaluate master-level plumbing, system-design, code-navigation, and supervisory knowledge.

Q. How much does the Books & Courses Rental Package cost?

A. The sale price is $540.00, reduced from the regular price of $840.00.

Q. How much does the Highlighted & Tabbed Book Package cost?

A. The sale price is $245.00, reduced from the regular price of $445.00.

Q. How much does Online Exam Prep cost?

A. The sale price is $295.00, reduced from the regular price of $395.00.

Q. How much does the Exam Book Package cost?

A. The sale price is $129.00, reduced from the regular price of $229.00.

Q. What book is used for G24-N?

A. The current reference is the 2018 International Plumbing Code.

Q. How many questions are on the G24-N examination?

A. The examination currently includes 100 multiple-choice questions.

Q. How much time is allowed?

A. Candidates currently have four hours to complete the examination.

Q. What score is required to pass?

A. Candidates must currently answer at least 70 percent of the questions correctly.

Q. Is the G24-N examination open book?

A. Yes. Candidates may use approved references subject to current ICC testing rules.

Q. What subjects should I study?

A. Study administration, fixtures, water heaters, water distribution, sanitary drainage, venting, traps, interceptors, storm drainage, testing, and plan reading.

Q. Should I practice water pipe-sizing calculations?

A. Yes. Candidates should practice fixture units, developed length, available pressure, elevation loss, equipment losses, and sizing tables.

Q. Should I practice drainage and vent calculations?

A. Yes. Master-level preparation should include drainage fixture units, pipe slopes, stacks, building drains, building sewers, vent sizing, and trap-arm limitations.

Q. Should I study plumbing plans?

A. Yes. Candidates should practice water, drainage, vent, and storm plans, riser diagrams, isometric drawings, and fixture schedules.

Q. Does passing G24-N automatically issue a master plumber license?

A. No. The applicable licensing authority controls experience, applications, insurance, business requirements, fees, and final approval.

Q. Where can I purchase the G24-N packages?

A. The available options can be found in the ICC Master Plumber - G24-N exam prep collection.

Conclusion

The ICC Master Plumber - G24-N examination requires candidates to combine advanced plumbing experience with system-design ability, accurate calculations, efficient code navigation, plan reading, and supervisory understanding.

Important preparation subjects include plumbing administration, fixtures, water heaters, water supply, backflow prevention, sanitary drainage, venting, traps, interceptors, storm drainage, system testing, and quality control.

1 Exam Prep offers a Books & Courses Rental Package, Highlighted & Tabbed Book Package, Online Exam Prep, and Exam Book Package for different preparation needs and budgets.

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Key Takeaways

• G24-N is the ICC National Standard Master Plumber examination.
• The Books & Courses Rental Package sale price is $540.00.
• The Highlighted & Tabbed Book Package sale price is $245.00.
• The Online Exam Prep sale price is $295.00.
• The Exam Book Package sale price is $129.00.
• The examination currently includes 100 questions and a four-hour limit.
• The passing requirement is 70 percent.
• The examination is open book under current testing rules.
• The current reference is the 2018 International Plumbing Code.
• The exam covers plumbing administration, fixtures, water supply, drainage, venting, traps, and storm drainage.
• Passing G24-N does not automatically issue a master plumber license.
• Candidates should verify current examination and jurisdictional requirements before registering.