Free Journeyman Plumber Practice Test
These 36 practice questions are original and unofficial. Questions 1–6 cover trade math and jobsite safety that do not depend on a plumbing-code family. Questions 7–36 use the 2021 International Plumbing Code (IPC). Journeyman exam rules are jurisdiction-specific, so check how plumber exams differ by jurisdiction after you finish.
Practice test: 36 questions with answers
Part 1: Trade fundamentals (any code)
Question 1
Trade math · JP-F01
A horizontal drain is installed at a slope of 1/8 inch per foot over a run of 48 feet. How much lower is the downstream end than the upstream end?
- A. 3 inches
- B. 6 inches
- C. 12 inches
- D. 24 inches
Show answer and explanation — Question 1
Answer: B. 6 inches
Fall = run × slope = 48 ft × 1/8 in/ft = 6 in. 12 in is what you get at 1/4 in/ft, and 3 in is 1/16 in/ft. On the exam, multiply first, then check that your answer is in inches, not feet.
Source: Arithmetic shown above.
Question 2
Trade math · JP-F02
A slope of 1/4 inch per foot is closest to what percent grade?
- A. 0.25%
- B. 1.04%
- C. 2.08%
- D. 4.17%
Show answer and explanation — Question 2
Answer: C. 2.08%
Percent grade = rise ÷ run × 100. Put both in inches: 0.25 in ÷ 12 in = 0.0208, or about 2.08%. 1.04% is 1/8 in/ft and 4.17% is 1/2 in/ft. 0.25% comes from forgetting to divide by 12.
Source: Arithmetic shown above.
Question 3
Trade math · JP-F03
A round tank is 2 feet in diameter and 3 feet tall. Using 1 cubic foot = 7.481 gallons, about how many gallons does it hold when full?
- A. 282 gallons
- B. 94.2 gallons
- C. 70.5 gallons
- D. 22.4 gallons
Show answer and explanation — Question 3
Answer: C. 70.5 gallons
Volume of a cylinder = π × radius² × height. Radius = 1 ft, so π × 1 × 3 = 9.42 cubic feet. 9.42 × 7.481 = 70.5 gallons. 282 gallons comes from squaring the diameter instead of the radius. 22.4 gallons skips π.
Source: NIST Handbook 44 (2026), Appendix C, Units of Capacity or Volume.
Question 4
Trade math · JP-F04
You need a 45-degree offset that moves a pipe over 12 inches. Measured center to center, how long is the diagonal (travel) piece?
- A. 12 inches
- B. 14.1 inches
- C. About 17 inches
- D. 24 inches
Show answer and explanation — Question 4
Answer: C. About 17 inches
For a 45° offset, travel = offset × 1.414 (the square root of 2). 12 × 1.414 = 16.97, or about 17 inches. 12 inches ignores the angle, and 24 inches doubles it. 14.1 slides the decimal point in 1.414 and adds it to 12.
Source: Arithmetic shown above.
Question 5
Jobsite safety · JP-F05
You are working in a trench 5 feet deep. Under OSHA's construction rules, how far can you be from a ladder, stairway, ramp, or other safe way out?
- A. No more than 25 feet of lateral travel
- B. No more than 10 feet of lateral travel
- C. No more than 50 feet of lateral travel
- D. No exit is required until the trench is 20 feet deep
Show answer and explanation — Question 5
Answer: A. No more than 25 feet of lateral travel
OSHA requires a safe means of egress in trenches 4 feet or deeper, placed so workers travel no more than 25 feet sideways to reach it. Exit rules are federal safety law, separate from the plumbing code.
Source: OSHA 29 CFR 1926.651(c)(2).
Question 6
Jobsite safety · JP-F06
A trench is 4 feet deep. A competent person examined the soil and found no sign of a possible cave-in. The trench is not in stable rock. Under OSHA, is a protective system (sloping, shoring, or a shield) required?
- A. Yes, every trench needs one
- B. No, because only trenches over 20 feet need protection
- C. Yes, unless the trench is less than 2 feet wide
- D. No, because it is less than 5 feet deep and the competent person found no indication of a cave-in
Show answer and explanation — Question 6
Answer: D. No, because it is less than 5 feet deep and the competent person found no indication of a cave-in
OSHA requires cave-in protection unless the excavation is entirely in stable rock, or it is less than 5 feet deep and a competent person finds no indication of a potential cave-in. Both conditions are met here. Change either fact (5 feet or deeper, or signs of trouble) and protection is required.
Source: OSHA 29 CFR 1926.652(a)(1).
Part 2: 2021 IPC code questions
These questions follow the 2021 IPC. If your exam bulletin names the Uniform Plumbing Code (UPC), a different IPC edition, or state amendments, some answers will be different. Check every number against the book your exam assigns.
Question 7
Sanitary drainage · JP-IPC01
Under the 2021 IPC, what is the minimum slope for a 3-inch horizontal building drain?
- A. 1/16 inch per foot
- B. 1/8 inch per foot
- C. 1/4 inch per foot
- D. 1/2 inch per foot
Show answer and explanation — Question 7
Answer: B. 1/8 inch per foot
Table 704.1 sets slope by pipe size: 2-1/2 inches and smaller need 1/4 in/ft, 3 to 6 inches need 1/8 in/ft, and 8 inches and larger need 1/16 in/ft. A 3-inch drain falls in the 1/8 in/ft row. People pick 1/4 in/ft because it's the everyday slope on small branches. 1/2 in/ft isn't a minimum anywhere in the table.
Look it up: 2021 IPC §704.1 and Table 704.1. Source: 2021 IPC §704.1 (ICC); ICC Plumbing Code Essentials, slope table page.
Question 8
Sanitary drainage · JP-IPC02
A 2-inch horizontal fixture branch runs 36 feet at the minimum slope the 2021 IPC allows. What is the minimum total fall from end to end?
- A. 18 inches
- B. 9 inches
- C. 6 inches
- D. 4-1/2 inches
Show answer and explanation — Question 8
Answer: B. 9 inches
A 2-inch pipe is 2-1/2 inches or smaller, so the minimum is 1/4 in/ft. Fall = 36 × 1/4 = 9 inches. 4-1/2 inches is the answer at 1/8 in/ft, which only applies to 3-inch and larger pipe. 18 inches would be 1/2 in/ft.
Look it up: 2021 IPC Table 704.1. Source: 2021 IPC §704.1 (ICC); ICC Plumbing Code Essentials, slope table page.
Question 9
Sanitary drainage · JP-IPC03
A branch serves one bathroom group with a 1.6-gpf water closet, one domestic kitchen sink, and one residential automatic clothes washer. Using 2021 IPC Table 709.1, what is the total drainage fixture unit (DFU) load?
- A. 7 DFU
- B. 9 DFU
- C. 11 DFU
- D. 12 DFU
Show answer and explanation — Question 9
Answer: B. 9 DFU
Bathroom group with a 1.6-gpf water closet = 5, kitchen sink = 2, clothes washer = 2, so 9 DFU. When the fixtures make up a bathroom group, use the bathroom-group line instead of adding the water closet, lavatory and tub one by one. Counting them separately and then adding the group too is how people land on 11 or 12.
Look it up: 2021 IPC Table 709.1. Source: 2021 IPC §709.1 (ICC); ICC 2021 IPC Group A code-change document (reproduces Tables 308.5 and 709.1).
Question 10
Sanitary drainage · JP-IPC04
Under the 2021 IPC, what is the maximum distance between cleanouts in a horizontal drain line?
- A. 50 feet
- B. 75 feet
- C. 100 feet
- D. 150 feet
Show answer and explanation — Question 10
Answer: C. 100 feet
Cleanouts in horizontal drains can be no more than 100 feet apart, so a cleaning cable can reach any stoppage. Subsection numbers inside Section 708 have shifted between editions, so search for "100 feet" within 708 instead of memorizing a subsection number.
Look it up: 2021 IPC §708.1 (cleanouts required). Source: ICC IPC/IRC plumbing quick reference.
Question 11
Sanitary drainage · JP-IPC05
Under 2021 IPC Table 706.3, a sanitary tee may be used for which change of direction in drainage piping?
- A. Horizontal to vertical only
- B. Vertical to horizontal only
- C. Horizontal to horizontal only
- D. All three directions
Show answer and explanation — Question 11
Answer: A. Horizontal to vertical only
A sanitary tee works where waste drops into a vertical pipe. The table doesn't allow it for vertical-to-horizontal or horizontal-to-horizontal turns, where its short, sharp turn invites stoppages. Long-sweep bends, wyes and combination wye-and-eighth bends are allowed in all three directions.
Look it up: 2021 IPC §706.3 and Table 706.3. Source: ICC Plumbing Code Essentials, Table 706.3 pages.
Question 12
Testing · JP-IPC06
A DWV system is being tested with water under the 2021 IPC. What is the minimum test?
- A. A 5-foot head of water for 15 minutes
- B. A 10-foot head of water for 15 minutes
- C. A 10-foot head of water for 1 hour
- D. 5 psi for 15 minutes
Show answer and explanation — Question 12
Answer: B. A 10-foot head of water for 15 minutes
The water test fills the system to give at least a 10-foot head and holds it for 15 minutes with no leaks. 5 psi for 15 minutes is the air test. That's a common trap, because both tests last 15 minutes.
Look it up: 2021 IPC §312.2. Source: ICC IPC/IRC plumbing quick reference.
Question 13
Testing · JP-IPC07
For nonplastic DWV piping, what is the air test required by the 2021 IPC?
- A. 5 psi held for 1 hour
- B. 50 psi held for 15 minutes
- C. 10 psi held for 15 minutes
- D. 5 psi held for 15 minutes
Show answer and explanation — Question 13
Answer: D. 5 psi held for 15 minutes
For nonplastic DWV piping, the air test is 5 psi for at least 15 minutes. Plastic piping must not be tested using air. A 50-psi air test belongs to the water-supply-system test for nonplastic piping, not the drainage-and-vent air test.
Look it up: 2021 IPC §312.3. Source: 2021 IPC Chapter 3 (ICC).
Question 14
Traps · JP-IPC08
Under the 2021 IPC, what liquid seal must a standard fixture trap have?
- A. At least 1 inch, no more than 3 inches
- B. At least 2 inches, no more than 4 inches
- C. At least 2 inches, no more than 6 inches
- D. At least 4 inches, no maximum
Show answer and explanation — Question 14
Answer: B. At least 2 inches, no more than 4 inches
Every fixture trap needs a seal of 2 to 4 inches. The seal is the water barrier that keeps sewer gas out of the building, and the code sets both a minimum and a maximum depth. Deeper seals are allowed only for special designs relating to accessible fixtures.
Look it up: 2021 IPC §1002.4. Source: ICC Building Safety Journal: plumbing trap requirements under the IPC; ICC IPC/IRC plumbing quick reference.
Question 15
Traps · JP-IPC09
Under the 2021 IPC, what is the maximum vertical distance from a fixture outlet down to its trap weir?
- A. 18 inches
- B. 24 inches
- C. 30 inches
- D. 42 inches
Show answer and explanation — Question 15
Answer: B. 24 inches
24 inches vertical. The companion limit is 30 inches horizontal, from the fixture outlet centerline to the trap inlet centerline, which is why 30 is a tempting wrong answer. 42 inches is the top of the clothes washer standpipe range.
Look it up: 2021 IPC §1002.1. Source: ICC Building Safety Journal: plumbing trap requirements under the IPC; ICC IPC/IRC plumbing quick reference.
Question 16
Traps · JP-IPC10
Which of these traps is prohibited by the 2021 IPC?
- A. An S trap
- B. A P-trap with a 2-inch seal
- C. A trap built into a water closet
- D. A floor drain trap protected by a barrier-type device
Show answer and explanation — Question 16
Answer: A. An S trap
S traps are on the prohibited list, along with bell traps, drum traps, crown-vented traps, traps with moving parts, and traps that rely on interior partitions (unless made of approved corrosion-resistant material). The other three choices are ordinary, allowed installations.
Look it up: 2021 IPC §1002.3. Source: ICC Building Safety Journal: plumbing trap requirements under the IPC.
Question 17
Traps · JP-IPC11
An emergency floor drain in a mechanical room rarely gets water, so its trap seal could evaporate. Which of these is an approved way to protect the seal under the 2021 IPC?
- A. A check valve on the trap outlet
- B. A cleanout plug on the trap inlet
- C. A second trap installed in series
- D. A barrier-type trap seal protection device that conforms to ASSE 1072
Show answer and explanation — Question 17
Answer: D. A barrier-type trap seal protection device that conforms to ASSE 1072
The approved methods are a water-supplied trap seal primer valve (ASSE 1018), a waste-water-supplied trap primer device (ASSE 1044), or a barrier-type device (ASSE 1072). A second trap in series is double trapping, which the code prohibits. A check valve or plug does nothing to keep water in the seal.
Look it up: 2021 IPC §1002.4 (trap seal protection subsections). Source: ICC Building Safety Journal: plumbing trap requirements under the IPC.
Question 18
Traps · JP-IPC12
Under the 2021 IPC, a two-compartment sink may be served by a single trap when:
- A. One compartment is not more than 6 inches deeper than the other and the waste outlets are not more than 30 inches apart
- B. The compartments are the same depth and the outlets are no more than 18 inches apart
- C. The trap is at least 3 inches in diameter
- D. Each compartment has its own vent
Show answer and explanation — Question 18
Answer: A. One compartment is not more than 6 inches deeper than the other and the waste outlets are not more than 30 inches apart
The exception in §1002.1 allows one trap when the compartments differ in depth by no more than 6 inches and the waste outlets are no more than 30 inches apart. The other choices aren't conditions the code uses.
Look it up: 2021 IPC §1002.1 (exceptions). Source: ICC Building Safety Journal: plumbing trap requirements under the IPC.
Question 19
Traps · JP-IPC13
Under the 2021 IPC, how far must a clothes washer standpipe extend above its trap weir?
- A. 6 to 18 inches
- B. 12 to 30 inches
- C. 18 to 42 inches
- D. 24 to 48 inches
Show answer and explanation — Question 19
Answer: C. 18 to 42 inches
At least 18 inches and no more than 42 inches above the trap weir. A quick way to remember it: 18 low, 42 high. "6 to 18" looks plausible because 18 shows up, but it's the minimum, not the maximum.
Look it up: 2021 IPC §802 (standpipes). Source: ICC IPC/IRC plumbing quick reference.
Question 20
Venting · JP-IPC14
Under the 2021 IPC, what is the maximum distance from a 1-1/2-inch fixture trap to its vent when the trap arm slopes 1/4 inch per foot?
- A. 3 feet 6 inches
- B. 5 feet
- C. 6 feet
- D. 8 feet
Show answer and explanation — Question 20
Answer: C. 6 feet
Table 909.1: 1-1/4 in = 5 ft, 1-1/2 in = 6 ft, 2 in = 8 ft, 3 in = 12 ft, 4 in = 16 ft. 3 feet 6 inches (42 inches) is the Uniform Plumbing Code (UPC) limit for a 1-1/2-inch trap arm, so plumbers trained on the UPC often pick it on an IPC exam. In the 2021 IPC this is Table 909.1. Table 906.1 is a different table, for stack vent and vent stack sizing.
Look it up: 2021 IPC Table 909.1. Source: ICC: Methods of Venting Plumbing Fixtures and Traps in the 2021 IPC (brochure).
Question 21
Venting · JP-IPC15
An individual vent serves a fixture drain that is 3 inches. The vent is shorter than 40 feet. Under the 2021 IPC, what is its minimum size?
- A. 1-1/4 inches
- B. 1-1/2 inches
- C. 2 inches
- D. 3 inches
Show answer and explanation — Question 21
Answer: B. 1-1/2 inches
An individual vent must be at least one-half the diameter of the drain it serves, and never smaller than 1-1/4 inches. Half of 3 inches is 1-1/2 inches. 1-1/4 inches is the absolute floor, but it's less than half of this drain.
Look it up: 2021 IPC §906.2. Source: ICC: Methods of Venting Plumbing Fixtures and Traps in the 2021 IPC (brochure); ICC Building Safety Journal: venting methods in the 2021 IPC.
Question 22
Venting · JP-IPC16
A vent pipe has a developed length of 50 feet. What does the 2021 IPC require?
- A. Nothing extra, because length doesn't affect vent size
- B. Increase it one size only for the part beyond 40 feet
- C. Install an air admittance valve at the 40-foot mark
- D. Increase it one nominal pipe size for its entire developed length
Show answer and explanation — Question 22
Answer: D. Increase it one nominal pipe size for its entire developed length
Vents longer than 40 feet in developed length must be one nominal pipe size larger for their entire length, not just the extra footage. A longer run means more friction for the air moving through it.
Look it up: 2021 IPC §906.2. Source: ICC: Methods of Venting Plumbing Fixtures and Traps in the 2021 IPC (brochure).
Question 23
Venting · JP-IPC17
Under the 2021 IPC, what is the maximum number of fixtures on a horizontal branch that can be circuit vented?
- A. 4
- B. 6
- C. 8
- D. 10
Show answer and explanation — Question 23
Answer: C. 8
Circuit venting can serve up to 8 fixtures on a horizontal branch. The circuit vent connects between the two most upstream fixture drains.
Look it up: 2021 IPC §914. Source: ICC: Methods of Venting Plumbing Fixtures and Traps in the 2021 IPC (brochure).
Question 24
Venting · JP-IPC18
Under the 2021 IPC, which fixture may NOT connect to a combination waste and vent system?
- A. Floor drain
- B. Lavatory
- C. Drinking fountain
- D. Water closet
Show answer and explanation — Question 24
Answer: D. Water closet
A combination waste and vent system is an oversized horizontal drain that carries both waste and air. It's limited to floor drains, sinks, lavatories and drinking fountains. Water closets aren't on the list.
Look it up: 2021 IPC §915. Source: ICC: Methods of Venting Plumbing Fixtures and Traps in the 2021 IPC (brochure).
Question 25
Venting · JP-IPC19
A vent will terminate 6 feet horizontally from an openable window. Under the 2021 IPC, what is required?
- A. The vent must terminate at least 3 feet above the top of the window
- B. Nothing, because 6 feet is enough separation
- C. The vent must terminate at least 1 foot below the window
- D. The vent must be fitted with an air admittance valve
Show answer and explanation — Question 25
Answer: A. The vent must terminate at least 3 feet above the top of the window
A vent terminal within 10 feet horizontally of a door, openable window or air intake must rise at least 3 feet above the top of that opening, so sewer gas doesn't drift inside. A vent can never terminate directly beneath one.
Look it up: 2021 IPC §903 (location of vent terminal). Source: ICC sample: 2021 Michigan Plumbing Code (IPC-based), vent terminal text.
Source-link update — October 2, 2026: The ICC sample-PDF link above returned 404. Consult the precise code section instead: 2021 IPC §903.5, Location of vent terminal. ICC's code reader blocked automated access checks; normal browser access was not independently verified.
Question 26
Venting · JP-IPC20
Under the 2021 IPC, an air admittance valve must be located at least how far above the horizontal branch drain or fixture drain it vents?
- A. 2 inches
- B. 4 inches
- C. 6 inches
- D. 12 inches
Show answer and explanation — Question 26
Answer: B. 4 inches
At least 4 inches above the drain being vented, so drainage water can't reach the valve. 6 inches is the clearance an air admittance valve needs above insulation material, which makes it the usual mix-up.
Look it up: 2021 IPC §918 (air admittance valves). Source: ICC: Methods of Venting Plumbing Fixtures and Traps in the 2021 IPC (brochure).
Question 27
Venting · JP-IPC21
Two individual vents will be joined into a single vent. Under the 2021 IPC, where may they connect?
- A. Anywhere below the fixtures, as long as the pipe slopes back to the drain
- B. At least 42 inches above the floor
- C. Only above the roof
- D. At least 6 inches above the flood level rim of the highest fixture served
Show answer and explanation — Question 27
Answer: D. At least 6 inches above the flood level rim of the highest fixture served
Individual vents may connect and continue as one vent, but the connection has to be at least 6 inches above the flood level rim of the highest fixture served. That keeps waste from backing up into the vent if a drain stops up.
Look it up: 2021 IPC §905.5. Source: ICC Building Safety Journal: venting methods in the 2021 IPC.
Question 28
Water supply · JP-IPC22
Under the 2021 IPC, a pressure-reducing valve is required when the static water pressure is more than:
- A. 60 psi
- B. 70 psi
- C. 80 psi
- D. 100 psi
Show answer and explanation — Question 28
Answer: C. 80 psi
When static pressure is over 80 psi, install an approved pressure-reducing valve with a strainer to protect fixtures, valves and water heaters. The valve standard, ASSE 1003, is referenced at §604.8.
Look it up: 2021 IPC §604.8. Source: ICC sample: 2021 IPC Chapter 15 referenced standards.
Source-link update — October 2, 2026: The ICC sample-PDF link above returned 404. Consult the precise code section instead: 2021 IPC §604.8, Pressure-reducing valves. ICC's code reader blocked automated access checks; normal browser access was not independently verified.
Question 29
Backflow · JP-IPC23
A potable water outlet has an effective opening of 3/4 inch and discharges away from a wall. Under 2021 IPC Table 608.16.1, what is the minimum air gap above the flood level rim?
- A. 3/4 inch
- B. 1 inch
- C. 1-1/2 inches
- D. 2 inches
Show answer and explanation — Question 29
Answer: C. 1-1/2 inches
For a sink or similar outlet with an effective opening not greater than 3/4 inch, Table 608.16.1 requires a 1-1/2-inch air gap when the outlet is away from a wall. The same table requires a larger 2-1/2-inch gap when it is close to a wall, which is why the wall condition belongs in the question stem.
Look it up: 2021 IPC §608.16.1 and Table 608.16.1. Source: 2021 IPC Chapter 6 (ICC).
Question 30
Backflow · JP-IPC24
A lawn irrigation system has zone valves downstream of its backflow preventer, so the device will be under continuous pressure. Which device does the 2021 IPC NOT allow in that position?
- A. Reduced pressure principle assembly
- B. Pressure vacuum breaker assembly
- C. Atmospheric vacuum breaker
- D. None of these can be under continuous pressure
Show answer and explanation — Question 30
Answer: C. Atmospheric vacuum breaker
An atmospheric vacuum breaker protects against backsiphonage only. It can't be under continuous pressure, so it can't have a shutoff valve downstream. Pressure vacuum breakers and RP assemblies are designed for continuous pressure, which also rules out the last choice.
Look it up: 2021 IPC Table 608.1 and §608 vacuum breaker provisions. Source: ICC CodeNotes: Backflow Prevention (2021 IPC).
Question 31
Backflow · JP-IPC25
A boiler makeup water connection supplies chemically treated water (a high hazard), and backpressure is possible. Which device fits under the 2021 IPC?
- A. Reduced pressure principle backflow prevention assembly (ASSE 1013)
- B. Atmospheric vacuum breaker
- C. Hose connection vacuum breaker
- D. Dual check valve
Show answer and explanation — Question 31
Answer: A. Reduced pressure principle backflow prevention assembly (ASSE 1013)
An RP assembly is approved for high hazard under both backpressure and backsiphonage. Vacuum breakers handle backsiphonage only, and a dual check isn't rated for high hazard.
Look it up: 2021 IPC Table 608.1. Source: ICC CodeNotes: Backflow Prevention (2021 IPC).
Question 32
Fixtures · JP-IPC26
Which shower does NOT meet the 2021 IPC minimum size?
- A. 30 in × 30 in
- B. 32 in × 32 in
- C. 28 in × 36 in
- D. 30 in × 36 in
Show answer and explanation — Question 32
Answer: C. 28 in × 36 in
A shower needs at least 900 square inches of interior area and at least 30 inches in its smallest dimension. 28 × 36 = 1,008 square inches, so it passes on area but fails because one side is only 28 inches. 30 × 30 = 900 square inches, which is exactly enough.
Look it up: 2021 IPC §421.4 (it was §417.4 in older editions). Source: 2021 International Plumbing Code (ICC, free read-only).
Question 33
Fixtures · JP-IPC27
A water closet will be installed beside a vanity. Under the 2021 IPC, what is the minimum distance from the water closet's centerline to the vanity?
- A. 12 inches
- B. 15 inches
- C. 18 inches
- D. 21 inches
Show answer and explanation — Question 33
Answer: B. 15 inches
15 inches from the centerline to any side wall, partition, vanity or other obstruction. Two other numbers from the same section: 30 inches center to center between water closets, and 21 inches of clear space in front. People often mix up the 21-inch front clearance with this one.
Look it up: 2021 IPC §405.3.1. Source: ICC Significant Changes: §405.3.1 water closet clearances; ICC IPC/IRC plumbing quick reference.
Question 34
Fixtures · JP-IPC28
Under the 2021 IPC, the hot water supplied to a bathtub or whirlpool tub filler must be limited to what maximum temperature?
- A. 140°F
- B. 120°F
- C. 115°F
- D. 110°F
Show answer and explanation — Question 34
Answer: B. 120°F
120°F maximum, limited by a device that conforms to ASSE 1070 (or CSA B125.3). Showers have their own 120°F limit, set by the limit stop on an ASSE 1016 / ASME A112.18.1 shower valve.
Look it up: 2021 IPC §412.5 (it was §424.5 in older editions). Source: ICC sample: 2021 IPC Chapter 15 referenced standards.
Source-link update — October 2, 2026: The ICC sample-PDF link above returned 404. Consult the precise code section instead: 2021 IPC §412.5, Bathtub and whirlpool bathtub water temperature limitation. ICC's code reader blocked automated access checks; normal browser access was not independently verified.
Question 35
Water heaters · JP-IPC29
Which detail makes a water heater's relief valve discharge pipe NOT comply with the 2021 IPC?
- A. It drains by gravity to the floor
- B. It is the same size as the relief valve outlet
- C. It ends 4 inches above the floor
- D. Its end is threaded
Show answer and explanation — Question 35
Answer: D. Its end is threaded
The discharge pipe can't have a threaded end, so no one can cap it. It also has to be at least the size of the valve outlet, drain by gravity without sags, have no valves or tees, and end no more than 6 inches above the floor. The other three choices all comply.
Look it up: 2021 IPC §504.6. Source: ICC CodeNotes: Water Heater Safety.
Question 36
Supports · JP-IPC30
Under 2021 IPC Table 308.5, what is the maximum horizontal support spacing for PVC pipe?
- A. 12 feet
- B. 10 feet
- C. 6 feet
- D. 4 feet
Show answer and explanation — Question 36
Answer: D. 4 feet
PVC needs horizontal support every 4 feet. 6 feet is the horizontal spacing for copper tubing 1-1/4 inches and smaller. 10 feet is PVC's vertical spacing.
Look it up: 2021 IPC §308.5 and Table 308.5. Source: ICC 2021 IPC Group A code-change document (reproduces Tables 308.5 and 709.1).
How to read your score
Count your correct answers out of 36. If you also want a code-only number, count questions 7–36 separately, out of 30.
Use the result as practice feedback, not as a pass/fail cutoff. Review every miss and every answer you guessed, then find the listed section in the code book assigned to your exam. A topic represented by only a few questions here can show you what to review, but it cannot measure your full readiness for a licensing exam.
Your score on this set is not an official score, a scaled score, or a prediction that you will pass.
How journeyman plumber exams differ by state
There's no single national journeyman plumber licensing exam. State and local licensing authorities—and, in some settings, certifiers—set the code edition, amendments, exam format and reference rules that apply to their candidates. Here's how six state systems currently handle journeyman-level testing, taken from their official exam documents:
| State | Code tested | Questions and time | To pass | Code books | Official source |
|---|---|---|---|---|---|
| Colorado | 2021 IPC and 2021 IRC | 100 scored questions, 240 minutes, plus up to 10 unscored | 70% (70 correct) | Provided at the test center. No writing, highlighting or tabs. | PSI bulletin, updated 9/3/2026 |
| Georgia | 2024 Georgia Plumbing Code (IPC-based) and Georgia gas code | 100 scored questions plus 20 pretest, 5 hours in two parts | Scaled score of 70 | Open book | PSI bulletin, rev. 11/1/2024 |
| Montana | 2021 UPC | 100 questions in 3 hours, plus a 2.5-hour practical exam | 70% | Open book; bring your own 2021 UPC with factory tabs | Montana plumbing licensing information, rev. 1/9/2023 |
| Texas | Your choice: 2018 IPC with 2018 International Fuel Gas Code, or 2018 UPC | Written: 100 questions, 120 minutes. Practical: 6 items, 240 minutes. | 70% | Not stated in the handbook | Pearson VUE TSBPE Candidate Handbook, Aug. 2025 |
| Virginia | 2021 IPC plus Virginia regulations | 80 questions, 210 minutes | 60 correct out of 80 | Open book; permanent tabs only | PSI Virginia Tradesmen bulletin, dated 7/23/2026 |
| Washington | UPC with Washington amendments (L&I's exam page names the 2015 UPC) | Three parts, 90 minutes each: 100 code and trade questions, 25 waste-and-vent drawing questions, 25 water-sizing drawing questions | 70% on each part | Closed book; some sizing tables are provided | PSI bulletin, rev. 7/30/2026 and L&I plumber exam page |
Last verified: October 2, 2026. Bulletins get replaced without much notice, so download the current one from your board or test vendor before you study.
Texas also requires a hands-on practical. Its Journeyman Plumber Examination Review Course describes cutting and assembling pipe and designing a two-story drainage and vent system on a scaled model.
Is the journeyman plumbing exam open book?
It depends on your state:
- Virginia, Georgia and Montana: you bring your own code book, and tabs are allowed under each state's rules.
- Colorado: gives you the code books at the test center, and you can't mark them.
- Washington: closed book, with some sizing tables provided.
If your exam is open book, practice finding sections quickly. That's why every code answer above names the section to look up. If your exam is closed book, first verify the edition and amendments your bulletin assigns, then practice recalling the rules from that assigned material.
IPC or UPC: does it change the answers?
Sometimes, yes. The International Code Council, which publishes the IPC, says 37 states plus Washington, D.C., Puerto Rico and Guam adopt the IPC at the state or local level. The UPC, published by IAPMO, is the state-adopted code in places such as California, Washington, Idaho and Minnesota, and Montana tests on it too.
Here's one question where the code really does change the answer:
| Maximum trap arm length, 1-1/2-inch trap | Answer |
|---|---|
| 2021 IPC, Table 909.1 | 6 feet |
| 2018 UPC, Table 1002.2 | 42 inches (3 feet 6 inches) |
Some rules also match across the cited editions. For example, the 2021 IPC and the cited 2018 UPC both use a 2-to-4-inch trap-seal range.
The UPC figure comes from the 2018 UPC Chapter 10 as published by the City of Lynnwood, Washington.
If your exam uses the UPC, Part 1 still applies to you. Treat Part 2 as practice with the concepts, and confirm every number in your UPC edition.
Which topics carry the most weight
Each state publishes its own content outline, so start with yours. As an example, here is how Colorado's journeyworker bulletin splits its 100 scored questions:
| Colorado topic | Questions |
|---|---|
| Sanitary drainage | 20 |
| Vents | 18 |
| Water supply | 15 |
| Storm drainage | 10 |
| Fixtures and equipment | 8 |
| Water heaters | 7 |
| General regulations | 5 |
| Traps, interceptors and separators | 5 |
| Indirect and special waste | 5 |
| Isometric analysis | 5 |
| Residential fire sprinklers | 2 |
Drainage and venting lead in Colorado's outline, and they make up the largest share of the code questions in this test too. Your state's split will be different.
What this test doesn't cover
A multiple-choice code quiz can't practice everything. Plan for these separately:
- Isometric and DWV drawings. Colorado scores isometric analysis questions, and Washington has two separate drawing parts.
- Fuel gas pipe sizing. For example, Texas candidates who choose the IPC study the International Fuel Gas Code.
- State law and rules questions. For example, Virginia tests its own regulations.
- Hands-on practical exams. Texas and Montana both have one.
- Storm drainage sizing and water pipe sizing tables.
Your state bulletin's outline tells you how much of each to expect.
How to use this practice test
- Take it once without a code book. Note every question you weren't sure about, even the ones you got right.
- Go back with the book open. For each miss or guess, find the section listed under "Look it up" and read the whole section, not just the one number. Many questions here pair a rule with its nearest look-alike, like the 24-inch trap drop and the 30-inch horizontal distance.
- Time your lookups if your exam is open book. Finding the right table quickly is part of the test.
- Retake it in a day or two. These questions won't appear on your real exam, so the goal is knowing the rules, not remembering these answers.
Sources and independence
These questions were written by the Castleport Test Prep Editorial Team. We checked them against documents published by the International Code Council (ICC), OSHA regulations, NIST conversion tables and the official state bulletins linked above.
- The 2021 IPC itself: free read-only access from ICC.
- Supporting ICC publications:
- Safety and conversions:
Last verified: October 2, 2026 (state exam details, code values and source links).
Castleport Test Prep is an independent exam prep publisher. We are not affiliated with, endorsed by, or approved by the International Code Council, IAPMO, OSHA, any state plumbing board, PSI, Pearson VUE or any other test vendor. Exam, code and credential names identify the subjects being studied, and trademarks belong to their respective owners. These are original practice questions, not questions from any real exam, and no practice score guarantees a passing result or a license.