Free practice test — 12 questions with full explanations
Original CraftPATH practice questions. These are not real exam questions. Every answer includes the reasoning, why each wrong option fails, the code area it comes from, and the misconception it targets.
Question 1. A 3-inch horizontal building drain runs 40 feet. At the code minimum slope for 3-inch pipe, how much total fall does it need?
Drainage, Waste and Vent · Medium · Objective: Size a horizontal drain slope.
- A. 5 inches
- B. 10 inches (correct)
- C. 20 inches
- D. 40 inches
Correct answer: B. 10 inches
Why this is right: Drains 3 inches and smaller are sloped at a minimum of 1/4 inch per foot. Over 40 feet that is 40 x 0.25 = 10 inches of fall.
Why the other options are wrong:
- A. 5 inches — 1/8 inch per foot is the minimum for pipe 4 inches and larger, not 3-inch pipe.
- C. 20 inches — 1/2 inch per foot is roughly double the minimum and would be an unusual design slope, not the code minimum.
- D. 40 inches — One inch per foot is far steeper than any code minimum and can let liquid outrun solids.
Where this shows up on the job: Under-sloped 3-inch branches in remodels are one of the most common rough-in rejections, and they usually surface only after the slab is poured.
Code reference: Uniform Plumbing Code, drainage slope table (Texas adopts the UPC or IPC depending on the local jurisdiction)
Common misconception: Assuming 1/8 inch per foot applies to every drain size.
Question 2. What is the minimum and maximum liquid seal depth for a plumbing fixture trap under the model codes Texas jurisdictions adopt?
Drainage, Waste and Vent · Easy · Objective: Identify trap seal requirements.
- A. 1 inch minimum, 2 inches maximum
- B. 2 inches minimum, 4 inches maximum (correct)
- C. 3 inches minimum, 6 inches maximum
- D. No minimum, 4 inches maximum
Correct answer: B. 2 inches minimum, 4 inches maximum
Why this is right: A fixture trap must hold a liquid seal of at least 2 inches and not more than 4 inches, except where a deeper seal is required for evaporation-prone conditions.
Why the other options are wrong:
- A. 1 inch minimum, 2 inches maximum — A 1-inch seal blows out too easily under pressure fluctuations and is below code.
- C. 3 inches minimum, 6 inches maximum — A 3-to-6-inch seal exceeds the maximum and increases the chance of self-siphonage and fouling.
- D. No minimum, 4 inches maximum — There is always a minimum; without one the trap cannot reliably block sewer gas.
Where this shows up on the job: Deep-seal traps get installed on floor drains in mechanical rooms specifically because evaporation, not siphonage, is what breaks those seals.
Code reference: Uniform Plumbing Code, traps and interceptors chapter
Common misconception: Believing a deeper trap is always better; oversized seals collect solids and can foul.
Question 3. A hose bibb serving a landscape connection must be protected against backflow with which minimum device?
Water Supply and Distribution · Medium · Objective: Apply backflow protection.
- A. An air gap
- B. A hose-connection vacuum breaker (correct)
- C. A reduced-pressure principle assembly
- D. No protection is required on hose bibbs
Correct answer: B. A hose-connection vacuum breaker
Why this is right: A hose-connection (atmospheric) vacuum breaker on the outlet is the minimum required protection for a hose bibb, because a hose can be submerged in a contaminated source.
Why the other options are wrong:
- A. An air gap — An air gap is the strongest protection but is not practical or required at a hose outlet.
- C. A reduced-pressure principle assembly — An RP assembly is required for high-hazard cross connections such as boiler feed or irrigation with chemical injection, not a plain hose bibb.
- D. No protection is required on hose bibbs — Hose bibbs are a classic cross-connection hazard and always require protection.
Where this shows up on the job: Inspectors routinely fail exterior hose bibbs on new residential work because the vacuum breaker was left off or a cap was installed backwards.
Code reference: Uniform Plumbing Code, cross-connection control provisions
Common misconception: Treating a check valve as equivalent to a vacuum breaker.
Question 4. A quick-closing solenoid valve on a commercial dishwasher causes banging in the wall. The correct code-compliant fix is to:
Water Supply and Distribution · Hard · Objective: Diagnose water hammer.
- A. Increase the pipe size to slow velocity
- B. Install a listed water hammer arrestor near the quick-closing valve (correct)
- C. Install an additional shutoff valve upstream
- D. Lower the building water pressure to 20 psi
Correct answer: B. Install a listed water hammer arrestor near the quick-closing valve
Why this is right: Codes require water hammer arrestors where quick-closing valves are installed, and they must be located near the valve causing the surge.
Why the other options are wrong:
- A. Increase the pipe size to slow velocity — Upsizing lowers velocity somewhat, but it does not absorb the pressure spike from an instantaneous valve closure.
- C. Install an additional shutoff valve upstream — Another shutoff adds no surge absorption.
- D. Lower the building water pressure to 20 psi — Dropping system pressure to 20 psi would starve fixtures and is below typical minimum design pressure.
Where this shows up on the job: Air chambers that were once used for this waterlog within months; a listed arrestor with a sealed piston or bellows is what actually holds up.
Code reference: Uniform Plumbing Code, water hammer provisions; ASSE 1010 arrestor standard
Common misconception: Assuming a capped stub of pipe is a permanent hammer arrestor.
Question 5. When sizing natural gas piping using the longest-length method, the length used for every section of the system is:
Gas Piping · Medium · Objective: Size a gas branch.
- A. The length of that individual section
- B. The distance from the meter to the most remote outlet (correct)
- C. The total developed length of all piping added together
- D. The shortest run in the system
Correct answer: B. The distance from the meter to the most remote outlet
Why this is right: With the longest-length method, all sections are sized from the column corresponding to the distance from the point of delivery to the most remote outlet.
Why the other options are wrong:
- A. The length of that individual section — That is the branch-length method, an alternative that is used only when the code and the sizing tables allow it.
- C. The total developed length of all piping added together — Summing every section grossly overstates the length and oversizes the system.
- D. The shortest run in the system — Using the shortest run understates pressure drop and undersizes pipe.
Where this shows up on the job: Undersized gas piping shows up as a furnace that cannot hold manifold pressure when the water heater and range fire at the same time.
Code reference: National Fuel Gas Code (NFPA 54) / Uniform Plumbing Code fuel gas provisions
Common misconception: Sizing each section by its own length when the longest-length method is being used.
Question 6. Before a fuel gas piping system is placed in service it must be:
Gas Piping · Medium · Objective: Apply gas pressure testing.
- A. Filled with water and hydrostatically tested
- B. Pressure tested with air, nitrogen, or another inert gas and held for the required duration (correct)
- C. Tested with the appliance gas valves open to confirm flow
- D. Tested only if the inspector requests it
Correct answer: B. Pressure tested with air, nitrogen, or another inert gas and held for the required duration
Why this is right: Fuel gas piping is proof-tested with air or an inert gas at the required pressure and held for the required time with the appliances and their shutoff valves isolated.
Why the other options are wrong:
- A. Filled with water and hydrostatically tested — Water is never used to test gas piping; residual moisture causes corrosion and control failure.
- C. Tested with the appliance gas valves open to confirm flow — Appliance controls are not rated for test pressure and must be isolated.
- D. Tested only if the inspector requests it — Testing is a code requirement, not an inspector option.
Where this shows up on the job: Isolating appliance regulators before pressurizing is the step most often skipped, and it destroys the regulator diaphragm.
Code reference: National Fuel Gas Code (NFPA 54), inspection and testing chapter
Common misconception: Leaving appliance shutoffs open during the pressure test.
Question 7. A wet vent is best described as:
Venting · Hard · Objective: Distinguish vent types.
- A. A vent that has been flooded by a drainage backup
- B. A vent that also carries drainage from other fixtures (correct)
- C. A vent installed below the flood level rim
- D. A vent terminating inside the building
Correct answer: B. A vent that also carries drainage from other fixtures
Why this is right: A wet vent is a portion of a drain pipe that serves as a vent for one or more fixtures while simultaneously carrying drainage from other fixtures, within the size and fixture-unit limits the code sets.
Why the other options are wrong:
- A. A vent that has been flooded by a drainage backup — Flooding is a failure condition, not a defined vent type.
- C. A vent installed below the flood level rim — A vent below the flood level rim would be an improperly installed vent, and is separately restricted.
- D. A vent terminating inside the building — Vent termination location is a separate requirement and does not define wet venting.
Where this shows up on the job: Wet venting a bath group is a legitimate money saver on residential rough-in, but only when the fixture-unit loading and pipe sizes stay inside the table.
Code reference: Uniform Plumbing Code, venting chapter (wet venting provisions)
Common misconception: Wet venting fixtures that exceed the allowed fixture-unit load for the wet-vented section.
Question 8. A vent terminal that is within 10 feet horizontally of an operable window must terminate:
Venting · Medium · Objective: Apply vent termination rules.
- A. Level with the top of the window
- B. At least 3 feet above the top of the opening (correct)
- C. At least 6 inches above the roof
- D. Anywhere, provided it has a cap
Correct answer: B. At least 3 feet above the top of the opening
Why this is right: Where a vent terminal is within 10 feet horizontally of a door, window, or air intake, it must extend at least 3 feet above the top of that opening.
Why the other options are wrong:
- A. Level with the top of the window — Terminating level with the opening allows sewer gas to enter directly.
- C. At least 6 inches above the roof — Roof clearance is a separate minimum that does not satisfy the proximity-to-opening rule.
- D. Anywhere, provided it has a cap — A cap does not stop sewer gas migration into an opening.
Where this shows up on the job: Third-floor dormer windows are where this rule bites; the stack that cleared the main roof fine is now 4 feet from a bedroom window.
Code reference: Uniform Plumbing Code, vent terminal location provisions
Common misconception: Meeting only the roof-height minimum and ignoring nearby openings.
Question 9. A temperature and pressure relief valve discharge pipe must:
Water Heaters · Medium · Objective: Apply T&P relief discharge rules.
- A. Reduce one pipe size below the valve outlet for velocity
- B. Terminate with a threaded connection so a hose can be attached
- C. Run full size, discharge to an approved location, and terminate no more than 6 inches above the receptor (correct)
- D. Discharge into the nearest trap primer
Correct answer: C. Run full size, discharge to an approved location, and terminate no more than 6 inches above the receptor
Why this is right: The discharge line must be the full size of the valve outlet, run downward to an approved point of discharge, and terminate close enough to the floor or receptor to avoid scalding, with no valve or threaded end.
Why the other options are wrong:
- A. Reduce one pipe size below the valve outlet for velocity — Reducing the discharge pipe restricts relief flow and defeats the valve.
- B. Terminate with a threaded connection so a hose can be attached — A threaded termination invites a cap or hose being attached, which is prohibited.
- D. Discharge into the nearest trap primer — Discharging into a trap primer or any closed connection is not an approved termination.
Where this shows up on the job: A capped T and P discharge is one of the few plumbing defects that can turn a water heater into an explosive hazard, which is why inspectors always check it.
Code reference: Uniform Plumbing Code, water heater relief valve discharge provisions
Common misconception: Threading the end of the discharge line 'so it can be plumbed later.'
Question 10. In a closed water system with a backflow preventer on the service, a water heater requires:
Water Heaters · Easy · Objective: Understand thermal expansion.
- A. No additional device
- B. A thermal expansion tank or other approved means of controlling expansion (correct)
- C. A larger relief valve
- D. A recirculation pump
Correct answer: B. A thermal expansion tank or other approved means of controlling expansion
Why this is right: Once a check valve or backflow preventer closes the system, heated water cannot expand back into the main, so an expansion tank or other approved control is required.
Why the other options are wrong:
- A. No additional device — Without expansion control the relief valve becomes the pressure control device and will weep and eventually fail.
- C. A larger relief valve — Upsizing the relief valve does not address expansion and is not an approved substitute.
- D. A recirculation pump — A recirculation pump moves water but does not absorb thermal expansion.
Where this shows up on the job: Meters with built-in check valves quietly converted millions of open systems into closed ones, which is why weeping T and P valves became so common.
Code reference: Uniform Plumbing Code, thermal expansion control provisions
Common misconception: Blaming a weeping relief valve on a bad valve instead of an uncontrolled closed system.
Question 11. Plumbing licenses in Texas are issued and regulated by:
Texas Rules and Licensing · Medium · Objective: Identify board jurisdiction.
- A. Each individual city building department
- B. The Texas State Board of Plumbing Examiners (correct)
- C. The Texas Department of Licensing and Regulation only
- D. The National Plumbing Board
Correct answer: B. The Texas State Board of Plumbing Examiners
Why this is right: The Texas State Board of Plumbing Examiners licenses plumbers statewide under the Texas Plumbing License Law, while cities enforce their adopted plumbing code locally.
Why the other options are wrong:
- A. Each individual city building department — Cities enforce codes and issue permits but do not issue plumbing licenses.
- C. The Texas Department of Licensing and Regulation only — TDLR regulates electricians and air conditioning contractors; plumbing sits with TSBPE.
- D. The National Plumbing Board — There is no national plumbing licensing board.
Where this shows up on the job: Knowing which agency owns your license matters the day you need a duplicate, an endorsement, or a continuing-education record.
Code reference: Texas Occupations Code, Chapter 1301 (Plumbing License Law)
Common misconception: Assuming a city plumbing permit is the same thing as a state license.
Question 12. In Texas, a Medical Gas Piping Installation endorsement is:
Texas Rules and Licensing · Easy · Objective: Identify endorsements.
- A. Automatically included with a journeyman license
- B. A separate endorsement added to an existing plumbing license (correct)
- C. Issued only to master plumbers
- D. Not recognized in Texas
Correct answer: B. A separate endorsement added to an existing plumbing license
Why this is right: Texas recognizes separate endorsements, including Medical Gas Piping Installation and Multipurpose Residential Fire Protection Sprinkler Specialist, that are added to an existing license after additional training and examination.
Why the other options are wrong:
- A. Automatically included with a journeyman license — No endorsement is automatic with a journeyman license.
- C. Issued only to master plumbers — Endorsements are not restricted to master plumbers.
- D. Not recognized in Texas — Texas does recognize a medical gas endorsement.
Where this shows up on the job: Hospital and surgery-center work is effectively closed to you without the medical gas endorsement, and it is one of the better-paying niches in the trade.
Code reference: Texas Occupations Code, Chapter 1301; Texas State Board of Plumbing Examiners licensing pages
Common misconception: Thinking a journeyman license alone covers medical gas or fire sprinkler work.
How to study for the Texas journeyman plumber exam
Find out which code your jurisdiction adopted first
Texas does not have a single statewide plumbing code the way it has a single licensing board. Cities and counties adopt either the Uniform Plumbing Code or the International Plumbing Code, and the two differ on venting methods, sizing tables, and material approvals. Before you buy a study book, confirm which code edition your examination is written against and which one your local authority enforces, because studying the wrong table wastes weeks.
Learn the tables by navigation, not memory
The exam rewards people who can find a number quickly. Tab your code book for drain sizing, fixture unit loads, water supply sizing, gas pipe capacity, and vent sizing. Practice going from a question to the correct table in under fifteen seconds. Memorize only the handful of constants that recur everywhere: minimum slopes, trap seal depths, and the 10-foot / 3-foot vent terminal rule.
Drill drainage and venting until it is boring
Drainage and venting is the largest and most heavily weighted body of material on almost every journeyman plumbing exam. Work through fixture-unit loading, branch sizing, cleanout placement, and every venting method the code allows. Wet venting in particular is where candidates lose points, because the rules feel permissive until the fixture-unit limits are applied.
Treat gas piping as its own subject
Gas sizing questions are formulaic and highly scoreable if you know which method the question is using. Practice the longest-length method until you can pick the right column without hesitating, then work through branch-length problems, appliance connector rules, and the pressure test procedure including isolating regulators and appliance shutoffs.
Do not skip the law and rules section
Chapter 1301 of the Texas Occupations Code and the TSBPE rules produce straightforward recall questions that many candidates never study. Know the license classes, what an apprentice may and may not do, what a responsible master plumber is responsible for, how endorsements work, and the continuing-education requirement. These are the cheapest points on the exam.
Build a four-week plan and take timed sets
Week one: drainage and traps. Week two: venting. Week three: water supply, backflow, and water heaters. Week four: gas piping plus the law and rules, followed by mixed timed sets. Time yourself at roughly one question per minute so that open-book lookups do not eat the clock on exam day.
Frequently asked questions
How many questions are on the Texas journeyman plumber exam?
TSBPE publishes item counts and passing scores in its current candidate information bulletin through its examination vendor. We mark those figures pending rather than repeating numbers we cannot source, so confirm them when you register.
Is the Texas journeyman plumber exam open book?
Texas plumbing examinations are administered with the adopted code references specified in the candidate bulletin. Confirm exactly which references you may bring, and in what form, before test day.
Which plumbing code does Texas use?
There is no single statewide plumbing code. Local jurisdictions adopt either the Uniform Plumbing Code or the International Plumbing Code, so check the code and edition your jurisdiction and your examination use.
Who issues plumbing licenses in Texas?
The Texas State Board of Plumbing Examiners licenses plumbers statewide under the Plumbing License Law in Chapter 1301 of the Texas Occupations Code. Cities issue permits and enforce codes but do not issue licenses.
What endorsements can a Texas plumber add?
Texas recognizes the Medical Gas Piping Installation endorsement and the Multipurpose Residential Fire Protection Sprinkler Specialist endorsement, both added to an existing license after additional training and examination.
Are these real Texas exam questions?
No. Every question here is original CraftPATH material written to the same subject areas the exam covers. Reproducing live examination content would be unlawful and would not help you learn.
How long should I study?
Most candidates who already have field experience do well with four to six weeks of structured study focused on code navigation, drainage and venting, and gas sizing, plus the law and rules section.