UTAH PLUMBING CONTRACTOR EXAM – QUESTIONS AND ANSWERS | VERIFIED AND WELL
DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
- International Plumbing Code (IPC) Regulations - Utah State Construction and Fire Codes Act
- Business and Law for Contractors - Sanitary Drainage and Venting Systems - Water Supply
and Distribution - Fuel Gas Piping and Equipment - Storm Drainage and Special Piping - OSHA
Safety Standards and Excavation - Mathematics for Plumbing and Estimating - Backflow
Prevention and Cross-Connection Control
Introduction
The Utah Plumbing Contractor Exam is designed to evaluate the proficiency and competency
of individuals seeking licensure within the state. This comprehensive assessment ensures that
candidates possess the requisite knowledge of the International Plumbing Code as amended
by Utah state law, alongside essential business practices and safety protocols. The exam
consists of multiple-choice and scenario-based questions that require candidates to apply
technical theories to practical, real-world installation and repair situations. Emphasis is
placed on professional decision-making, regulatory compliance, and the protection of public
health through proper sanitary practices. Candidates must demonstrate a thorough
understanding of system design, legal obligations, and site safety to achieve a passing score.
SECTION ONE: QUESTIONS 1–100
1. What is the minimum required size for a building sewer in a residential application?
A. 2 inches B. 3 inches C. 4 inches D. 6 inches
Correct answer: B. 3 inches
Explanation: According to standard plumbing codes adopted in Utah, the building sewer
must be at least 3 inches in diameter to prevent blockages from solids.
2. When installing a trench for underground piping, what is the minimum distance
required for the placement of excavated soil from the edge of the trench for safety?
A. 1 foot B. 2 feet C. 3 feet D. 5 feet
Correct answer: B. 2 feet
Explanation: OSHA safety regulations require that the "spoil pile" be kept at least 2 feet
from the edge of the excavation to prevent cave-ins.
3. A plumbing contractor in Utah is required to keep records of all employees and
payroll for a minimum of how many years for state tax purposes?
A. 1 year B. 3 years C. 4 years D. 7 years
, Correct answer: B. 3 years
Explanation: State regulatory and tax guidelines generally require contractors to
maintain accurate payroll and employment records for at least three years.
4. Which of the following is considered a "cross-connection" in a plumbing system?
A. A connection between two different water heaters B. A connection between a potable
water supply and a non-potable source C. The union of a vent pipe and a soil stack D. The
installation of a cleanout in a horizontal drain line
Correct answer: B. A connection between a potable water supply and a non-potable
source
Explanation: A cross-connection is any actual or potential connection between a public
water system and any source of contamination or pollution.
5. What is the maximum distance a water heater can be located from the required
seismic bracing in Utah?
A. 6 inches B. 12 inches C. 18 inches D. 24 inches
Correct answer: B. 12 inches
Explanation: Utah state amendments emphasize seismic safety; water heaters must be
strapped in the upper and lower third of the tank, typically within 12 inches of the top and
bottom.
6. A horizontal drainage pipe has a diameter of 3 inches. What is the minimum slope
per foot required for this pipe?
A. 1/16 inch B. 1/8 inch C. 1/4 inch D. 1/2 inch
Correct answer: B. 1/8 inch
Explanation: For pipes 3 to 6 inches in diameter, the minimum required slope is 1/8 inch
per foot to maintain scouring velocity.
7. Which material is prohibited for use in a water distribution system located inside a
building?
A. Copper tubing (Type M) B. CPVC piping C. PEX piping D. Cellular core PVC
Correct answer: D. Cellular core PVC
Explanation: Cellular core PVC is intended for DWV (Drain, Waste, and Vent) systems and
lacks the pressure rating required for water distribution.
, 8. In a scenario where a contractor discovers a conflict between the approved plans and
the local code, which authority takes precedence?
A. The Architect B. The Homeowner C. The Local Plumbing Inspector D. The General
Contractor
Correct answer: C. The Local Plumbing Inspector
Explanation: The AHJ (Authority Having Jurisdiction) or local inspector enforces the code,
which always overrules non-compliant plans.
9. What is the purpose of an air gap in a plumbing system?
A. To allow for thermal expansion B. To prevent backflow through physical separation C. To
increase water pressure in the line D. To allow air to enter the vent system
Correct answer: B. To prevent backflow through physical separation
Explanation: An air gap is the most reliable method of backflow prevention because it
provides a literal physical break between the supply and the receiving vessel.
10. A worker falls on a job site and is injured because a guardrail was missing. Under
Utah law, who is primarily responsible for maintaining a safe work environment?
A. The injured worker B. The insurance company C. The employer/contractor D. The building
manufacturer
Correct answer: C. The employer/contractor
Explanation: Employers are legally obligated to provide a workplace free from recognized
hazards under OSHA and state safety laws.
11. What is the maximum temperature allowed for water discharged into a public sewer
system?
A. 110 degrees Fahrenheit B. 120 degrees Fahrenheit C. 140 degrees Fahrenheit D. 160
degrees Fahrenheit
Correct answer: C. 140 degrees Fahrenheit
Explanation: High-temperature discharge can damage PVC piping and disrupt biological
processes in sewage treatment, so it is capped at 140 degrees.
12. A "wet vent" is defined as:
A. A vent that remains filled with water at all times B. A pipe that serves both as a waste
pipe and a vent C. A vent that is installed outside the building envelope D. A vent connected
to a sump pump
, Correct answer: B. A pipe that serves both as a waste pipe and a vent
Explanation: Wet venting uses a single pipe to carry waste from one fixture while acting
as the air supply (vent) for another.
13. How many inches of water column (WC) is equal to 1 PSI?
A. 12.5 B. 27.7 C. 33.9 D. 14.7
Correct answer: B. 27.7
Explanation: 1 PSI is equivalent to approximately 27.7 inches of water column, a
standard measurement for gas pressure.
14. What is the minimum depth of a burial for a gas piping system installed outdoors
underground?
A. 6 inches B. 12 inches C. 18 inches D. 24 inches
Correct answer: B. 12 inches
Explanation: Fuel gas codes require a minimum cover of 12 inches for underground gas
piping to protect it from physical damage.
15. When testing a DWV system with air, what is the minimum pressure that must be
maintained for at least 15 minutes?
A. 3 PSI B. 5 PSI C. 10 PSI D. 15 PSI
Correct answer: B. 5 PSI
Explanation: The standard air test for a DWV system is 5 PSI, which is sufficient to
identify leaks without blowing out seals.
16. Which fixture requires a floor drain in the immediate vicinity in a commercial setting?
A. Lavatory B. Water closet C. Emergency eye wash station D. Indirect waste receptor
Correct answer: D. Indirect waste receptor
Explanation: Receptors receiving indirect waste (like those for food prep sinks) often
require floor drains to manage overflows and cleaning.
17. What is the maximum interval for supporting horizontal PVC drainage piping?
A. 2 feet B. 4 feet C. 6 feet D. 10 feet
Correct answer: B. 4 feet
Explanation: Horizontal PVC must be supported every 4 feet to prevent sagging, which
could disrupt the flow and slope.
DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
- International Plumbing Code (IPC) Regulations - Utah State Construction and Fire Codes Act
- Business and Law for Contractors - Sanitary Drainage and Venting Systems - Water Supply
and Distribution - Fuel Gas Piping and Equipment - Storm Drainage and Special Piping - OSHA
Safety Standards and Excavation - Mathematics for Plumbing and Estimating - Backflow
Prevention and Cross-Connection Control
Introduction
The Utah Plumbing Contractor Exam is designed to evaluate the proficiency and competency
of individuals seeking licensure within the state. This comprehensive assessment ensures that
candidates possess the requisite knowledge of the International Plumbing Code as amended
by Utah state law, alongside essential business practices and safety protocols. The exam
consists of multiple-choice and scenario-based questions that require candidates to apply
technical theories to practical, real-world installation and repair situations. Emphasis is
placed on professional decision-making, regulatory compliance, and the protection of public
health through proper sanitary practices. Candidates must demonstrate a thorough
understanding of system design, legal obligations, and site safety to achieve a passing score.
SECTION ONE: QUESTIONS 1–100
1. What is the minimum required size for a building sewer in a residential application?
A. 2 inches B. 3 inches C. 4 inches D. 6 inches
Correct answer: B. 3 inches
Explanation: According to standard plumbing codes adopted in Utah, the building sewer
must be at least 3 inches in diameter to prevent blockages from solids.
2. When installing a trench for underground piping, what is the minimum distance
required for the placement of excavated soil from the edge of the trench for safety?
A. 1 foot B. 2 feet C. 3 feet D. 5 feet
Correct answer: B. 2 feet
Explanation: OSHA safety regulations require that the "spoil pile" be kept at least 2 feet
from the edge of the excavation to prevent cave-ins.
3. A plumbing contractor in Utah is required to keep records of all employees and
payroll for a minimum of how many years for state tax purposes?
A. 1 year B. 3 years C. 4 years D. 7 years
, Correct answer: B. 3 years
Explanation: State regulatory and tax guidelines generally require contractors to
maintain accurate payroll and employment records for at least three years.
4. Which of the following is considered a "cross-connection" in a plumbing system?
A. A connection between two different water heaters B. A connection between a potable
water supply and a non-potable source C. The union of a vent pipe and a soil stack D. The
installation of a cleanout in a horizontal drain line
Correct answer: B. A connection between a potable water supply and a non-potable
source
Explanation: A cross-connection is any actual or potential connection between a public
water system and any source of contamination or pollution.
5. What is the maximum distance a water heater can be located from the required
seismic bracing in Utah?
A. 6 inches B. 12 inches C. 18 inches D. 24 inches
Correct answer: B. 12 inches
Explanation: Utah state amendments emphasize seismic safety; water heaters must be
strapped in the upper and lower third of the tank, typically within 12 inches of the top and
bottom.
6. A horizontal drainage pipe has a diameter of 3 inches. What is the minimum slope
per foot required for this pipe?
A. 1/16 inch B. 1/8 inch C. 1/4 inch D. 1/2 inch
Correct answer: B. 1/8 inch
Explanation: For pipes 3 to 6 inches in diameter, the minimum required slope is 1/8 inch
per foot to maintain scouring velocity.
7. Which material is prohibited for use in a water distribution system located inside a
building?
A. Copper tubing (Type M) B. CPVC piping C. PEX piping D. Cellular core PVC
Correct answer: D. Cellular core PVC
Explanation: Cellular core PVC is intended for DWV (Drain, Waste, and Vent) systems and
lacks the pressure rating required for water distribution.
, 8. In a scenario where a contractor discovers a conflict between the approved plans and
the local code, which authority takes precedence?
A. The Architect B. The Homeowner C. The Local Plumbing Inspector D. The General
Contractor
Correct answer: C. The Local Plumbing Inspector
Explanation: The AHJ (Authority Having Jurisdiction) or local inspector enforces the code,
which always overrules non-compliant plans.
9. What is the purpose of an air gap in a plumbing system?
A. To allow for thermal expansion B. To prevent backflow through physical separation C. To
increase water pressure in the line D. To allow air to enter the vent system
Correct answer: B. To prevent backflow through physical separation
Explanation: An air gap is the most reliable method of backflow prevention because it
provides a literal physical break between the supply and the receiving vessel.
10. A worker falls on a job site and is injured because a guardrail was missing. Under
Utah law, who is primarily responsible for maintaining a safe work environment?
A. The injured worker B. The insurance company C. The employer/contractor D. The building
manufacturer
Correct answer: C. The employer/contractor
Explanation: Employers are legally obligated to provide a workplace free from recognized
hazards under OSHA and state safety laws.
11. What is the maximum temperature allowed for water discharged into a public sewer
system?
A. 110 degrees Fahrenheit B. 120 degrees Fahrenheit C. 140 degrees Fahrenheit D. 160
degrees Fahrenheit
Correct answer: C. 140 degrees Fahrenheit
Explanation: High-temperature discharge can damage PVC piping and disrupt biological
processes in sewage treatment, so it is capped at 140 degrees.
12. A "wet vent" is defined as:
A. A vent that remains filled with water at all times B. A pipe that serves both as a waste
pipe and a vent C. A vent that is installed outside the building envelope D. A vent connected
to a sump pump
, Correct answer: B. A pipe that serves both as a waste pipe and a vent
Explanation: Wet venting uses a single pipe to carry waste from one fixture while acting
as the air supply (vent) for another.
13. How many inches of water column (WC) is equal to 1 PSI?
A. 12.5 B. 27.7 C. 33.9 D. 14.7
Correct answer: B. 27.7
Explanation: 1 PSI is equivalent to approximately 27.7 inches of water column, a
standard measurement for gas pressure.
14. What is the minimum depth of a burial for a gas piping system installed outdoors
underground?
A. 6 inches B. 12 inches C. 18 inches D. 24 inches
Correct answer: B. 12 inches
Explanation: Fuel gas codes require a minimum cover of 12 inches for underground gas
piping to protect it from physical damage.
15. When testing a DWV system with air, what is the minimum pressure that must be
maintained for at least 15 minutes?
A. 3 PSI B. 5 PSI C. 10 PSI D. 15 PSI
Correct answer: B. 5 PSI
Explanation: The standard air test for a DWV system is 5 PSI, which is sufficient to
identify leaks without blowing out seals.
16. Which fixture requires a floor drain in the immediate vicinity in a commercial setting?
A. Lavatory B. Water closet C. Emergency eye wash station D. Indirect waste receptor
Correct answer: D. Indirect waste receptor
Explanation: Receptors receiving indirect waste (like those for food prep sinks) often
require floor drains to manage overflows and cleaning.
17. What is the maximum interval for supporting horizontal PVC drainage piping?
A. 2 feet B. 4 feet C. 6 feet D. 10 feet
Correct answer: B. 4 feet
Explanation: Horizontal PVC must be supported every 4 feet to prevent sagging, which
could disrupt the flow and slope.
