LOUISIANA PLUMBING CONTRACTOR LICENSING EXAM – CLASSIFICATION 7] – QUESTIONS AND
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS |
LATEST EXAM UPDATE
CORE DOMAINS
Louisiana Plumbing Law and Licensing
Plumbing Code and Standards
Water Supply and Distribution Systems
Drainage, Waste, and Vent Systems
Backflow Prevention and Cross-Connection Control
Medical Gas and Specialty Piping Systems
Business and Project Management
Safety and Professional Responsibility
Ethics and Regulatory Compliance
INTRODUCTION
The Louisiana Plumbing Contractor Licensing Exam – Classification 7 is designed to assess the
knowledge, skills, and professional judgment required to perform plumbing contracting work in
compliance with Louisiana law and adopted plumbing codes. The examination evaluates candidates
across foundational theory, applied technical knowledge, regulatory compliance, ethical standards, and
real-world decision-making. Questions include both direct knowledge assessments and scenario-based
problems requiring analysis and practical application. The exam emphasizes critical thinking, problem-
solving, and the ability to interpret code requirements and apply them to workplace situations.
Candidates must demonstrate readiness to operate lawfully, safely, and ethically as plumbing contractors
in Louisiana.
SECTION ONE – QUESTIONS 1–100
Question 1
Which Louisiana state agency governs master and journeyman plumber licensing and plumbing code
enforcement?
,A. State Plumbing Board of Louisiana (SPBLA)
B. Louisiana Department of Wildlife and Fisheries
C. Federal Aviation Administration
D. Louisiana Department of Transportation and Development
🟢 Correct answer: A
🔴 Explanation: The State Plumbing Board of Louisiana (SPBLA) is the state agency responsible for
licensing master and journeyman plumbers and enforcing plumbing regulations throughout Louisiana.
Question 2
Under Louisiana law, what is the minimum slope requirement for a 3-inch horizontal drainage pipe?
A. 1/16 inch per foot
B. 1/8 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
🟢 Correct answer: C
🔴 Explanation: Per the adopted plumbing code, horizontal drainage pipes 3 inches or smaller require
a minimum slope of 1/4 inch per foot to ensure adequate flow and prevent clogs.
Question 3
What is the primary function of a plumbing vent system?
A. Increase water pressure to fixtures
B. Prevent trap siphonage and admit air into the drainage system
C. Filter waste materials from sewage
D. Heat water for distribution
🟢 Correct answer: B
🔴 Explanation: Vent systems equalize air pressure within the drainage system, protecting trap seals
from siphonage and allowing wastewater to flow freely.
,Question 4
Which Louisiana statute establishes the requirements for plumber licensing and regulation?
A. RS 37:1361 et seq.
B. RS 40:1730 et seq.
C. RS 9:4801 et seq.
D. RS 38:2211 et seq.
🟢 Correct answer: A
🔴 Explanation: Louisiana Revised Statute 37:1361 et seq. governs the licensing and regulation of
plumbers and plumbing contractors in the state.
Question 5
A plumbing contractor is installing a water supply system. Excessive incoming water pressure is
damaging fixtures. Which device should be installed?
A. Vacuum breaker
B. Water hammer arrestor
C. Pressure-reducing valve
D. Backwater valve
🟢 Correct answer: C
🔴 Explanation: A pressure-reducing valve regulates downstream water pressure when incoming
pressure exceeds acceptable operating limits, protecting fixtures and piping.
Question 6
Per the Louisiana Plumbing Code, what is the minimum trap seal depth for a plumbing fixture?
A. 1/2 inch
B. 1 inch
C. 2 inches
D. 4 inches
🟢 Correct answer: C
, 🔴 Explanation: A minimum trap seal depth of 2 inches is required to maintain an effective barrier
against sewer gases entering the building.
Question 7
Which license classification is required for a person who engages in the business of plumbing in
Louisiana?
A. Journeyman Plumber
B. Master Plumber
C. Apprentice Plumber
D. Residential Plumber Limited
🟢 Correct answer: B
🔴 Explanation: Only a licensed Master Plumber may engage in the business of plumbing, including
contracting for plumbing work and supervising journeymen.
Question 8
What is the maximum distance permitted between cleanouts in a horizontal drainage line?
A. 50 feet
B. 75 feet
C. 100 feet
D. 125 feet
🟢 Correct answer: C
🔴 Explanation: Cleanouts must be installed at intervals not exceeding 100 feet in horizontal drainage
lines to provide adequate access for cleaning and inspection.
Question 9
A journeyman plumber may perform plumbing work only under what condition?
A. When employed by a licensed master plumber
B. When working independently without supervision
C. When the work is limited to residential properties
ANSWERS | VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS |
LATEST EXAM UPDATE
CORE DOMAINS
Louisiana Plumbing Law and Licensing
Plumbing Code and Standards
Water Supply and Distribution Systems
Drainage, Waste, and Vent Systems
Backflow Prevention and Cross-Connection Control
Medical Gas and Specialty Piping Systems
Business and Project Management
Safety and Professional Responsibility
Ethics and Regulatory Compliance
INTRODUCTION
The Louisiana Plumbing Contractor Licensing Exam – Classification 7 is designed to assess the
knowledge, skills, and professional judgment required to perform plumbing contracting work in
compliance with Louisiana law and adopted plumbing codes. The examination evaluates candidates
across foundational theory, applied technical knowledge, regulatory compliance, ethical standards, and
real-world decision-making. Questions include both direct knowledge assessments and scenario-based
problems requiring analysis and practical application. The exam emphasizes critical thinking, problem-
solving, and the ability to interpret code requirements and apply them to workplace situations.
Candidates must demonstrate readiness to operate lawfully, safely, and ethically as plumbing contractors
in Louisiana.
SECTION ONE – QUESTIONS 1–100
Question 1
Which Louisiana state agency governs master and journeyman plumber licensing and plumbing code
enforcement?
,A. State Plumbing Board of Louisiana (SPBLA)
B. Louisiana Department of Wildlife and Fisheries
C. Federal Aviation Administration
D. Louisiana Department of Transportation and Development
🟢 Correct answer: A
🔴 Explanation: The State Plumbing Board of Louisiana (SPBLA) is the state agency responsible for
licensing master and journeyman plumbers and enforcing plumbing regulations throughout Louisiana.
Question 2
Under Louisiana law, what is the minimum slope requirement for a 3-inch horizontal drainage pipe?
A. 1/16 inch per foot
B. 1/8 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
🟢 Correct answer: C
🔴 Explanation: Per the adopted plumbing code, horizontal drainage pipes 3 inches or smaller require
a minimum slope of 1/4 inch per foot to ensure adequate flow and prevent clogs.
Question 3
What is the primary function of a plumbing vent system?
A. Increase water pressure to fixtures
B. Prevent trap siphonage and admit air into the drainage system
C. Filter waste materials from sewage
D. Heat water for distribution
🟢 Correct answer: B
🔴 Explanation: Vent systems equalize air pressure within the drainage system, protecting trap seals
from siphonage and allowing wastewater to flow freely.
,Question 4
Which Louisiana statute establishes the requirements for plumber licensing and regulation?
A. RS 37:1361 et seq.
B. RS 40:1730 et seq.
C. RS 9:4801 et seq.
D. RS 38:2211 et seq.
🟢 Correct answer: A
🔴 Explanation: Louisiana Revised Statute 37:1361 et seq. governs the licensing and regulation of
plumbers and plumbing contractors in the state.
Question 5
A plumbing contractor is installing a water supply system. Excessive incoming water pressure is
damaging fixtures. Which device should be installed?
A. Vacuum breaker
B. Water hammer arrestor
C. Pressure-reducing valve
D. Backwater valve
🟢 Correct answer: C
🔴 Explanation: A pressure-reducing valve regulates downstream water pressure when incoming
pressure exceeds acceptable operating limits, protecting fixtures and piping.
Question 6
Per the Louisiana Plumbing Code, what is the minimum trap seal depth for a plumbing fixture?
A. 1/2 inch
B. 1 inch
C. 2 inches
D. 4 inches
🟢 Correct answer: C
, 🔴 Explanation: A minimum trap seal depth of 2 inches is required to maintain an effective barrier
against sewer gases entering the building.
Question 7
Which license classification is required for a person who engages in the business of plumbing in
Louisiana?
A. Journeyman Plumber
B. Master Plumber
C. Apprentice Plumber
D. Residential Plumber Limited
🟢 Correct answer: B
🔴 Explanation: Only a licensed Master Plumber may engage in the business of plumbing, including
contracting for plumbing work and supervising journeymen.
Question 8
What is the maximum distance permitted between cleanouts in a horizontal drainage line?
A. 50 feet
B. 75 feet
C. 100 feet
D. 125 feet
🟢 Correct answer: C
🔴 Explanation: Cleanouts must be installed at intervals not exceeding 100 feet in horizontal drainage
lines to provide adequate access for cleaning and inspection.
Question 9
A journeyman plumber may perform plumbing work only under what condition?
A. When employed by a licensed master plumber
B. When working independently without supervision
C. When the work is limited to residential properties
