Practice Questions, Verified Answers &
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ALABAMA JOURNEYMAN PLUMBER EXAM 2026 - PRACTICE QUESTIONS
DOCUMENT OVERVIEW
• This comprehensive practice exam contains 200 carefully curated questions
designed to mirror the actual Alabama Journeyman Plumber Exam format, difficulty
level, and subject matter distribution.
• Use this material to identify knowledge gaps, build confidence through repetition,
and master both technical concepts and practical application scenarios that
examiners test most frequently.
QUESTION 1
What is the maximum distance a P-trap can be installed from a fixture drain
outlet according to the International Plumbing Code?
A) 2 feet
B) 4 feet
C) 6 feet
D) 8 feet
E) 10 feet
CORRECT ANSWER: C) 6 feet
RATIONALE: According to the International Plumbing Code (IPC) and Alabama
Plumbing Code, the maximum distance a trap can be installed from a fixture is 6
feet measured along the drain pipe. If the distance exceeds 6 feet, the trap seal
,may be broken due to siphonage or evaporation, which can allow sewer gases to
enter the building.
QUESTION 2
Which of the following is the minimum slope required for horizontal drainage
pipes in residential plumbing?
A) 1/8 inch per foot
B) 1/4 inch per foot
C) 1/2 inch per foot
D) 3/4 inch per foot
E) 1 inch per foot
CORRECT ANSWER: B) 1/4 inch per foot
RATIONALE: The International Plumbing Code requires a minimum slope of 1/4 inch
per foot for all horizontal drainage pipes. This slope ensures proper drainage
velocity and prevents stoppages. A slope of less than 1/4 inch per foot may result in
settling of solids, while slopes greater than 3/4 inch per foot can cause separation
of liquids and solids.
QUESTION 3
What is the primary purpose of a vent stack in a plumbing system?
A) To provide water supply to upper fixtures
B) To allow gases to escape and maintain atmospheric pressure in drain pipes
,C) To prevent backflow in the main sewer line
D) To filter debris from wastewater
E) To regulate water pressure throughout the building
CORRECT ANSWER: B) To allow gases to escape and maintain atmospheric
pressure in drain pipes
RATIONALE: The primary function of a vent stack is to allow sewer gases to escape
to the atmosphere while maintaining atmospheric pressure in the drainage system.
This prevents trap seals from being broken and allows waste to drain efficiently.
Without proper venting, drainage becomes sluggish and trap seals can be
siphoned, allowing sewer gases to enter the building.
QUESTION 4
Which type of pipe is most commonly used for water supply in modern
residential construction?
A) Galvanized steel
B) Cast iron
C) PVC
D) Copper
E) Lead
CORRECT ANSWER: D) Copper
RATIONALE: Copper is the most widely used material for water supply piping in
modern residential construction due to its durability, resistance to corrosion, and
ability to withstand high pressures and temperatures. While PVC is sometimes used
for cold water supplies in some jurisdictions, copper remains the standard in most
, areas and is required by many local codes. Lead piping is prohibited for drinking
water supplies.
QUESTION 5
What is the minimum diameter of a vent pipe for a water closet?
A) 1 1/4 inches
B) 1 1/2 inches
C) 2 inches
D) 3 inches
E) 4 inches
CORRECT ANSWER: B) 1 1/2 inches
RATIONALE: According to the IPC and Alabama Code, the minimum vent pipe
diameter for a water closet is 1 1/2 inches. This size is necessary to allow adequate
air circulation to maintain proper pressure balance in the drainage system and to
prevent trap seal loss. Smaller diameter vents may not provide sufficient ventilation
for a water closet.
QUESTION 6
What is the maximum horizontal distance a vent pipe can travel before
connecting to a main vent stack?
A) 8 feet
B) 15 feet