JOURNEYMAN PLUMBER PRACTICE
EXAM 2 QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2025
1. What is the minimum size of a building sewer allowed by most plumbing
codes?
A. 2 inches
B. 4 inches
C. 3 inches
D. 6 inches
Most plumbing codes require a minimum 4-inch building sewer to handle the
waste load from a typical residence or building.
2. A trap seal should be a minimum of:
A. 1 inch
B. 2 inches
C. 3 inches
,D. 4 inches
A 2-inch trap seal is standard and prevents sewer gases from entering the
building.
3. What is the minimum size of a vent for a water closet?
A. 1½ inches
B. 2 inches
C. 3 inches
D. 4 inches
The minimum size for a vent on a water closet is 1½ inches according to most
codes.
4. What material is commonly used for gas piping in residential applications?
A. PVC
B. CPVC
C. Black steel
D. Copper
Black steel is commonly used due to its strength and gas-tight properties.
5. The distance a trap can be from its vent (developed length) for a 1½" pipe is
typically limited to:
A. 2 feet
B. 6 feet
C. 8 feet
,D. 10 feet
Most codes allow a maximum developed length of 6 feet for a 1½" trap arm to
its vent.
6. A sanitary tee is used in drainage systems to:
A. Connect a horizontal branch to a vertical stack
B. Connect vent piping
C. Terminate cleanouts
D. Transition from copper to plastic
Sanitary tees are used to connect horizontal drains to vertical stacks.
7. A plumbing system must include a cleanout at the base of every:
A. Vent stack
B. Soil or waste stack
C. Water riser
D. Fixture branch
Cleanouts at the base of soil or waste stacks allow maintenance and blockage
removal.
8. Which of the following fixtures requires a trap?
A. Roof drain
B. Floor drain
C. Indirect waste receptor
, D. All of the above
All of these fixtures require a trap to prevent sewer gas from escaping.
9. What is the minimum slope required 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
The minimum slope for 3-inch or larger drainage pipes is 1/8 inch per foot.
10. What is the maximum number of water closets allowed on a 3-inch
horizontal branch in a residential application?
A. 2
B. 3
C. 4
D. 5
A 3-inch horizontal branch typically serves up to 3 water closets depending on
local code.
11. Which of the following is NOT permitted for use in potable water systems?
A. Copper
B. CPVC
C. Lead pipe
EXAM 2 QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2025
1. What is the minimum size of a building sewer allowed by most plumbing
codes?
A. 2 inches
B. 4 inches
C. 3 inches
D. 6 inches
Most plumbing codes require a minimum 4-inch building sewer to handle the
waste load from a typical residence or building.
2. A trap seal should be a minimum of:
A. 1 inch
B. 2 inches
C. 3 inches
,D. 4 inches
A 2-inch trap seal is standard and prevents sewer gases from entering the
building.
3. What is the minimum size of a vent for a water closet?
A. 1½ inches
B. 2 inches
C. 3 inches
D. 4 inches
The minimum size for a vent on a water closet is 1½ inches according to most
codes.
4. What material is commonly used for gas piping in residential applications?
A. PVC
B. CPVC
C. Black steel
D. Copper
Black steel is commonly used due to its strength and gas-tight properties.
5. The distance a trap can be from its vent (developed length) for a 1½" pipe is
typically limited to:
A. 2 feet
B. 6 feet
C. 8 feet
,D. 10 feet
Most codes allow a maximum developed length of 6 feet for a 1½" trap arm to
its vent.
6. A sanitary tee is used in drainage systems to:
A. Connect a horizontal branch to a vertical stack
B. Connect vent piping
C. Terminate cleanouts
D. Transition from copper to plastic
Sanitary tees are used to connect horizontal drains to vertical stacks.
7. A plumbing system must include a cleanout at the base of every:
A. Vent stack
B. Soil or waste stack
C. Water riser
D. Fixture branch
Cleanouts at the base of soil or waste stacks allow maintenance and blockage
removal.
8. Which of the following fixtures requires a trap?
A. Roof drain
B. Floor drain
C. Indirect waste receptor
, D. All of the above
All of these fixtures require a trap to prevent sewer gas from escaping.
9. What is the minimum slope required 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
The minimum slope for 3-inch or larger drainage pipes is 1/8 inch per foot.
10. What is the maximum number of water closets allowed on a 3-inch
horizontal branch in a residential application?
A. 2
B. 3
C. 4
D. 5
A 3-inch horizontal branch typically serves up to 3 water closets depending on
local code.
11. Which of the following is NOT permitted for use in potable water systems?
A. Copper
B. CPVC
C. Lead pipe
