LATEST COMMERCIAL PLUMBING
INSPECTOR (P2) CERTIFICATION EXAM
OFFERED BY INTERNATIONAL CODE
COUNCIL (ICC) | Q&A WITH RATIONALES
1. A commercial building has a hot water
recirculation system that returns unused hot water to
the water heater. What type of valve is required at the
point where the return line connects to the water
heater to prevent backflow?
A) Gate valve
B) Globe valve
C) Check valve
D) Ball valve
Correct answer: C
Rationale: A check valve prevents backflow in the
return line, ensuring water flows in the intended
direction only.
2. After installing a new commercial drainage system,
what is the minimum test pressure required for a
water test?
A) 5 feet of head
,B) 10 feet of head
C) 20 feet of head
D) 30 feet of head
Correct answer: B
Rationale: The IPC requires that a water test be
applied to the drainage system at a minimum
pressure equivalent to 10 feet of head (4.33 psi)
above the highest point.
3. According to the IPC, what is the maximum
distance a cleanout cover can be below grade
without requiring an extension to grade?
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
Correct answer: B
Rationale: The IPC allows a cleanout cover to be up
to 12 inches below finished grade without an
extension, provided the location is clearly marked.
4. A 3-inch building drain has a developed length of
80 feet. What is the minimum slope required?
,A) 1/8 inch per foot
B) 1/4 inch per foot
C) 1/2 inch per foot
D) 1 inch per foot
Correct answer: A
Rationale: The minimum slope for a 3-inch building
drain is 1/8 inch per foot. For a 2-inch drain, it is 1/4
inch per foot.
5. What is the primary purpose of a cleanout in a
commercial sanitary drainage system?
A) To provide an air intake for the system
B) To allow access for removing obstructions and
cleaning the pipe
C) To serve as a drain for condensate lines
D) To act as a backflow preventer
Correct answer: B
Rationale: The primary purpose of a cleanout is to
provide access to the drainage system for clearing
stoppages and performing maintenance.
6. A 4-inch building drain requires a cleanout at its
base. According to IPC, the cleanout must be located
, no more than how many feet from the building
foundation?
A) 1 foot
B) 2 feet
C) 5 feet
D) 10 feet
Correct answer: C
Rationale: The IPC requires a cleanout to be located
outside the building wall at the point where the
building drain connects to the building sewer, within
5 feet of the foundation.
### Section 2: Fixtures (Questions 7-16)
7. A commercial building has a breakroom sink. What
is the minimum trap size required for this fixture?
A) 1 inch
B) 1-1/2 inches
C) 2 inches
D) 3 inches
Correct answer: B
Rationale: Domestic style breakroom sinks in
commercial occupancies require a minimum trap size
INSPECTOR (P2) CERTIFICATION EXAM
OFFERED BY INTERNATIONAL CODE
COUNCIL (ICC) | Q&A WITH RATIONALES
1. A commercial building has a hot water
recirculation system that returns unused hot water to
the water heater. What type of valve is required at the
point where the return line connects to the water
heater to prevent backflow?
A) Gate valve
B) Globe valve
C) Check valve
D) Ball valve
Correct answer: C
Rationale: A check valve prevents backflow in the
return line, ensuring water flows in the intended
direction only.
2. After installing a new commercial drainage system,
what is the minimum test pressure required for a
water test?
A) 5 feet of head
,B) 10 feet of head
C) 20 feet of head
D) 30 feet of head
Correct answer: B
Rationale: The IPC requires that a water test be
applied to the drainage system at a minimum
pressure equivalent to 10 feet of head (4.33 psi)
above the highest point.
3. According to the IPC, what is the maximum
distance a cleanout cover can be below grade
without requiring an extension to grade?
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
Correct answer: B
Rationale: The IPC allows a cleanout cover to be up
to 12 inches below finished grade without an
extension, provided the location is clearly marked.
4. A 3-inch building drain has a developed length of
80 feet. What is the minimum slope required?
,A) 1/8 inch per foot
B) 1/4 inch per foot
C) 1/2 inch per foot
D) 1 inch per foot
Correct answer: A
Rationale: The minimum slope for a 3-inch building
drain is 1/8 inch per foot. For a 2-inch drain, it is 1/4
inch per foot.
5. What is the primary purpose of a cleanout in a
commercial sanitary drainage system?
A) To provide an air intake for the system
B) To allow access for removing obstructions and
cleaning the pipe
C) To serve as a drain for condensate lines
D) To act as a backflow preventer
Correct answer: B
Rationale: The primary purpose of a cleanout is to
provide access to the drainage system for clearing
stoppages and performing maintenance.
6. A 4-inch building drain requires a cleanout at its
base. According to IPC, the cleanout must be located
, no more than how many feet from the building
foundation?
A) 1 foot
B) 2 feet
C) 5 feet
D) 10 feet
Correct answer: C
Rationale: The IPC requires a cleanout to be located
outside the building wall at the point where the
building drain connects to the building sewer, within
5 feet of the foundation.
### Section 2: Fixtures (Questions 7-16)
7. A commercial building has a breakroom sink. What
is the minimum trap size required for this fixture?
A) 1 inch
B) 1-1/2 inches
C) 2 inches
D) 3 inches
Correct answer: B
Rationale: Domestic style breakroom sinks in
commercial occupancies require a minimum trap size
