ICC Plumbing Plans Examiner Practice
Exam (ICC P2/PB-related competency
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which code primarily governs plumbing systems in ICC plumbing plan
review?
A. International Mechanical Code
B. International Plumbing Code
C. International Fire Code
D. International Building Code
Correct Answer: B. International Plumbing Code
Rationale: The International Plumbing Code (IPC) is the primary model code
,used for plumbing system design, installation, and plan review in ICC
jurisdictions.
2. The minimum slope for a 3-inch horizontal soil pipe is typically:
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: B. 1/8 inch per foot
Rationale: IPC generally permits 1/8 inch per foot slope for 3-inch and
larger horizontal drainage piping under specific sizing conditions.
3. Which fixture requires a trap?
A. Water heater
B. Lavatory
C. Main water line
D. Roof drain
Correct Answer: B. Lavatory
Rationale: Plumbing fixtures must be individually trapped to prevent sewer
gases from entering occupied spaces.
4. What is the minimum vent pipe size for a water closet?
,A. 1/2 inch
B. 3/4 inch
C. 1 inch
D. 1-1/2 inch
Correct Answer: C. 1 inch
Rationale: The IPC sets minimum vent sizes based on fixture units, with 1-
inch often required as the minimum for water closet venting systems
depending on design.
5. The primary purpose of a plumbing vent system is to:
A. Increase water pressure
B. Prevent pipe corrosion
C. Allow sewer gas escape and maintain trap seal
D. Drain stormwater
Correct Answer: C. Allow sewer gas escape and maintain trap seal
Rationale: Vent systems protect trap seals and equalize air pressure in
drainage systems.
6. What is the maximum vertical distance a trap may be installed below a
fixture outlet?
A. 12 inches
B. 24 inches
, C. 36 inches
D. 60 inches
Correct Answer: C. 24 inches
Rationale: Excessive distance between fixture outlet and trap can lead to
trap seal loss and is limited by code.
7. Which of the following is considered a fixture unit?
A. Pipe diameter
B. Drainage load value
C. Water pressure
D. Pipe material strength
Correct Answer: B. Drainage load value
Rationale: Fixture units quantify probable discharge rates for sizing
drainage systems.
8. A grease interceptor is typically required for:
A. Residential bathrooms
B. Commercial kitchens
C. Laundry rooms
D. Roof drainage systems
Exam (ICC P2/PB-related competency
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which code primarily governs plumbing systems in ICC plumbing plan
review?
A. International Mechanical Code
B. International Plumbing Code
C. International Fire Code
D. International Building Code
Correct Answer: B. International Plumbing Code
Rationale: The International Plumbing Code (IPC) is the primary model code
,used for plumbing system design, installation, and plan review in ICC
jurisdictions.
2. The minimum slope for a 3-inch horizontal soil pipe is typically:
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: B. 1/8 inch per foot
Rationale: IPC generally permits 1/8 inch per foot slope for 3-inch and
larger horizontal drainage piping under specific sizing conditions.
3. Which fixture requires a trap?
A. Water heater
B. Lavatory
C. Main water line
D. Roof drain
Correct Answer: B. Lavatory
Rationale: Plumbing fixtures must be individually trapped to prevent sewer
gases from entering occupied spaces.
4. What is the minimum vent pipe size for a water closet?
,A. 1/2 inch
B. 3/4 inch
C. 1 inch
D. 1-1/2 inch
Correct Answer: C. 1 inch
Rationale: The IPC sets minimum vent sizes based on fixture units, with 1-
inch often required as the minimum for water closet venting systems
depending on design.
5. The primary purpose of a plumbing vent system is to:
A. Increase water pressure
B. Prevent pipe corrosion
C. Allow sewer gas escape and maintain trap seal
D. Drain stormwater
Correct Answer: C. Allow sewer gas escape and maintain trap seal
Rationale: Vent systems protect trap seals and equalize air pressure in
drainage systems.
6. What is the maximum vertical distance a trap may be installed below a
fixture outlet?
A. 12 inches
B. 24 inches
, C. 36 inches
D. 60 inches
Correct Answer: C. 24 inches
Rationale: Excessive distance between fixture outlet and trap can lead to
trap seal loss and is limited by code.
7. Which of the following is considered a fixture unit?
A. Pipe diameter
B. Drainage load value
C. Water pressure
D. Pipe material strength
Correct Answer: B. Drainage load value
Rationale: Fixture units quantify probable discharge rates for sizing
drainage systems.
8. A grease interceptor is typically required for:
A. Residential bathrooms
B. Commercial kitchens
C. Laundry rooms
D. Roof drainage systems
