ICC P1 RESIDENTIAL PLUMBING INSPECTOR EXAM
Complete Study Guide (150+ Questions)
Multiple Choice with Answers & Rationales
Latest Update
Rated A+
EXAM OVERVIEW
The ICC P1 Residential Plumbing Inspector certification is
one of the four prerequisite exams required for the R5
Residential Combination Inspector (RCI) designation .
This certification validates proficiency in inspecting
plumbing systems in one- and two-family dwellings,
townhouses, and their accessory structures.
Feature Details
2024 International Residential Code (IRC) –
Primary Reference
Chapters 25-33
Number of
60
Questions
,Feature Details
Time Allowed 2 hours (120 minutes)
Format Open Book, Multiple Choice
Passing Score 75% (45 correct answers)
Exam ID P1
Exam Content Areas :
• Sanitary Drainage (23%) – 13-14 questions
• Vents (22%) – 13 questions
• Water Supply and Distribution (21%) – 13 questions
• General Requirements (14%) – 8 questions
• Water Heaters (12%) – 7 questions
• Fixtures (8%) – 5 questions
SECTION 1: GENERAL REQUIREMENTS (Questions 1-20)
1. What is the minimum slope required for a horizontal
drainage pipe 3 inches or smaller in diameter?
,A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Answer: B
Rationale: Most plumbing codes require a minimum
slope of 1/4 inch per foot for small horizontal drainage
piping to ensure proper gravity flow and prevent solids
from settling .
2. What is the minimum slope required for a 4-inch
horizontal drain line?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/16 inch per foot
D. 1 inch per foot
Answer: A
Rationale: Larger diameter pipes (4 inches and larger) are
permitted a minimum slope of 1/8 inch per foot because
the larger cross-section allows solids to flow at a reduced
slope .
, 3. What is the purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Increase flow rate
D. Filter solids from wastewater
Answer: B
Rationale: A trap retains a water seal (typically 2-4
inches) that blocks sewer gases from entering occupied
spaces while allowing wastewater to pass through .
4. What is the minimum trap seal depth required by
most codes?
A. 1 inch
B. 1.5 inches
C. 2 inches
D. 4 inches
Answer: C
Complete Study Guide (150+ Questions)
Multiple Choice with Answers & Rationales
Latest Update
Rated A+
EXAM OVERVIEW
The ICC P1 Residential Plumbing Inspector certification is
one of the four prerequisite exams required for the R5
Residential Combination Inspector (RCI) designation .
This certification validates proficiency in inspecting
plumbing systems in one- and two-family dwellings,
townhouses, and their accessory structures.
Feature Details
2024 International Residential Code (IRC) –
Primary Reference
Chapters 25-33
Number of
60
Questions
,Feature Details
Time Allowed 2 hours (120 minutes)
Format Open Book, Multiple Choice
Passing Score 75% (45 correct answers)
Exam ID P1
Exam Content Areas :
• Sanitary Drainage (23%) – 13-14 questions
• Vents (22%) – 13 questions
• Water Supply and Distribution (21%) – 13 questions
• General Requirements (14%) – 8 questions
• Water Heaters (12%) – 7 questions
• Fixtures (8%) – 5 questions
SECTION 1: GENERAL REQUIREMENTS (Questions 1-20)
1. What is the minimum slope required for a horizontal
drainage pipe 3 inches or smaller in diameter?
,A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Answer: B
Rationale: Most plumbing codes require a minimum
slope of 1/4 inch per foot for small horizontal drainage
piping to ensure proper gravity flow and prevent solids
from settling .
2. What is the minimum slope required for a 4-inch
horizontal drain line?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/16 inch per foot
D. 1 inch per foot
Answer: A
Rationale: Larger diameter pipes (4 inches and larger) are
permitted a minimum slope of 1/8 inch per foot because
the larger cross-section allows solids to flow at a reduced
slope .
, 3. What is the purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Increase flow rate
D. Filter solids from wastewater
Answer: B
Rationale: A trap retains a water seal (typically 2-4
inches) that blocks sewer gases from entering occupied
spaces while allowing wastewater to pass through .
4. What is the minimum trap seal depth required by
most codes?
A. 1 inch
B. 1.5 inches
C. 2 inches
D. 4 inches
Answer: C
