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2026 Statistics

Key Facts: BOABC Plumbing Level I Exam

100

Total Questions

BOABC Exam Specifications

Scaled 80

Passing Score

BOABC Guidelines

2.5 Hours

Time Limit

BOABC Guidelines

$295

Fee (CAD)

BOABC Fee Schedule

Part 2

BCPC 2024 Scope

Exam Syllabus

The BOABC Plumbing Official Level I exam consists of 100 multiple-choice questions with a 2.5-hour time limit. It is an open-book exam based on the BC Plumbing Code 2024, requiring a scaled score of 80 to pass.

Sample BOABC Plumbing Level I Practice Questions

Try these sample questions to test your BOABC Plumbing Level I exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Under the BC Plumbing Code 2024, what is the minimum slope required for a horizontal sanitary drainage pipe with a size of 3 inches or less?

A.1 in 50 (2%)

B.1 in 100 (1%)

C.1 in 25 (4%)

D.1 in 200 (0.5%)

Explanation: According to the BC Plumbing Code 2024, Section 2.4.8.1, the minimum slope for a horizontal drainage pipe of 3 inches or less in size is 1 in 50 (2%). This slope ensures adequate velocity to carry suspended solids and prevent blockages. Pipes larger than 3 inches are permitted a minimum slope of 1 in 100 (1%).

2Under the BC Plumbing Code 2024, what is the maximum spacing between cleanouts on a horizontal drainage pipe of 3 inches or less?

A.15 metres

B.30 metres

C.7.5 metres

D.10 metres

Explanation: Section 2.4.7.2 of the BC Plumbing Code 2024 states that the maximum spacing between cleanouts on a horizontal drainage pipe of 3 inches or less is 15 metres. For piping larger than 3 inches, the maximum spacing is 30 metres. This ensures maintenance equipment can effectively reach all sections.

3Under the BC Plumbing Code 2024, when a fixture is supplied with separate hot and cold water supply controls, how must the two controls be arranged?

A.Hot on the left, cold on the right

B.Cold on the left, hot on the right

C.Hot on top, cold on the bottom

D.Either arrangement is acceptable

Explanation: Section 2.6.1.1 of the BC Plumbing Code 2024 requires that fixtures supplied with separate hot and cold water controls have the hot water control on the left and the cold water control on the right. Standardizing the layout helps users avoid accidental scalding when operating an unfamiliar fixture.

4Under Table 2.4.10.2 of the BC Plumbing Code 2024, what is the minimum nominal trap size for a domestic kitchen sink?

A.1.5 inches (38 mm)

B.1.25 inches (32 mm)

C.2.0 inches (50 mm)

D.3.0 inches (75 mm)

Explanation: According to Table 2.4.10.2 of the BC Plumbing Code 2024, the minimum nominal trap size for a domestic kitchen sink (single or double bowl) is 1.5 inches (38 mm). This size provides adequate capacity for residential food waste and dishwashing water loads.

5What is the maximum horizontal support spacing required for a 3-inch ABS drainage pipe under the BC Plumbing Code 2024?

A.1.2 metres

B.2.0 metres

C.1.5 metres

D.2.5 metres

Explanation: According to Section 2.3.4.5 and Table 2.3.4.5 of the BC Plumbing Code 2024, plastic piping (including ABS and PVC) must be supported horizontally at intervals not exceeding 1.2 metres. Adequate support is critical for plastic pipes to prevent sagging, which can create pockets and lead to flow restrictions.

6What is the minimum clearance required in front of a cleanout serving a 4-inch drainage pipe under the BC Plumbing Code 2024?

A.450 mm

B.300 mm

C.600 mm

D.150 mm

Explanation: Section 2.4.7.3 of the BC Plumbing Code 2024 specifies that a minimum clearance of 450 mm must be provided in front of cleanouts on pipes that are 3 inches or larger. This space allows plumbers sufficient room to insert, manipulate, and clean the line with drainage rods.

7What type of cement is required under the BC Plumbing Code 2024 when joining ABS piping to PVC piping in a non-pressure drainage application?

A.Transition cement

B.Standard ABS solvent weld cement

C.Standard PVC solvent weld cement

D.Thread sealant or silicone

Explanation: According to Section 2.2.2 of the BC Plumbing Code 2024, joints between ABS and PVC piping must be made using a certified transition cement (usually green in color) in non-pressure applications. Using regular ABS or PVC cement will not form a proper chemical weld, leading to joint failure over time.

8Under the BC Plumbing Code 2024, what is the fundamental requirement for any connection made to a potable water system?

A.It must be designed and installed so that non-potable water or contaminants cannot enter the potable system

B.It must be joined only with lead-free solder

C.It must be located above the ceiling of the lowest storey

D.It must be painted blue for identification

Explanation: Section 2.6.2.1 (Protection from Contamination) of the BC Plumbing Code 2024 requires that connections to potable water systems be designed and installed so that non-potable water or substances that could render the water non-potable cannot enter the system. This principle is the basis for all cross-connection and backflow-prevention requirements.

9Where a backwater valve is installed to protect fixtures located below the level of the adjoining street manhole, where must it be positioned?

A.On the branch serving those specific fixtures only

B.On the main building drain serving all fixtures

C.Outside the building on the building sewer line

D.On the vent stack serving the fixtures

Explanation: Section 2.4.6.4 of the BC Plumbing Code 2024 states that backwater valves protecting fixtures below street level must be installed on the branch serving those specific fixtures only. Installing a backwater valve on the main building drain would trap sewer gases or cause fixture overflow when the valve closes during a sewer backup.

10What is the maximum slope or fall permitted for a trap arm under the BC Plumbing Code 2024 to prevent siphoning of the trap?

A.One pipe diameter

B.Two pipe diameters

C.1 in 25 (4%)

D.50 mm total fall

Explanation: According to Section 2.5.6.3 of the BC Plumbing Code 2024, the total fall of a trap arm between the trap weir and the vent connection must not exceed one pipe diameter. If the fall exceeds one pipe diameter, the hydraulic profile can create a siphon, drawing the seal out of the trap.

About the BOABC Plumbing Level I Exam

The BOABC Plumbing Official Level I Examination is a professional certification exam administered by the Building Officials' Association of British Columbia. This exam validates the candidate's proficiency in applying the British Columbia Plumbing Code (BCPC) 2024, focusing specifically on drainage and venting systems (Part 2). Key subjects include sizing and design of drainage systems, venting configurations (such as wet venting, circuit venting, and trap venting), material compliance, joint methods, and administrative requirements. This exam is essential for plumbing inspectors and municipal officials enforcing plumbing codes in BC.

Assessment

100 multiple-choice questions (Open-book, computer-based)

Time Limit

2.5 hours

Passing Score

Scaled score of 80

Exam Fee

$295 CAD plus GST (Building Officials' Association of British Columbia (BOABC))

BOABC Plumbing Level I Exam Content Outline

40%

Drainage Systems

Covers design, sizing, installation, cleanouts, interceptors, backwater valves, and slope of sanitary and storm drainage systems.

40%

Venting Systems

Covers design, sizing, and configuration of wet venting, circuit venting, stack venting, relief vents, yoke vents, and terminal heights.

10%

Materials and Joints

Covers compliance standards for piping materials (ABS, PVC, copper, cast iron), joint methods, pipe hangers, support spacing, and thermal expansion.

10%

Administration and Inspections

Covers code definitions, compliance, permit requirements, testing procedures (water/air/smoke), and inspection standards.

How to Pass the BOABC Plumbing Level I Exam

What You Need to Know

Passing score: Scaled score of 80
Assessment: 100 multiple-choice questions (Open-book, computer-based)
Time limit: 2.5 hours
Exam fee: $295 CAD plus GST

Keys to Passing

Complete 500+ practice questions
Score 80%+ consistently before scheduling
Focus on highest-weighted sections
Use our AI tutor for tough concepts

BOABC Plumbing Level I Study Tips from Top Performers

1Familiarize yourself with BCPC 2024 Table 2.4.9.3 (fixture units and drainage capacities) and Table 2.5.8.4 (vent pipe sizing). Tab these pages in your code book for quick reference.

2Understand the difference between a wet vent, a circuit vent, and a dual vent, and pay attention to their specific sizing rules.

3Practice converting flow rates from continuous-flow devices to equivalent fixture units (1 FU = 1.9 L/min).

4Review the testing standards in Section 2.7.2, specifically the pressures and durations for water and air tests on plastic versus metal piping.

5Manage your time carefully: with 100 questions in 2.5 hours, you have an average of 1.5 minutes per question. Knowing the code layout is critical.

Frequently Asked Questions

Is the BOABC Plumbing Official Level I exam open book?

Yes, the exam is open book. Candidates are permitted and highly encouraged to have a physical or approved digital copy of the British Columbia Plumbing Code 2024 during the examination.

What is the passing score for the BOABC Plumbing Level I exam?

The passing threshold is a scaled score of 80. This is not a simple percentage of correct answers, but rather a psychometrically scaled score based on question difficulty.

What parts of the BC Plumbing Code does this exam focus on?

The Level I exam (BC-P1, one- and two-family dwellings) concentrates on drainage and venting systems under Part 2 of the British Columbia Plumbing Code 2024, and also covers basic potable water systems (approved materials, sizing, and protection against contamination/backflow). Larger and more complex water-distribution design is emphasized more heavily at Level II (BC-P2).

Can I take the exam online?

Yes. BOABC administers its qualification exams online through the PRONTO remote online proctoring system, allowing candidates to complete the test from home or office, provided they meet computer system and webcam monitoring requirements.