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100+ Free SC Plumber Contractor Practice Questions

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2026 Statistics

Key Facts: SC Plumber Contractor Exam

80 Q

Official Exam Questions

PSI SC Commercial Contractor CIB updated 5/15/2025

70%

Passing Score

PSI SC Commercial Contractor CIB updated 5/15/2025

4 hours

Time Allowed

PSI SC Commercial Contractor CIB updated 5/15/2025

USD 75

PSI Exam Fee

PSI SC Commercial Contractor CIB updated 5/15/2025

Open Book

Book Policy

PSI SC Commercial Contractor CIB updated 5/15/2025

South Carolina Plumber Contractor Examination is the official CLB/PSI open-book exam: 80 questions, 70% (56 of 80), 4 hours, USD 75 (bulletin updated 5/15/2025). Official delivery is English.

Sample SC Plumber Contractor Practice Questions

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

1On an accessible water closet in a South Carolina commercial toilet room, ICC A117.1 as referenced by the 2021 IPC requires the water-closet centerline to be how far from the adjacent side wall or partition?
A.12 inches to 15 inches
B.15 inches to 16 inches
C.16 inches to 18 inches
D.18 inches to 21 inches
Explanation: ICC A117.1 Section 604.2, applied through IPC Section 404, places an accessible water closet 16 inches minimum to 18 inches maximum from the side wall or partition to the fixture centerline. That range lines up the seat with the side grab bar and keeps the transfer clearances usable. The ordinary (non-accessible) IPC 405.3.1 side-wall minimum of 15 inches does not satisfy the accessible positioning rule.
2For an accessible lavatory serving a public restroom, what is the maximum height of the lavatory rim or counter surface above the finished floor?
A.30 inches
B.32 inches
C.34 inches
D.36 inches
Explanation: ICC A117.1 Section 606.3 limits accessible lavatory rims and counter surfaces to 34 inches maximum above the finished floor. Knee clearance of 27 inches minimum must still be provided below the bowl, and supply and waste piping must be insulated or otherwise configured to protect against contact. A 36-inch rim is a common cabinet height and fails the accessible maximum.
3In the 2021 IPC, developed length of piping is measured along which path?
A.The shortest horizontal plan distance between the two endpoints
B.The centerline of the pipe through fittings, including vertical offsets
C.The outside-of-insulation length, ignoring fitting takeouts
D.The vertical rise only, because horizontal runs are neglected
Explanation: IPC Chapter 2 defines developed length as the length of a pipeline measured along the centerline of the pipe and fittings. Vertical offsets, horizontal runs, and the sweep of fittings all count. Plan-view shortcuts and insulation jackets are not the measurement the vent, trap-arm, and water-supply tables use.
4A roof-mounted water heater sits 28 feet above the building water meter. Approximately how much static pressure is lost between the meter and the heater inlet? Use 0.433 psi per foot of elevation.
A.6.1 psi
B.8.7 psi
C.12.1 psi
D.28.0 psi
Explanation: Static head converts at 0.433 psi per foot of elevation. 28 ft × 0.433 psi/ft = 12.124 psi, which rounds to 12.1 psi. That loss must be subtracted from street pressure before friction, meter, and backflow losses are taken, or the heater will be short of the residual pressure required by IPC Table 604.3.
5A 45-degree offset must gain 12 inches of offset. Using the constant from Mathematics for Plumbers and Pipefitters, what travel length is required?
A.12.00 inches
B.13.86 inches
C.16.97 inches
D.24.00 inches
Explanation: For a 45-degree offset the travel equals the offset times 1.414. 12 × 1.414 = 16.968 inches, which rounds to 16.97 inches. The 1.414 constant is the square root of 2 and is the value Lee Smith’s 8th edition uses for 45-degree fitting offsets.
6Using the plumber’s cylinder formula gallons = 0.0408 × d² × L, how many gallons does 80 feet of 4-inch pipe hold if d is taken as 4.00 inches?
A.13.1 gallons
B.26.1 gallons
C.52.2 gallons
D.104.4 gallons
Explanation: Gallons = 0.0408 × (4.00)² × 80 = 0.0408 × 16 × 80 = 52.224 gallons. The constant 0.0408 converts a circular cross-section in inches and a length in feet into U.S. gallons and is the working formula in Mathematics for Plumbers and Pipefitters. Using the actual Schedule 40 ID of 4.026 inches changes the answer only slightly and is not required when the problem states d = 4.00 inches.
7Before excavating for a new building sewer in South Carolina, the excavator must notify SC 811 within which window?
A.The same working day the work starts
B.At least 24 hours, but not more than 48 hours, before work starts
C.Three to twelve full working days before the proposed start, not counting the day notice is given
D.Thirty calendar days before the proposed start
Explanation: The South Carolina Underground Facility Damage Prevention Act, administered through SC 811, requires notice three to twelve full working days before excavation begins, and the 2026 excavator rules exclude the day the ticket is placed. Locators then have that window to mark. Same-day or 24-hour notice does not give operators the statutory locate time.
8Under the current SC 811 excavator rules, the tolerance zone around a marked underground facility is measured as which of the following?
A.6 inches on each side of the paint mark
B.12 inches on each side of the paint mark
C.18 inches on each side of the outside of the facility only
D.24 inches on each side of the utility mark, plus one-half the facility diameter
Explanation: The 2026 SC 811 Excavator Manual defines the tolerance zone as 24 inches on either side of the utility mark plus one-half the diameter of the facility. Inside that zone only hand work or approved soft digging is allowed until the facility is visually cleared. Older 18-inch language was replaced by the May 22, 2026 damage-prevention amendments.
9On a commercial site, white temporary marking paint is used by the excavator to identify which of the following?
A.Electric power
B.Proposed excavation
C.Potable water
D.Sanitary sewer
Explanation: The APWA Uniform Color Code, used by SC 811, assigns white to the excavator’s proposed excavation or proposed construction. Yellow is gas, blue is potable water, green is sewer, and red is electric. White-lining the work area before the ticket is placed helps locators mark only the ground that will actually be opened.
10Under the 2021 IPC as adopted in South Carolina, a plumbing permit is required for which of the following?
A.Replacement of a listed residential lavatory faucet with another listed faucet on the same rough-in
B.Stoppage clearing that does not require cutting the piping
C.Installation of a new 3-inch building sewer from a commercial building to the public sewer
D.Replacement of a lavatory P-trap washer where the trap is not disturbed
Explanation: IPC Section 106 requires a permit for new plumbing systems and for the installation, enlargement, alteration, or repair of a building sewer. A new 3-inch commercial building sewer is new work and must be permitted and inspected. Minor stoppage clearing and like-for-like faucet or washer replacements that do not alter the piping are the kinds of ordinary repairs the code exempts.

About the SC Plumber Contractor Exam

The South Carolina Plumber Contractor Examination is the official CLB classification examination administered by PSI. The official exam has 80 scored questions. Passing is 70% (56 of 80) in 4 hours. The examination is open book. PSI lists USD 75 (Candidate Information Bulletin updated 5/15/2025). This commercial mechanical classification is distinct from the generic sc-plumber journeyman bank. Candidates must also pass Business Management and Law for Commercial Contractor. This bank is an English-language MCQ study adaptation. It does not replace required trade experience, board approval, or the official examination.

Assessment

Open-book computer-based multiple-choice. Allowed references include the 2021 International Plumbing Code or 2021 South Carolina Plumbing Code, 2021 IFGC with SC modifications or 2021 SC Fuel Gas Code, Mathematics for Plumbers and Pipefitters (8th, 2013), and the South Carolina 811 Excavator Manual.

Time Limit

4 hours

Passing Score

70% (56 of 80)

Exam Fee

USD 75 (PSI Services LLC (for the South Carolina Contractor's Licensing Board))

SC Plumber Contractor Exam Content Outline

3%

ADA Accessibility

ADA Accessibility (1 item)

11%

General Plumbing Knowledge and Regulations

General Plumbing Knowledge (6 items) and Regulations (3 items)

7%

Materials, Joints, and Supports

Hangers, materials, joints and connections (6 items)

9%

Fixtures and Water Heaters

Fixtures and equipment (3 items) and water heaters (4 items)

5%

Water Supply and Backflow

Water supply and distribution (3 items) and backflow (1 item)

24%

Drainage, Vents, and Storm

Sanitary drainage, cleanouts, indirect waste, venting, traps, storm piping (19 items)

6%

Developed Length

Plumbing - Developed Length (5 items)

21%

Isometric Analysis

DWV, water-supply, and roof-drain isometric analysis (17 items)

3%

Pipe Assembly and Valves

Pipe assembly and valves (2 items)

11%

Fuel Gas

General fuel knowledge (3), natural gas (3), and LP gas (3) (9 items)

How to Pass the SC Plumber Contractor Exam

What You Need to Know

  • Passing score: 70% (56 of 80)
  • Assessment: Open-book computer-based multiple-choice. Allowed references include the 2021 International Plumbing Code or 2021 South Carolina Plumbing Code, 2021 IFGC with SC modifications or 2021 SC Fuel Gas Code, Mathematics for Plumbers and Pipefitters (8th, 2013), and the South Carolina 811 Excavator Manual.
  • Time limit: 4 hours
  • Exam fee: USD 75

Keys to Passing

  • Work through all 100 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

SC Plumber Contractor Study Tips from Top Performers

1Distribute study time to the official PSI content outline (bulletin updated 5/15/2025)
2Use only the PSI-listed references; temporary tabs such as Post-it notes are prohibited
3Pass Business Management and Law for Commercial Contractor in addition to this technical examination
4This bank is an English-language MCQ study aid, not an official PSI form

Frequently Asked Questions

How many questions are on the South Carolina Plumber Contractor Examination?

The official PSI examination has 80 scored questions. Passing is 70% (56 of 80) within 4 hours (Commercial Contractor Candidate Information Bulletin updated 5/15/2025).

How much does this PSI examination cost?

PSI lists USD 75 for this examination. The South Carolina Contractor's Licensing Board charges a separate USD 350 license application fee for general and mechanical contractor licenses.

Is this examination open book?

Yes. PSI lists the South Carolina commercial contractor examinations as open book. Listed references include the 2021 IPC or 2021 South Carolina Plumbing Code and the 2021 IFGC or 2021 SC Fuel Gas Code.

Is this the same as the South Carolina journeyman plumber exam?

No. This is the official CLB commercial Plumber classification examination (80 questions, 70% in 4 hours). The generic sc-plumber bank is a journeyman identity and is not this classification outline.