Why It's Worth Passing in Portland
- Median plumber salary in Portland: $63,800/yr
- Experienced earners: up to $94,000/yr
- Local job growth: +6%
- Open positions: 1,000+
What to Expect on the Exam
The plumber licensing exam covers code requirements, technical fundamentals, safety standards, and applied calculations. CraftPATH's free prep mirrors the real exam format with multiple-choice questions, instant feedback, and topic-by-topic drills.
Plumbing Code
International Plumbing Code (IPC), Uniform Plumbing Code (UPC), local amendments, and code compliance for residential and commercial projects.
Drainage Systems
Drain-waste-vent (DWV) systems, pipe sizing, slope calculations, trap requirements, and venting methods.
Water Supply
Water distribution design, pipe sizing, pressure calculations, backflow prevention, and water heater installation.
Fixtures & Appliances
Fixture unit calculations, installation requirements, accessibility standards, and appliance connections.
Safety & Materials
Material specifications, joining methods, OSHA safety requirements, and excavation safety.
- Length: 80–110 questions
- Time limit: 4–5 hours
- Passing score: 70–75%
- Exam fee: $50–$150 (state-dependent)
- Format: Open-book (IPC/UPC code book allowed in most states)
Sample Plumber Practice Questions
Six questions from the free plumber bank, with the answer and the reasoning behind it.
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1. What causes a foul odor from a drain? (Drainage Systems)
- A. High water pressure
- B. Dried out P-trap or blocked vent
- C. New pipes
- D. Cold water
Answer: B — Dried out P-trap or blocked vent
Foul drain odors usually indicate a dried-out P-trap (no water seal) or a blocked vent allowing sewer gas in.
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2. What is the minimum water heater temperature to prevent Legionella? (Safety)
- A. 100°F
- B. 110°F
- C. 120°F
- D. 140°F
Answer: D — 140°F
Water should be stored at 140°F to prevent Legionella bacteria growth, but delivered at 120°F via mixing valve.
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3. What pipe material is best for underground water supply? (Water Supply)
- A. Copper only
- B. PEX or HDPE
- C. Cast iron
- D. Galvanized steel
Answer: B — PEX or HDPE
PEX and HDPE are preferred for underground water supply due to flexibility and corrosion resistance.
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4. What is the minimum vent pipe size? (Plumbing Code)
- A. 3/4 inch
- B. 1 inch
- C. 1-1/4 inches
- D. 2 inches
Answer: C — 1-1/4 inches
The minimum vent pipe size is typically 1-1/4 inches, though it varies by fixture and code.
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5. What is the maximum temperature for PEX pipe? (Plumbing Code)
- A. 140°F
- B. 160°F
- C. 180°F
- D. 200°F
Answer: D — 200°F
PEX is rated for a maximum of 200°F, making it suitable for both hot and cold water supply.
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6. What causes gurgling sounds in drains? (Drainage Systems)
- A. High water pressure
- B. Inadequate venting
- C. Hot water
- D. New pipes
Answer: B — Inadequate venting
Gurgling sounds indicate inadequate venting, causing air to be pulled through trap water seals.
A Study Plan That Fits a Portland Work Week
- Weeks 1–2: untimed topic drills across every domain to find weak areas.
- Weeks 3–5: work the weak topics with the code book open, timing each lookup.
- Weeks 6–8: timed full-length rounds until you hold 85% consistently.
- Final week: review missed questions and confirm your Oregon application status.
- Know your local plumbing code — IPC vs UPC varies by state
- Master pipe sizing tables and fixture unit calculations
- Practice DWV system layout questions extensively
- Memorize key code sections for quick reference during the exam
Local Context for Portland
Portland's heavy rainfall and aging Victorian-era plumbing create consistent repair and upgrade demand.
Plumber Exam Questions from Portland Candidates
How much do plumbers make in Portland?
The median plumber salary in Portland, OR is $63,800. Entry-level roles start near $37,000 and experienced licensees reach $94,000. Passing the licensing exam is the gate to the upper half of that range.
Where can I take the plumber exam near Portland?
Portland, OR candidates test at state-approved centers scheduled through the Oregon licensing board or its exam vendor. Local programs such as UA Local 290 or Clackamas Community College can point you to the nearest seat and confirm the paperwork you need before applying.
How long should I study before testing in Oregon?
Most candidates give it 8 to 12 weeks at about an hour a night: untimed topic drills first, then code-book lookups against a clock, then full-length timed rounds until you hold 85% or better.
Is there demand for plumbers in Portland?
Yes — 1,000+ open positions with +6% projected growth. Portland's heavy rainfall and aging Victorian-era plumbing create consistent repair and upgrade demand.
Do these practice questions copy the real Oregon exam?
No. Every question is original CraftPATH material written against published exam outlines and the code books Oregon has adopted. The format matches the real test, the content does not reproduce licensed exam material.
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