Free Practice Questions for IA Plumber

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Exam Review

Key Facts: IA Plumber Exam

70%

Passing Score

Iowa Plumbing and Mechanical Systems Board

100

Questions

3 hours limit

$25 + $50-240

Exam Fee

PSI

UPC

Code Base

Iowa adoption

Iowa's journeyman plumber exam is based on the UPC (Iowa State Plumbing Code) and administered by PSI. Iowa uses the UPC rather than the IPC. The Iowa State Plumbing Code includes amendments for cold climate conditions and rural water/sewer systems. The exam requires 70% to pass and tests drainage, water supply, venting, gas piping, and fixture knowledge.

Sample IA Plumber Practice Questions

Try these sample questions to review concepts for the IA Plumber exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 318+ question experience with AI tutoring.

1Under the 2024 UPC as adopted in Iowa, how is the minimum building sewer size determined?

A.It is always 2 inches

B.It is always 3 inches

C.It is based on drainage load and cannot be smaller than the building drain

D.It is always 6 inches

Explanation: UPC 717.1 sizes the building sewer from its drainage load and does not permit it to be smaller than the building drain.

2What slope applies to a 4-inch horizontal drainage pipe under the 2024 UPC?

A.1/16 inch per foot

B.1/8 inch per foot automatically

C.1/4 inch per foot, unless the AHJ approves 1/8 inch where 1/4 inch is impractical

D.No minimum slope

Explanation: UPC 708.1 sets 1/4 inch per foot generally. A 4-inch or larger pipe may use 1/8 inch only where 1/4 inch is impractical and the AHJ approves.

3What DFU value does the 2024 UPC assign to a private 1.6-gpf water closet?

A.2

B.3

C.4

D.6

Explanation: UPC Table 702.1 assigns 3 DFU to this private water closet.

4Per the Iowa State Plumbing Code (UPC), what is the maximum distance between cleanouts on a horizontal drainage pipe?

A.50 feet

B.75 feet

C.100 feet

D.150 feet

Explanation: Per UPC cleanout requirements, cleanouts must be installed at intervals not exceeding 100 feet on horizontal drainage lines. Proper cleanout spacing ensures the entire system can be maintained and cleared of blockages.

5Which containment protection does Iowa require for a high-hazard public water service?

A.Double-check valve only

B.Pressure vacuum breaker only

C.An air gap or approved reduced-pressure-principle assembly

D.Atmospheric vacuum breaker only

Explanation: Iowa 481—425.5(4) requires a high-hazard water service to be protected by an air gap or an approved reduced-pressure-principle backflow-prevention assembly.

6What is the maximum flow rate for an individual showerhead under the 2024 UPC?

A.1.0 gpm at 60 psi

B.1.5 gpm at 60 psi

C.2.5 gpm at 80 psi

D.4.0 gpm at 80 psi

Explanation: UPC 408.3 limits an individual showerhead to 2.5 gpm at 80 psi.

7Which protection does the 2024 UPC require against excessive water-heater temperature?

A.Only the normal thermostat

B.A listed separate overtemperature device or listed combination T&P relief valve

C.A manual drain valve

D.A building pressure regulator

Explanation: UPC 504.4 through 504.6 require approved pressure and overtemperature protection; normal operating controls alone are insufficient. The protection may use listed separate devices or an approved listed combination T&P relief valve.

8Per the Iowa State Plumbing Code (UPC), what is the minimum trap seal depth for a standard plumbing fixture?

A.1 inch

B.2 inches

C.3 inches

D.4 inches

Explanation: Per UPC trap requirements, the minimum trap seal depth is 2 inches and the maximum is 4 inches. The water seal prevents sewer gases from entering the building through fixture drains.

9What is the general minimum vent size under the 2024 UPC?

A.1 inch

B.1-1/4 inches and at least half the drain diameter

C.1-1/2 inches in every case

D.2 inches in every case

Explanation: UPC 904.1 requires at least 1-1/4 inches and at least half the diameter of the drain served.

10Per the Iowa State Plumbing Code (UPC), what is the maximum static water pressure in a building distribution system?

A.60 psi

B.80 psi

C.100 psi

D.125 psi

Explanation: Per UPC water pressure requirements, water pressure shall not exceed 80 psi static. Where pressures exceed 80 psi, a pressure-reducing valve must be installed to prevent fixture damage and pipe noise.

About the IA Plumber Exam

Iowa journeyman plumber exam administered by PSI under the Plumbing and Mechanical Systems Board. Based on the Uniform Plumbing Code (UPC) with Iowa amendments. Tests drainage, water supply, venting, gas piping, and Iowa-specific requirements.

Exam sponsor: Iowa Plumbing and Mechanical Systems Board. The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Questions

100 questions

Time Limit

3 hours

Passing Score

70%

Exam / Certification Fees

$25 + $50-240

Exam sponsor website

Reported exam pass rate: ~50-60%. This describes exam candidates, not OpenExamPrep users or results from using our resources. Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Official sources

Iowa Plumbing and Mechanical Systems Board: official exam information

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

25%

Drainage & Waste Systems

Drain sizing, DFU calculations, slope requirements, cleanouts per UPC

20%

Water Supply & Distribution

Pipe sizing, backflow prevention, water heaters, pressure regulation per UPC

20%

Venting Systems

Vent sizing, wet venting, AAVs, vent termination, circuit venting per UPC

15%

Gas Piping

Gas pipe sizing, appliance venting, pressure testing, BTU calculations per IFGC

20%

Fixtures, Materials & Iowa Code

Fixture installation, materials, joints, permits, inspections, and Iowa-specific requirements

Preparing for the IA Plumber Exam

What You Need to Know

Passing score: 70%
Exam length: 100 questions
Time limit: 3 hours
Exam / certification fees: $25 + $50-240 Official sources

Using Our Practice Resources

Work through all 318 available questions
Review every answer and explanation
Track weak areas and revisit them
Use our AI tutor for tough concepts

IA Plumber: Suggested Study Strategy

1Master UPC drainage fixture unit (DFU) values and pipe sizing tables

2Study backflow prevention device selection and cross-connection control

3Memorize minimum pipe sizes, slopes, and clearances for common fixtures

4Practice gas pipe sizing calculations using IFGC tables

5Understand wet venting and circuit venting provisions in the UPC

6Learn Iowa-specific permit and inspection requirements

Frequently Asked Questions

What code does Iowa use for the plumber exam?

Iowa uses the UPC (Iowa State Plumbing Code). The exam covers drainage, venting, water supply, gas piping, and fixture requirements as adopted by the state.

Who administers the Iowa plumber exam?

The exam is administered by PSI under the Iowa Plumbing and Mechanical Systems Board.

How many questions are on the Iowa plumber exam?

The Iowa plumber exam has approximately 100 questions with a 3 hours time limit. A score of 70% is required to pass.

Is the IA plumber exam open book?

Most PSI-administered plumber exams allow a bound copy of the adopted code. Check with the Iowa Plumbing and Mechanical Systems Board for approved reference materials.

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