PC PC Plumbing Codes & Regulations 1 — Questions and Answers
Question 1: Which model plumbing code is most widely adopted by US states and municipalities?
- Uniform Plumbing Code (UPC)
- International Plumbing Code (IPC) (Correct answer)
- National Plumbing Code (NPC)
- Standard Plumbing Code (SPC)
Correct answer: International Plumbing Code (IPC)
The International Plumbing Code (IPC), published by the ICC, is the most widely adopted model plumbing code across US states and municipalities.
Question 2: Under the IPC, what is the minimum trap arm length allowed for a 1.5-inch drain from a lavatory?
- 1.5 inches
- 2 inches
- No minimum is specified (Correct answer)
- 3 inches
Correct answer: No minimum is specified
The IPC does not specify a minimum trap arm length, but does require that the trap arm slope toward the drain and not exceed the maximum allowed distance.
Question 3: A plumber installs a new water closet in a commercial building. According to the IPC, what is the minimum required flush volume for a tank-type water closet?
- 1.0 gpf
- 1.6 gpf (Correct answer)
- 2.0 gpf
- 3.5 gpf
Correct answer: 1.6 gpf
The IPC requires tank-type water closets to use a maximum of 1.6 gallons per flush (gpf), which is also the federal maximum established by the Energy Policy Act.
Question 4: According to plumbing code, a vent pipe that terminates through the roof must extend at least how far above the roof surface in a climate with fewer than 30 days below 0°F?
- 3 inches
- 6 inches (Correct answer)
- 12 inches
- 24 inches
Correct answer: 6 inches
In areas with fewer than 30 days per year below 0°F, vent pipes must extend at least 6 inches above the roof surface to prevent frost closure and allow proper air flow.
Question 5: Which of the following fixtures is NOT required to be individually vented under standard IPC provisions?
- Floor drain (Correct answer)
- Water closet
- Bathtub
- Kitchen sink
Correct answer: Floor drain
Floor drains may be connected to a common vent system and are not individually required to be vented in most IPC provisions.
Question 6: When a plumbing permit is required by code, who is typically authorized to sign and pull the permit?
- The building owner
- The general contractor
- A licensed plumber or plumbing contractor (Correct answer)
- The local building inspector
Correct answer: A licensed plumber or plumbing contractor
Plumbing permits must typically be obtained by a licensed plumber or plumbing contractor who is legally responsible for the work.
PC PC Plumbing Codes & Regulations 1
Which model plumbing code is most widely adopted by US states and municipalities?