Master Plumber Exam Plumbing Codes and Standards 4 — Questions and Answers
Question 1: Under the IPC, which of the following water heater installations requires a seismic strap in Seismic Design Category C or higher?
- All water heaters regardless of fuel type (Correct answer)
- Only gas-fired water heaters
- Only electric water heaters over 40 gallons
- Only water heaters over 30 inches tall
Correct answer: All water heaters regardless of fuel type
The IPC requires seismic strapping for all water heaters in Seismic Design Categories C, D, E, and F, regardless of fuel type or size.
Question 2: Per the IPC, what is the maximum water pressure allowed at any plumbing fixture in a building?
- 60 psi
- 80 psi (Correct answer)
- 100 psi
- 125 psi
Correct answer: 80 psi
The IPC limits the maximum static pressure at any fixture to 80 psi; if street pressure exceeds this, a pressure-reducing valve must be installed.
Question 3: According to the IPC, what is the minimum flow rate required at a lavatory faucet for public use?
- 0.5 gpm
- 1.0 gpm (Correct answer)
- 1.8 gpm
- 2.2 gpm
Correct answer: 1.0 gpm
The IPC requires public lavatory faucets to deliver a minimum flow rate of 0.5 gpm but caps them at 0.5 gpm per the WaterSense standard; however the minimum for general lavatory supply is 1.0 gpm.
Question 4: Under the IPC, which type of pipe joint is prohibited in concealed locations for water supply piping?
- Soldered joints
- Compression fittings
- Push-fit fittings
- Flared joints (Correct answer)
Correct answer: Flared joints
Flared joints are not approved for use in concealed locations under the IPC because they can loosen over time and require access for inspection.
Question 5: Per the IPC, what is the minimum number of plumbing fixtures required for a single-occupant toilet room?
- One water closet only
- One water closet and one lavatory (Correct answer)
- One water closet, one lavatory, and one floor drain
- One water closet, one urinal, and one lavatory
Correct answer: One water closet and one lavatory
The IPC requires at least one water closet and one lavatory in a toilet room serving a single occupancy.
Question 6: Under the IPC, a building with an occupant load of 76–125 of each sex requires how many water closets for women?
- 2
- 3
- 4 (Correct answer)
- 5
Correct answer: 4
Per IPC Table 403.1, an assembly occupancy with 76–125 female occupants requires 4 water closets for women.
Question 7: Per the IPC, what is the minimum cleanout size required for a 6-inch building drain?
- 2 inches
- 3 inches
- 4 inches (Correct answer)
- 6 inches
Correct answer: 4 inches
The IPC requires cleanouts to be not less than 4 inches for building drains 6 inches and larger in diameter.
Master Plumber Exam Plumbing Codes and Standards 4
Under the IPC, which of the following water heater installations requires a seismic strap in Seismic Design Category C or higher?