Free IPC Sanitary Drainage Systems Questions and Answers

Question 1

A plumber is installing a horizontal sanitary drainage line for a series of floor drains in a commercial kitchen. The pipe has a diameter of 4 inches. According to IPC Table 704.1, what is the minimum required slope for this pipe?

Accepted Answer

1/8 inch per foot

Answer

IPC Table 704.1 specifies the minimum slope for horizontal drainage piping. For pipes with a diameter of 3 to 6 inches, the minimum required slope is 1/8 inch per foot.

Question 2

A wet vent is being installed to serve two full bathroom groups on the same floor. Which of the following is a requirement for this type of installation under the IPC?

Accepted Answer

Each fixture drain must connect independently to the horizontal wet vent.

Answer

According to IPC Section 912.1, any combination of fixtures within two bathroom groups on the same floor level can be vented by a horizontal wet vent. A key requirement is that each wet-vented fixture drain must connect independently to the horizontal wet vent to ensure proper function.

Question 3

When transitioning a sanitary drainage line from horizontal to vertical, which of the following fittings is generally prohibited by the IPC for this specific change in direction?

Accepted Answer

Sanitary tee used on its back

Answer

A sanitary tee is designed for horizontal-to-vertical transitions (e.g., a fixture arm entering a vertical stack). Using it on its back to change flow from a horizontal drain to a vertical drain is prohibited because its short-radius pattern can cause solids to accumulate and lead to blockages.

Question 4

A building's sanitary drainage system is located in a basement, and the fixtures are below the level of the public sewer. What does the IPC require for discharging the waste?

Accepted Answer

Discharge into a tightly covered and vented sump that is automatically pumped to the building drain.

Answer

According to IPC Section 712, drainage piping from fixtures located below the level of the public sewer cannot discharge by gravity. The code mandates that such drainage must be collected in a tightly covered and vented sump and then automatically lifted and discharged into the building's gravity drainage system by a sewage pump or ejector.

Question 5

According to the IPC, what is the maximum required spacing between cleanouts on a horizontal sanitary drainage line that is 6 inches in diameter?

Accepted Answer

100 feet

Answer

IPC Section 708.3.1 states that all horizontal drains within buildings shall be provided with cleanouts located not more than 100 feet apart. This requirement applies to pipes of various sizes, including 6-inch diameter lines.

IPC - International Plumbing Code Practice Test

IPC - International Plumbing Code Practice Test

Free IPC Sanitary Drainage Systems Questions and Answers