IPC - International Plumbing Code Sanitary Drainage Systems Questions and Answers

Question 1

According to the IPC, what is the minimum required slope for a 4-inch horizontal sanitary drainage 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 slope required is 1/8 inch per foot (1-percent slope).

Question 2

A plumber is installing a new building sewer. According to the IPC, a cleanout is required at intervals of not more than:

Accepted Answer

100 feet

Answer

IPC Section 708.3.2 states that building sewers shall be provided with cleanouts located not more than 100 feet apart. This allows for proper access for cleaning and maintenance of the sewer line.

Question 3

Which of the following fittings is generally prohibited for use in a sanitary drainage system to connect a horizontal drain to another horizontal drain?

Accepted Answer

Sanitary tee

Answer

According to IPC Section 706.3 and associated tables, a sanitary tee is restricted to connecting a horizontal drain to a vertical drain. Using it in a horizontal-to-horizontal application can impede flow and lead to stoppages.

Question 4

In a multistory building, a cleanout is required at the base of each waste or soil stack. The IPC requires the size of this cleanout for a 3-inch stack to be:

Accepted Answer

The same nominal size as the pipe it serves

Answer

IPC Section 708.7 specifies that cleanouts shall be the same nominal size as the pipe they serve up to 4 inches. Therefore, a 3-inch stack requires a 3-inch cleanout.

Question 5

A horizontal wet vent is being installed to serve two bathroom groups on the same floor. According to the IPC, which of the following statements is correct?

Accepted Answer

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

Answer

IPC Section 912.1 requires that each fixture drain connecting to a horizontal wet vent does so independently. This ensures that the discharge from one fixture does not interfere with the venting of another.

IPC - International Plumbing Code Practice Test

IPC - International Plumbing Code Practice Test

IPC - International Plumbing Code Sanitary Drainage Systems Questions and Answers