Fixtures not listed in Table 18-29-709.1.
Municipal Code of Chicago § 18-29-709.2
in effect18-29-709.2 Fixtures not listed in Table 18-29-709.1.
Fixtures not listed in Table 18-29-709.1 shall have a drainage fixture unit load based on the outlet size of the fixture in accordance with Table 18-29-709.2. The minimum trap size for unlisted fixtures shall be the size of the drainage outlet but not less than 1 1/4 inches (32 mm).
Table 18-29-709.2
Drainage Fixture Units for Fixture Drains or Traps
Fixture Drain or Trap Size (inches) | Drainage Fixture Unit Value
1 1/4 | 1
1 1/2 | 2
2 | 3
2 1/2 | 4
3 | 5
4 | 6
For SI: 1 inch = 25.4 mm.
Source: City of Chicago, Municipal Code of Chicago (American Legal Publishing, codelibrary.amlegal.com)URL: https://codelibrary.amlegal.com/codes/chicago/latest/chicago_il/0-0-0-2692166Fetched: 10/24/2026