Table § 18-29-709.1


Drainage Fixture Units for Fixtures and Groups

Fixture Type

Drainage Fixture Unit Value as Load Factors

Minimum Size of Trap (inches)

Automatic clothes washers, commercial a

3

2

Automatic clothes washers, residential

2

2

Bathroom group consisting of water closet, lavatory, bidet and bathtub or shower

6

Bathroom b (with or without overhead shower or whirlpool attachments)

2

1 1/2

Bidet

2

1 1/4

Combination sink and tray

2

1 1/2

Dental lavatory

1

1 1/4

Dental unit or cuspidor

1

1 1/4

Dishwashing machine, c domestic

2

1 1/2

Drinking fountains

1/2

1 1/4

Emergency floor drain

0

2

Floor drains

2

2

Kitchen sink, domestic

2

1 1/2

Kitchen sink, domestic with food waste grinder and/or dishwasher

2

1 1/2

Laundry tray (1 or 2 compartments)

2

1 1/2

Lavatory

1

1 1/4

Shower compartment, domestic

2

2

Sink

2

1 1/2

Urinal

4

Footnote d

Urinal, 1 gallon per flush or less

2 e

Footnote d

Wash sink, (circular or multiple) each set of faucets

2

1 1/2

Water closet, flushometer tank, public or private

4 e

Footnote d

Water closet private installation

4

Footnote d

Water closet public installation

6

Footnote d

For SI: 1 inch = 25.4 mm, 1 gallon = 3.785L.

a) For traps larger than 3 inches, use Table 709.2.

b) A showerhead over a bathtub or whirlpool bathtub attachments does not increase the drainage fixture unit value.

c) See Section 709.2 for methods of computing unit value of fixtures not listed in Table 709.1 or for rating of devices with intermittent flows.

d) Trap size shall be consistent with the fixture outlet size.

e) For the purpose of computing loads on building drains and sewers, water closets or urinals shall not be rated at a lower drainage fixture unit unless the lower values are confirmed by testing.