Table § 18-29-608.15.1

Minimum Required Air Gaps

Fixture	Minimum Air Gap
Fixture	Away from a wall a (inches)	Close to a wall (inches)
Lavatories and other fixtures with effective opening not greater than 1/2 inch in diameter	1	1 1/2
Sink, laundry trays, gooseneck back faucets and other fixtures with effective openings not greater than 3/4 inch in diameter	1 1/2	2 1/2
Over-rim bath fillers and other fixtures with effective openings not greater than 1 inch in diameter	2	3
Drinking water fountains, single orifice not greater than 7/16 inch in diameter or multiple orifices with a total area of 0.150 square inch (area of circle 7/16 inch in diameter).	1	1 1/2
Effective openings greater than 1 inch.	Two times the diameter of the effective opening.	Three times the diameter of the effective opening.

For SI: 1 inch = 25.4 mm.

a Applicable where walls or obstructions are spaced from the nearest inside edge of the spout opening a distance greater than three times the diameter of the effective opening for a single wall, or a distance greater than four times the diameter of the effective opening for two intersecting walls.