2013 California Standards for Accessible Design Pocket Guide

1131A.2 Changes greater than ½ inch.  Changes in level greater than ½ inch (12.7 mm) shall be made by means of a sloped surface not greater than 1 unit vertical in 20 units horizontal (5-percent slope), or a ramp, elevator or platform (wheelchair) lift. See Section 1122A for ramps and Section 1124A.11 for platform (wheelchair) lifts.