surface level changes

303.2-4 – Level Changes

303.2 Vertical.
Changes in level of 6.4 mm (1/4″) high maximum shall be permitted to be vertical.

303.3 Beveled.
Changes in level between 6.4 mm (1/4″) high minimum and 13 mm (1/2″) high maximum shall be beveled with a slope not steeper than 1:2.

303.4 Ramps.
Changes in level greater than 13 mm (1/2″) high shall be ramped, and shall comply with 405 or 406.