R311.7.7

Section R311.7.7 is titled 'Stairway walking surface' and covers the requirements for the levelness of stairway treads and landings with the amount of slope being established. The purpose of this section is to allow for a slight amount of slope so water will drain, yet not allowing too much slope that would create a trip/slip and fall hazard.

The model shows two partial stairways side-by-side with the front stairway having fixed level treads and landing, and the rear stairway with treads and landing that are adjusting from level to the maximum amount of slope allowed per this section. It is a very subtle change best observed from the side, eye level with the treads in a horizontal position. Note that the '2-percent slope' in parentheses, is a slightly rounded down conversion from the specifically required rise and run of 1 unit in 48 units. (48 'inches' is an editorial error)