R312.1.1

Section R312.1.1 is titled 'Where required' and covers the requirements for when barriers at the edges of raised walking surfaces must be installed. Places guards are required, maximum elevation difference allowed without a guard, method for taking elevation change measurements, and exclusion of insect screen being used as a guard, are established. The purpose of this section is to reduce fall hazards.

The model shows a raised platform above sloped ground, with a stairway connecting from the ground to the platform. The guards are installed on the stairs and platform where the elevation difference exceeds the dimension limitation allowed without a guard. Notice that the ground slopes away from one side of the stairway, and that a lower level area adjacent to the level of the treads is highlighted; all of this area must be checked for the vertical measurement compliance - the measurement cannot only be taken straight down at the edge of the treads. This is why the guard extends farther down on one side of the stairway than the other. (Note - the model depicts this requirement only at one point on the side of the stairway [where it may not be visually obvious], as an example, but it applies to any and all elevated walking surfaces).