R311.7.5

Section R311.7.5 is titled 'Stair treads and risers' and covers the requirements for steps in a stairway. This section only references subsections for technical details, but does clarify that any dimensions shall be taken prior to carpets, rugs, or runners being placed on the treads and/or risers.

The model shows the treads and risers of a stairway and spiral stairway. Note that the term 'tread' is not found in the definitions of chapter 2, but 'riser (stair)' is; being defined as a vertical 'component' of a step or stair. In some cases, this 'component' may be just empty space, as shown on the spiral stairway.