Intermediate step design and construction is another subject that needs to be considered carefully to insure patron safety. When we draw a layout we try to fill the row from side-to-side to eliminate hazardous gaps so it's critical to design intermediate steps that provide enough space to fit the required chair sizes and quantity in the row. For straight layouts we can often provide different chair sizes to fill the space between steps as shown here.
This issue of hazardous gaps with intermediate steps is most often seen when treads and risers are constructed on a radius. A common mistake occurs when the intermediate steps are constructed parallel to a wall or some other architectural element. Chair standards need to be installed perpendicular to the riser face and dangerous gaps are created when steps do not match the angle of the chair standards. Here is a simple example: