Required guards shall not have openings from the walking surface to the required guard height that allow passage of a sphere 4 inches (102 mm) in diameter PHOTO 71.

Exceptions:

  1. The triangular openings at the open side of stair, formed by the riser, tread and bottom rail of a guard, shall not allow passage of a sphere 6 inches (153 mm) in diameter PHOTO 72.
  2. Guards on the open side of stairs shall not have openings that allow passage of a sphere 4⅜ inches (111 mm) in diameter PHOTO 72.