According to the Building Code, the maximum clearance between rails or ornamental pattern (balusters, (pickets) or the vertical members) on open guardrails or set of stairs shall be placed so that a _____ diameter sphere cannot pass through them.

According to the Building Code, the maximum clearance between rails or ornamental pattern (balusters, (pickets) or the vertical members) on open guardrails or set of stairs shall be placed so that a _____ diameter sphere cannot pass through them.