(1) Except as provided in Sentences (2) and (3) and unless it can be shown that the platform does not present a hazard, a guard not less than 1 070 mm high shall be provided for a platform of a demountable stage where the difference in elevation between the platform and the adjacent surface is more than 1 500 mm.
(2) Sentence (1) need not apply at the edges of a platform of a demountable stage that face an audience.
(3) The height of guards for stairs shall be,
(a) not less than 920 mm measured vertically to the top of the guard from a line drawn through the outside edges of the stair nosings, and
(b) not less than 1 070 mm around landings.
(4) Guards shall be designed to withstand loads specified in Part 4.
(5) Required guards shall be provided with a top rail and one or more intermediate rails spaced such that openings through the guard are of a size that prevents the passage of a spherical object having a diameter of 535 mm.