Each supporting bracket of a carpenters' portable bracket scaffold shall consist of a triangular portable frame constructed of wood not less than two inches by three inches in cross-section or shall be constructed of metal of equivalent strength. The members of such brackets shall be properly fitted and securely joined.

Each such bracket shall be attached to the wall of a building or other structure by means of a bolt not less than five-eighths inch in diameter. Such bolt shall extend through such wall and shall be secured to develop the required strength. The brackets shall be spaced not to exceed eight feet, center to center. Where the use of five-eighths inch diameter bolts for such installations is impractical, such brackets shall be secured by whaler cleats or metal ties equivalent in strength to five-eighths inch diameter bolts.

No more than two persons shall occupy any given 16 feet of a carpenters' portable bracket scaffold at any one time. The total weight of supplies, tools, materials or equipment placed on any such scaffold in addition to the occupants shall not exceed 100 pounds.

Where the working platform of any carpenters' portable bracket scaffold is elevated more than seven feet above the ground, grade, floor or equivalent surface, such platform shall be provided with a safety railing constructed and installed in compliance with this Part (rule).