Section 408.10526. Outrigger's scaffolds.

(1) A thrustout for an outrigger scaffold shall be of timber 3 by 10 inches nominal, set on edge, or of structural steel of equal strength set with the web vertical. A thrustout shall extend outside the building not more than 6 feet, shall be spaced not no more than on 6 foot centers, and shall be fastened to prevent twisting or other movement. A thrustout shall be braced diagonally from the outside end to the building. The brace shall be not less than 25% longer than the extended length of the thrustout. The inboard end of outrigger beams, measured from the fulcrum point to the extreme point of support, shall be not less than 1 1/2 times the outboard end in length.

(2)    A suspended platform shall be formed by use of 2 by 6 inch nominal vertical hangers and 2 by 6 inch nominal bearers. A vertical hanger shall be braced to prevent side sway and be not more than 10 feet long. Additional support blocks shall be nailed to the vertical hangers above the thrustouts and below the bearers. The inboard ends of outrigger beams shall be securely supported, either by means of struts bearing against sills in contact with the overhead beams or ceiling, or by means of tension members secured to the floor joist underfoot, or by both if necessary. The inboard ends of outrigger beams shall be secured against tipping, and the entire supporting structure shall be securely braced in both directions to prevent any horizontal movement.

(3)     Planking for the platform shall abut edges tightly from end of thrustout to building or from  vertical   hanger  to  vertical  hanger,   and  shall  be  as  prescribed  in R 408.10512.

(4)     A standard barrier and toeboard shall be installed as prescribed in General Industry Safety Standard Part 2 "Floor and Wall Openings, Stairways, and Skylights," as referenced in R 408.10509.

(5)   A horse scaffold shall not be used with an outrigger's scaffold.

(6)    Outrigger scaffolds designed by a registered professional mechanical or civil engineer shall be constructed and erected in accordance with such design. A copy of the detailed drawings and specifications, showing the sizes and spacing of members, shall be kept on the job.    Where additional working levels are required to be supported by the

outrigger method, the plans and specifications of the outrigger and scaffolding structure shall be designed by a registered professional mechanical or civil engineer.

History: 1979 AC; 2008 AACS; 2016 MR 16, Eff. Aug. 18, 2016.