N.Y. Comp. Codes R. & Regs. tit. 12 § 23-5.1 : DEPARTMENT OF LABOR — Industrial Board Of Appeals — The Industrial Code — Protection In Construction, Demolition And Excavation Operations —5 - Scaffolding —5.1 - General provisions for all scaffolds

(a) Scope of this Subpart. The provisions of this Subpart pertaining to all scaffolds used in construction and demolition operations shall not be construed or applied in contravention of the special provisions pertaining to specific types of scaffolds hereinafter set forth.
(b) Scaffold footing or anchorage. The footing or anchorage for every scaffold erected on or supported by the ground, grade or equivalent surface shall be sound, rigid, capable of supporting the maximum load intended to be imposed thereon without settling or deformation and shall be secure against movement in any direction. Unstable supports, such as barrels, boxes, loose brick or loose stone, shall not be used.
(c) Scaffold structure.
(1) Except where otherwise specifically provided in this Subpart, all scaffolding shall be so constructed as to bear four times the maximum weight required to be dependent therefrom or placed thereon when in use. (See Labor Law, §240, subdivision 3.) Such maximum weight shall be construed to mean the sum of both dead and live loads.

Exception:Paragraph (1) above does not apply to scaffold suspension ropes. (See section 23-5.19 of this Subpart.)

(2) Every scaffold shall be provided with adequate horizontal and diagonal bracing to prevent any lateral movement.
(d) Scaffold loading.
(1) Light duty scaffolds shall not be loaded with live loads in excess of 25 pounds per square foot.
(2) Medium duty scaffolds shall not be loaded with live loads in excess of 50 pounds per square foot.
(3) Heavy duty scaffolds shall not be loaded with live loads in excess of 75 pounds per square foot.
(4) No scaffold shall be loaded in excess of the maximum load for which it is intended.
(e) Scaffold planking.
(1) Except on needle beam and pole scaffolds, scaffold planks shall extend not less than six inches beyond any support nor more than 18 inches beyond any end support. Such six inch minimum requirement shall not apply when such planks are securely fastened in place. Scaffold planks shall be laid tight and inclined planking shall be securely fastened in place.
(2) The maximum permissible live load for two-inch full size planking shall be as follows:
(i) Heavy duty scaffolds--75 pounds per square foot for spans up to and including six feet.
(ii) Medium duty scaffolds--50 pounds per square foot for spans over six feet and up to and including eight feet.
(iii) Light duty scaffolds--25 pounds per square foot for spans over eight feet and up to and including 10 feet.
(3) The maximum permissible live load for two-inch nominal thickness planking shall be as follows:
(i) Light duty scaffolds--25 pounds per square foot for spans over six feet and up to and including eight feet.
(ii) Medium duty scaffolds--50 pounds per square foot for spans up to and including six feet.
(iii) Heavy duty scaffolds--two-inch nominal thickness planking shall not be used for heavy duty scaffolds.
(4) The maximum permissible live load for one and one-quarter inch full size planking shall be 50 pounds per square foot for spans up to and including four feet.
(5) The minimum width of every planked scaffold platform shall be 18 inches except for the following:
(i) Bench type scaffolds where the working platforms are not more than 24 inches above the floor or other supporting surface shall be not less than nine inches in width.
(ii) Trestle and extension trestle ladder scaffold platforms shall have widths equal to the distances between the side rails of the ladders, but in no case shall such platforms be less than 12 inches in width.
(f) Scaffold maintenance and repair. Every scaffold shall be maintained in good repair and every defect, unsafe condition or noncompliance with this Part (rule) shall be immediately corrected before further use of such scaffold.
(g) Scaffold lumber. All lumber used in the construction of scaffolds and scaffold platforms shall be stress-grade, having a minimum unit stress "f" of 1500 psi. The use of scaffold lumber shall be in conformance with the grade classification, i.e. lumber graded for use as posts or columns shall not be used where beams or joists are required. All lumber subjected to stress shall be sound, straight grained, free from shakes, large, loose or dead knots or checks or from any other defects which may impair its strength or durability.
(h) Scaffold erection and removal. Every scaffold shall be erected and removed under the supervision of a designated person.
(i) Overhead protection. Overhead protection when required for any scaffold shall consist of planking not less than two inches thick full size, exterior grade plywood not less than three-quarters inch thick or material of equivalent strength. Such planks used for overhead protection shall be laid tight, shall extend the full length and width of the working platform. Such overhead protection shall be located not more than 10 feet above the surface of the working platform. Such overhead protection shall not be used to support any person, material, tools or equipment.
(j) Safety railings.
(1) The open sides of all scaffold platforms, except those platforms listed in the exception below, shall be provided with safety railings constructed and installed in compliance with this Part (rule).

Exceptions:Any scaffold platform with an elevation of not more than seven feet; the platforms of needle beam scaffolds; floats and rivet heater platforms in use by structural ironworkers; ladder jack scaffold platforms; and trestle and extension trestle ladder scaffold platforms.

(2) All scaffolds under which any person is likely to work or pass shall be provided with a wire mesh screen of not less than No. 18 U.S. gage steel with openings that will reject a one- inch diameter ball. Such wire mesh screen shall be installed between the toeboard and the top guard rail on both ends and on the outboard side of the scaffold platform.
(3) Any end or side of any scaffold platform that is located within six feet horizontally of an unenclosed side of a material hoist tower, construction elevator or similar moving equipment shall be effectively screened to a height of at least six feet above the scaffold platform. Such screen shall be constructed of wire mesh of not less than No. 18 U.S. gage steel with openings that will reject a one-inch diameter ball.
(k) Splices. Horizontal load-bearing members of any scaffold shall not be spliced between points of support.

N.Y. Comp. Codes R. & Regs. Tit. 12 § 23-5.1