The standard requires guardrail systems and components to be designed and built to meet the requirements of § 1926.502 (b) (3), (4), and (5). This appendix serves as a non-mandatory guideline to assist employers in complying with these requirements. An employer may use these guidelines as a starting point for designing guardrail systems. However, the guidelines do not provide all the information necessary to build a complete system, and the employer is still responsible for designing and assembling these components in such a way that the completed system will meet the requirements of § 1926.502(b) (3), (4), and (5). Components for which no specific guidelines are given in this appendix (e.g., joints, base connections, components made with other materials, and components with other dimensions) must also be designed and constructed in such a way that the completed system meets the requirements of § 1926.502.

(1) For wood railings: Wood components shall be minimum 1500 lb-ft/in 2 fiber (stress grade) construction grade lumber; the posts shall be at least 2-inch by 4-inch (5 cm × 10 cm) lumber spaced not more than 8 feet (2.4 m) apart on centers; the top rail shall be at least 2-inch by 4-inch (5 cm × 10 cm) lumber, the intermediate rail shall be at least 1-inch by 6-inch (2.5 cm × 15 cm) lumber. All lumber dimensions are nominal sizes as provided by the American Softwood Lumber Standards, dated January 1970.

(2) For pipe railings: posts, top rails, and intermediate railings shall be at least one and one-half inches nominal diameter (schedule 40 pipe) with posts spaced not more than 8 feet (2.4 m) apart on centers.

(3) For structural steel railings: posts, top rails, and intermediate rails shall be at least 2-inch by 2-inch (5 cm × 10 cm) by 3/8-inch (1.1 cm) angles, with posts spaced not more than 8 feet (2.4 m) apart on centers.