Tiered floors in skeleton steel construction

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

September 22, 1977

MEMORANDUM FOR: ROBERT A. WENDELL
Acting Regional Administrator, Atlanta

ATTENTION: CARLYLE F. BUNN
Acting ARA for the [Directorate of Science, Technology, and Medicine]

THROUGH: DONALD E. MACKENZIE
Acting Field Coordinator

FROM: RICHARD P. WILSON
Deputy Director, [Directorate of Cooperative and State Programs]

SUBJECT: 1926.750 Flooring Requirements in Skeleton Steel Construction in Tiered Buildings

This is in response to a memorandum, from your office, August 5, 1977, subject as above.
Depending on the functional requirements of the building itself and the materials used in constructing its roof, floors and walls, one or more methods of framing may be used in a single structure.
In most types of buildings, floor and roof systems are so intimately related that the two are considered together in the development of a design. Both are important, but floors are the determining factor in defining "tiered". Structural designs for mezzanines, service levels and other partial floor levels are also "tiered" when one forms a level above the other. Thus, the word "tier", as used in 29 CFR Part 1926, Subpart R, relates to floor design.
For other than "tiered" design, [illegible in source] designs not adaptable to temporary floors, to install and maintain safety nets whenever the potential fall distance exceeds two stories or 25 feet.
Since one or more methods of framing may be used in a single structure, the safety net and/or flooring requirements may apply in the one structure for the respective need.
[Correction 6/20/2005. See OSHA Directive CPL 02-01-034 "Inspection policy and procedures for OSHA's steel erection standards for construction" published on 3/22/2002 for the current policy on OSHA's steel erection standards (1926 Subpart R) for construction.]