Safety guides and audits to make your job as a safety professional easier

Structural Stability

The Work We Do: Ironworkers
(Click to play video)

Structural stability must be maintained at all times during the steel erection process.

Structural Steel Assembly

Since structural collapse is second only to falls as a cause of fatalities in this industry, stability is essential to the successful erection of any steel structure, including single-story, multi-story, and bridges. This section of the standard outlines the work practices that will prevent collapse due to lack of stability. In addition, it addresses slipping and tripping hazards and certain kinds of fall hazards encountered when working on steel structures.

Case Study

A crew of steelworkers was connecting a steel beam to a steel column on the seventh level of an airport structure. The base of the column was secured to a sheer concrete wall by temporary welds to an embedded steel plate.

When the crew encountered a problem connecting the beam to the column, a decision was made to pull the top of the column one inch to the north to facilitate the connection. The pull was performed by tensioning a guy wire, using a come-along, applying a fork at the column being connected, and using a sleeper. One worker was seated on the beam that was being connected, while another was standing at the base of the column, atop the concrete wall.

When the force of the tensioning caused the temporary welds at the column base to fracture, the column collapsed, and the two workers fell to their death.

Multi-Story Structures

Safety Nets Under the Golden Gate Bridge
(Click to play video)

Rules for steel erection safety for multi-level structures can be found in OSHA Standard 1926.754(b).

Permanent floors: Permanent floors must be installed as the erection of structural members progresses, with no more than eight stories between the erection floor and the upper-most permanent floor.

Unfinished bolting or welding: Unfinished bolting or welding above the foundation (or the uppermost secured floor) is not permitted to exceed the lesser of:

  • four floors
  • 48 feet (14.6 m)

Exceptions are allowed where structural integrity is accounted for in the design.

Safety Nets and Floors: Safety nets or a fully planked or decked floor must be maintained directly under any erection work being performed, within the lesser of:

  • two stories
  • 30 feet (9.1 m)

Walking/Working Surfaces

Tripping hazards: To prevent tripping hazards, do not attach the components listed below if they project from the top flanges of beams, joists, or beam attachments until after the metal decking, or other walking/working surface, has been installed.

  • shear connectors (such as headed steel studs, steel bars, or steel lugs)
  • reinforcing bars
  • deformed anchors
  • threaded studs, unless they are factory installed and all workers, including connectors and deckers, use fall protection at all times

Shear Connectors

sheer connector

When shear connectors are used in the construction of composite floors, roofs and bridge decks, they must be laid out and installed after the metal decking has been installed. The metal decking will then serve as a working platform.

Shear connectors may not be installed from within a controlled decking zone (CDZ).

Coated Surfaces

Workers are not be permitted to walk the top surface of any structural steel member installed after July 18, 2006 that has been coated with paint or similar material, unless all of the following are met:

  • The coating has achieved a minimum average slip resistance of .50 in laboratory tests.
  • The tests were based on the appropriate ASTM standard test method and conducted by a qualified laboratory.
  • Documentation of the test results is available at the site and to the steel erector.
plumbing up

Plumbing-Up

It’s important to make sure the structure being erected is “plumb” or exactly vertical. The process of lining up the building elements in a precise vertical direction is called “plumbing up.”

  • When a competent person deems it necessary, plumbing-up equipment must be installed during the steel erection process to ensure the stability of the structure.
  • When plumbing-up equipment is used, it must be in place and properly installed before the structure is loaded with construction material such as loads of joists, bundles of decking, or bundles of bridging.
  • Plumbing-up equipment may be removed only with the approval of a competent person.

Metal Decking

Hoisting, Landing and Placing Metal Deck Bundles

Follow these requirements when hoisting, landing, and placing metal decking bundles:

  • Bundle packaging and strapping may not be used for hoisting unless specifically designed for that purpose.
  • If loose items such as dunnage, flashing, or other materials are placed on top of metal decking bundles intended to be hoisted, they must be secured to the bundles.
  • When bundles of metal decking are landed on joists, all bridging must be installed and anchored, and all joist-bearing ends attached. (See Open web steel joists in Module 5 for exceptions.)
  • Metal decking bundles must be landed on framing members so that enough support is provided to allow the bundles to be unbanded without dislodging the bundles from the supports.
  • At the end of the shift or when environmental or jobsite conditions require, metal decking must be secured against displacement.

Roof and Floor Holes and Openings

Metal decking on roof and floor holes and openings must be installed as follows:

  • Framed metal deck openings must have structural members turned down to allow continuous deck installation, except where prevented by structural design constraints or constructability.
  • Openings such as roof and floor holes must be decked over.
  • Where large size, configuration, or other structural constraints do not allow openings to be decked over (e.g. elevator shafts, stair wells, etc.), employees must be protected in accordance with the fall protection provisions of this standard.

When metal decking holes and openings are cut, they must:

  • Immediately and permanently be filled with the intended equipment or structure.
  • Immediately be covered.

Covering Roof and Floor Openings

hole cover
Covers for roofs and floor opening must be capable of supporting twice the weight of the employees, equipment, and materials.
(Click to enlarge)

Covers for roof and floor openings must be capable of supporting, without failure, twice the weight of the employees, equipment, and materials that may be imposed on them at any one time.

All covers must be:

  • Secured when installed to prevent accidental displacement by the wind, equipment or employees.
  • Painted with high-visibility paint, or
  • Marked with the word "HOLE" or "COVER" to provide warning of the hazard.

Installed smoke dome or skylight fixtures are not considered covers, unless they meet the appropriate strength requirements.

Where planks or metal decking around columns do not fit tightly, wire mesh, exterior plywood, or equivalent material must be installed, and must be of sufficient strength to:

  • provide fall protection for personnel
  • prevent objects from falling through

Installation of Metal Decking

  • Metal decking must be laid tightly and immediately secured to prevent accidental movement or displacement.
  • Structural members must fully support metal decking panels during initial placement.

Derrick Floors

  • To support the intended floor loading, a derrick floor must be fully decked and/or planked, and the steel member connections completed.
  • Temporary loads placed on a derrick floor must be distributed over the underlying support members so as to prevent local overloading of the deck material.

Instructions

Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. Structural collapse is second only to _____ as a cause of fatalities in the steel erection industry.

2. When erecting multi-level structures, how many stories are allowed between the floor being erected and the upper-most permanent floor?

3. The process of lining up the building elements in a precise vertical direction is called _____.

4. Bill, the worksite supervisor, discovers a floor hole on the 2nd story floor. What should he do?

5. What must be done to prevent accidental movement or displacement of metal decking?


Have a great day!

Important! You will receive an "error" message unless all questions are answered.