Concrete Reinforcement (Rebar) Impalement Hazards Expert Overview

The installation of reinforcing bars for concrete construction, or rebar, is a specialized construction activity that is inherently dangerous not only for the craftsmen engaged in the actual rebar installation but also to others in the vicinity of their work.

In this article, Civil Engineer & Construction Expert, Jeffrey Tedder, P.E., focuses on the dangers associated with impalement hazards present when the work in progress is not properly guarded.

Concrete Reinforcement 101

Concrete, when properly designed, mixed, installed, and cured, has excellent compressive strength but lacks the necessary tensile strength that most structures require. Steel, the most common reinforcement material in use, offers excellent strength in tension. Structural engineers incorporate steel reinforcement in their design of concrete structures to ensure that the structure can resist the various forces imposed on it.

Welded wire fabric or loose fiber may be appropriate for lighter duty applications such as sidewalks, driveways, and even building slabs. Heavier duty concrete pavements, foundations, beams, columns, and slabs, as well as masonry walls, require solid deformed steel bar reinforcement, or rebar. Rebar is fabricated in various sizes to meet the requirements of the structural design; the bar size designation refers to the nominal bar diameter in 1/8 of inch increments (i.e. a #4 bar = ½” diameter). 

Reinforced Concrete Construction

The typical construction of a concrete structure requires multiple concrete placements. Figure 1, for example, details 12 individual slab placements which combine to incorporate the full slab of the structure. Structural components are divided into individual pour placements to meet structural code requirements or for constructability.  

Where concrete and masonry walls and columns are constructed on top of concrete slabs and decks (mats), reinforcement dowel bars are installed integral in that applicable mat (Figure 2). Because it is impractical, in most instances, to place walls and columns monolithically with mats, the wall dowels are installed so wall/column steel can be continued after the completion of the mat pour placement. 

The reinforcement supplier is generally responsible for furnishing reinforcement drawings which the installer uses for installation and the supplier uses to fabricate the various rebar lengths and shapes that they will delver to the project site. Because of the physical demands and expertise required to install concrete reinforcement efficiently and effectively, the General Contractor will often elect to hire a specialized ironwork subcontractor, or “rodbuster” to complete this work. 

In most cases, the General Contractor will furnish the “permanent” materials such as the reinforcement itself, and the rodbuster will furnish the labor and “incidental or expendable” materials such as tie-wire and safety rebar caps. 

Rebar Impalement Hazard

The responsibility for the guarding of rebar impalement hazards should be defined in the subcontract agreement but is generally the responsibility of the rodbuster. The General Contractor, however, always maintains responsibility to ensure that the hazard is guarded against, even if the responsibility for installing impalement protection is assigned to the rodbuster.   

The exposed “tails” of the rebar protruding beyond the finished face of the concrete pour or at the leading edge of the unfinished work pose several hazards for workers. The edges of the mechanically cut bar are sharp enough to cut or scratch. More significant injuries can be sustained when an individual stumbles into or falls onto the unprotected end of an exposed bar. Exposed wall dowels, such as detailed in Figure 2, and tails located at the top of wall formwork, pose the most significant danger.

Under 29 CFR 1926.701(b), OSHA requires that 

“All protruding reinforcing steel, onto and into which employees could fall, shall be guarded to eliminate the hazard of impalement.” 

There are several types of commercially available products on the market that effectively guard against reinforcement impalement hazards. These products are readily available, inexpensive, easy to install, and can be re-used multiple times (see Figure 3).

Rebar Impalement Hazard Guarding Best Practices

The General Contractor, as the responsible authority on-site, must make sure that employees are protected from exposure to impalement hazards by installing conforming guarding. General best practices should include the following:

• Clearly delegate in subcontract agreements which party is responsible for the installation and maintenance of rebar impalement protection.
• Assure that OSHA-compliant caps are available onsite before starting rebar installation. Verify that the caps are appropriate for the size bar being used; most caps work on a range of rebar sizes.
• Inspect the worksite each day to ensure that rebar caps are in place.
• Perform periodic inspections to verify that the rebar caps used are undamaged. Even though the caps are reusable, the ribs located interior to the sleeve portion that fits over the bar can become damaged after multiple uses, especially if a cap has previously been installed on a larger diameter bar.
• Train employees to keep an eye out for missing caps and to report such findings to supervision for correction.
• Hold the responsible party accountable for assuring rebar protection is installed and maintained.

Rebar Injury Expert Witness Investigations

Construction worksite hazards can be controlled when all parties involved conduct their work in accordance with industry standards and established best practices. The Construction Safety experts at Robson Forensic have worked at every level within the industry, from bricklayer on residential projects to project manager on multi-prime worksites. Our experts have performed the work central to your case and can testify regarding the hazards, risks, and responsibilities in the construction industry.

For more information, submit an inquiry or call us at 800.813.6736.

Featured Expert

Jeffrey A. Tedder, P.E.

Civil Engineer & Construction Safety Expert

Jeffrey Tedder is a Civil Engineer with nearly 20 years of professional construction and engineering experience. His experience in complex, industrial construction where all trades are involved has… read more.