ADA Grab Bar Failures Expert Article

The failure of ADA-compliant grab bars can result in serious injury. This article provides a technical overview of grab bar failures from an engineering perspective, focusing on load requirements as well as the performance of the substrate and fasteners.

ADA Grab Bar Failure Expert Investigations

At Robson Forensic, our structural engineering experts are often retained to investigate grab bar failures across residential and commercial settings. Our investigations address the applicable standards of care, the load path from the user through the connection to the wall, and the factors that contributed to failure. The strength and anchorage requirements discussed in this article are also applicable to wall mounted sinks, toilets, shower seats, and other ADA bathroom fixtures.

The Americans with Disabilities Act (ADA) establishes performance criteria for grab bars and other accessibility features. The purpose of these fixtures is to provide support and stability to people as they move around or change positions, particularly in environments such as bathrooms.

Because grab bars are frequently relied upon under dynamic and emergency conditions, failure of any part of the grab bar can result in serious injury. 

Design Requirements

The International Building Code (IBC) and the ADA specify the minimum design requirements for grab bars. The IBC requires grab bars, shower seats, and accessible benches to resist a single concentrated load of 250 pounds applied in any direction and at any point on that fixture. 

This load requirement governs the design of the entire assembly — the bar, the mounting flanges, the fasteners, and the supporting substrate.

Grab bars are commonly manufactured and tested to meet the requirements of ASTM F446 and thus are not generally the portion of the assembly that fails during use. The most common mode of failure of a grab bar occurs at its connection to the wall. Grab bar connection failures often consist of fasteners pulling away from the wall or tearing through the substrate. 

Two common installation scenarios that produce this outcome are:

• Improper attachment of the grab bar to drywall only — the most common failure mode, discussed in detail below.
• Fasteners that are inappropriate for the anticipated loads or environmental conditions — including undersized screws, corroded fasteners, or inappropriate fastener selection.

Gypsum wallboard (drywall) alone is incapable of resisting the code mandated concentrated loads that a grab bar fixture may impose. Despite this, grab bars are frequently installed directly onto drywall using commercially available hollow-wall anchors, (toggle bolts, plastic expansion anchors, or self-drilling drywall anchors), without engagement of underlying wall framing, plywood backing, or blocking (wood framing between the wall studs, against the back face of the drywall). 

Testing of ADA Grab Bar Drywall Anchors 

Testing performed by Robson Forensic demonstrated that drywall anchors consistently fail prior to achieving the required resistance to allow the ADA fixture to safely resist the minimum code-mandated loads.

To demonstrate the performance of different anchor systems utilizing different fasteners, Robson Forensic conducted failure testing of ADA grab handles comparing the performance of a grab bar installed directly into wood backing (solid 2x framing) vs. a grab bar installed into drywall using commercially available drywall anchors.

Generally, the results showed:

• Grab handles installed with fasteners driven into studs or solid wood blocking material (a 2x6 connected to wall studs) met or exceeded code requirements. A grab bar fastened through the drywall into plywood backing would be expected to have a similar result one installed with 2x faming as the backing, meeting or exceeding the minimum code requirements. 
• Grab handles installed into the drywall only with drywall anchors consistently failed to meet minimum code requirements.

The worst-case scenario on the drywall anchors we tested involved pulling the bar horizontally away from the wall and placing those anchors in direct tension. In this test, all of the fasteners failed and the connection of the grab bar to the drywall failed to meet the minimum load requirements established in the International Building Code for ADA compliant grab bars.

Failures of the Fastener

Aside from fastening directly into studs, it’s also crucially important to select fasteners that are appropriate for the anticipated loads and environmental conditions. Most new ADA compliant products will include appropriate fasteners. An investigation of the failure can determine if the fasteners were improper or there were issues with the backing material.

One example where the proper selection of fasteners is critical is when mounting a shower seat. The ‘wet’ shower environment would require a non-corrosive fastener as well as a consideration of the compatibility with the mounting hardware (i.e., a potential galvanic reaction of the fastener with the fixture’s mounting hardware).

A code-compliant grab bar installation requires proper fasteners anchored into a substrate capable of safely resisting the code mandated minimum design loads. Accepted approaches include:

• Wood screws or lag bolts anchored directly into wall studs
• Wood screws into solid wood blocking installed between studs
• Specialty mounting plates or flanges designed to distribute load across multiple studs

Planning for grab bar locations should occur at the design stage or be considered in a retrofit scenario. Many building codes and accessibility standards require blocking to be installed during installation of new framing in accessible restrooms, even where grab bars will not be installed immediately, to allow for a proper future installation of ADA fixtures without destructive wall work.

Structural Engineering Expert Investigations

If you have a case involving a failed ADA grab handle, Robson Forensic has the experts to provide clarity as to the cause of the component’s failure and the relevant standards.

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

Featured Expert

David Beh, P.E., MSCE

Civil Engineer & Construction Expert

David Beh is an expert in structural engineering with nearly two decades of professional experience in the design of buildings and a variety of other structures. He has specialized knowledge in wind,… read more.