Unsafe railing in New York City (C) Daniel Friedman The Ladder Effect at Guardrailings & Stair Guards
Climbable guardrails & child safety

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The Ladder Effect of Horizontal Cable Railings - climbing children & Safety Issues.

This article describes a child safety hazard that may be present where guardrails or stair guards can be climbed, particularly by children where climbable guardrails are in our opinion an attractive nuisance. We include research on the child hazard at climbable guardrails that discuss the actual risks involved.

This article series describes and includes illustrations of cable or wire rope railings or guardrails used along decks, balconies, walkways and stairways.

We include definitions of guardrail, a handrailing or stairway handrail, and other terms that assist in understanding the building code, construction, and safety requirements that wire cable type railings must meet. Where the presence of children argues against any sort of horizontally-run guard railing member, cable railing manufacturers can provide vertical cable railing designs.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

The Ladder Effect of Horizontal Cable Railings - Safety Issues

Unsafe railing in New York City (C) Daniel FriedmanOur concern with any horizontally-run guardrail structure is that it is climbable, and also that often we find the cables are loose enough that a child can easily slip between the cables - an installation or maintenance error, not a conceptual error.

In our cable guardrail at in the photo above, the tension on the guardrail cables was pretty high but a child standing on the cable can often increase the opening size to more than 4-inches.

[Click to enlarge any image]

For researchers who argue that the "ladder effect" is not a useful construct and that children are not attracted to climbable structures, take another look at this photograph.

In our next guardrail photo shown below, where in the distance is a nice view of Seattle's Lake Washington, the horizontal guardrailing members are constructed of metal pipe and do not stretch or deflect, but they are more than 4" apart and as they are horizontal, a child could easily climb the guardrailing at this Seattle.

The ladder effect is a child hazard that pertains to any type of guardrail or stair guard that uses horizontal, climbable enclosing members.

Climbable horizontal infill of a guard railing (C) Daniel Friedman

The stretch and opening of horizontal guard cables can be minimized by placing intermittent posts at suitable intervals between the supporting posts.

Atlantis suggests no horizontal space between posts should be 4 feet on center - a spacing that I usually see has been violated by the installer.

Stair guards with loose cables or wide openings or climbable enclosing members may also be unsafe

Unsafe cable or wire guard along a stair, Queretaro (C) Daniel Friedman

Above we can see by casual observation (sagging and wide-open wire cables) that this cable type stair guard does not protect children using the stairs.

This installation is in a coffee shop in Colonia Sur in Queretaro, Mexico.

Cable guardrail and stair guard, FDR Estate (C) Daniel Friedman

Above our second photograph, shows a closely-spaced, highly-tensioned guard rail and stair guard at the Franklin Delano Roosevelt estate in Hyde Park, New York.

At least some of the cable railing suppliers offer vertical cable railings for installations where a horizontal railing is not approved or not suitable.

In our OPINION, a vertical cable guardrail adequately addresses the climbability question (the ladder effect) and if properly tensioned, might pass the opening spacing requirements.

The Atlantis company's opinion is that because of their small diameter and lack of rigidity, horizontal cables are thin and not easy to climb. [46] Indeed in our photo where kids were tugging on the horizontal cables installed in a cable railing in New York City, the cables appeared rigid enough that there was not much visible deflection.

Our field experience is that children enjoy climbing horizontal cables and other horizontally run guardrailings. Perhaps due to playground practice, it's apparent that kids have little difficulty ascending the cables. OPINION: We do not recommend any type of horizontal guardrail intermediate members that can be climbed in locations where children may be present.

Research on Child Safety vs Cable Guardrails or Stair Railings

Deflection in a cable guardrail system cannot preserve the 3-inch spacing (C) Daniel FriedmanReader Question: are there really safety or security issues for children with cable railings on decks and stairs?

15 August 2015 Barbara said:

Are there any data or feedback on security issues for children with cable railing (deck and staircase)? I am concerned that they might want to climb on the horizontal cables, but not sure if it is a serious issue.


Horizontal cables or any horizontal member in a guardrail are a child hazard as children can and are tempted to climb such a guardrail - a hazard often described as the ladder effect.

The ladder effect hazard at guardrails and stair guards remains a common opinion among safety experts (cited below) and some code officials and home inspectors, regardless of whether or not the railing was approved by local code officials.

In our opinion, the aesthetic desire for cable railings and the marketing objectives of vendors may be a factor in the removal of the ladder effect hazard from some building code restrictions on guardrail design and there may be both inadequate fall and injury reporting data as well as conflicting interests between safety and and industry vendors.

For example, Hedge (2007) completed a under the auspices of the National Association of Home Builders' Research Center (NAHBRC) and funded by and prepared for the National Ornamental and Miscellaneous Metals Association (NOMMA), an industrial association that includes vendors of cable railing systems that did not find data which supported the need for additional code language.

Readers concerned only with code violation and "legality" of cable guardrailings should check with their local building code enforcement official.

Readers concerned with child safety should also review the safety articles cited below. Istre (2003) makes clear that guardrail openings spaced or capable of being spaced more than 4 inches apart are a significant fall and injury hazard for children.

Typically there are other hazards such as the ability of the cables to be stretched or moves such that the 4-inch safety opening size can be increased so that a child could also pass through the guard.

For this reason some builders and code enforcement officials specify a 3 1/4" spacing between horizontal cables rather than the 4-inch rule of thumb used for solid balusters. Other sources we found (Ellis 2011) suggest that cable manufacturers suggest a 3-inch spacing. opening.

References discussing cable guardrailings, cable railing safety, design, construction & spacing specifications

Note: the deck building citations below are generally quiet or have little to say about child hazards, climbability, and building code compliance for cable railing systems but they do offer good construction practices and discuss cable tension, spacing, post security and strength and similar cable railing design considerations.


Continue reading at CABLE RAILING CODES, OPENINGS, LADDER EFFECT or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

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Guardrail / Railing Articles

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