14 Jun 2017

Adherence To ICC Standards For Aluminum Bleacher Loads Prevents Collapse And Potential Catastrophe

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 aluminum bleachers elevatedBy Gerald Dlubala

Can your aluminum bleachers handle the loads and stresses put on it by spectators, weather and outside forces?

When looking over your bleacher seating wrapped around or alongside your venue, your thoughts naturally turn to memories of great events that took place there.

That includes the game day fans, faces painted, dressed in home colors, screaming and yelling for their home team.

It’s enough to bring a smile to your face. But those same bleachers, if left uncared for or installed improperly, can also be one of the most dangerous places around, able to cause harm to a multitude of people in one fell swoop.

We’re talking about bleacher collapse, and although it’s on the decline, it is still a very real possibility and still happens, generally with catastrophic results.

As recently as January of 2016, in Columbus Ohio, a bleacher railing failed on the grandstands at a high school football game sending the rowdy, cheering, yet unsuspecting fans in a forward motion, all falling over the person in front of them in a domino fashion, until landing on the ground.

Because bleachers hold fans that are in constant movement, causing shifting of energy and loads in every direction at random times, your aluminum bleachers should always be installed by professionals, with strict adherence to the codes and standards set forth by the ICC Standards on Bleachers, Folding and Telescopic Seating, and Grandstands, (ICC 300-2012 IS-BLE), and be inspected by authorized personnel at minimum on a yearly basis.

Aluminum Bleachers And Safety From The Start

Whether your bleachers are interior or exterior based, their construction features and materials should be weather resistant. Resistant to rust, rot, splintering and extreme weather damage, aluminum is preferred for long term, group-seating capacity.

The fasteners and joining mechanisms used in the construction should also be made of approved, corrosion resistant materials, such as aluminum, copper, or zinc.

Installation of outdoor bleachers is mandated to be greater than or equal to 10 feet from any adjacent lot lines and buildings located on the same lot, with the exception being that the exterior walls and openings of that adjacent building are protected in accordance with local building codes.

Indoor bleachers will sometimes be installed in corrosive friendly environments, such as around indoor swimming pools. These types of bleacher installations must be done using corrosive resistant materials throughout.

Structurally speaking, bleachers, folding and telescopic seating, as well as the simplest of grandstands need to be constructed with a uniform live load tolerance of at least 100 pounds per square foot, with all components manufactured from corrosion resistant materials.

Design Load Specifics For Bleachers And All Tiered Seating

  • Tiered Seating. Obviously the main component, and purpose for the structure, the tiered seating must be constructed to tolerate a minimum of 120 pounds per lineal foot. This applies to all bleachers and grandstands.
  • Stair and Walkway Treads. Being a focus of constant and omnidirectional movement, stair treads, walkway and aisle treads must be designed and constructed to able to resist a minimum concentrated load of 300 pounds over a 4 square inch area at any given time.
  • Handrails and Guards. Handrails and guards have specific load requirements for both general loads and more direct, concentrated loads. While the attached handrails and guards must be able to resist loads of 50 pounds per linear foot applied in any direction across the top, they must also be resistant to a single concentrated load of 200 pounds, applied in any direction, along and from any direction along the top of the handrail or guard. Regardless of the type of load needed at any specific time, any support structures, elements, or attachment devices used must be designed to transfer the load to the structure itself.
  • Guards and Infill Components. The balance of the structure components, such as the intermediate rails not being used for handrails, any balusters, kick plates, baseboards, and any other panel fillers, must be constructed so as to resist a horizontally applied load of 50 pounds per square foot of area. This must be accomplished while staying within the standard for openings (Less than 4-inch sphere) between bleacher components such as in between railings and spaces under footboards.

Bleacher Loads And Sway

The above bleacher components are direct load concerns, but bleacher structures are subjected to other types of loads as well, simply due to their primary function. That is to provide seating for spectators while still allowing them to move freely about.

And when considering exterior bleacher installation, there has to be consideration taken for load resistance as it is affected by weather and climate situations.

Consideration, measurement, and standards must be met for bleacher load resistance with respect to horizontal sway.

This is the bleacher’s resistance to lateral forces produced by the movement of spectators in the seats, whether sudden or in a uniform, concerted motion.

And parallel sway is measured differently than perpendicular sway.

  • Parallel Sway, described as the resistant force applied to seating, parallel to the seating, at the footboard level of each row of seating, must be at least 24 lbs per linear foot.
  • Perpendicular sway, as the name suggests, is measured perpendicular to the seating, at the footboard level of each row, at 10 lbs per linear foot.

These loads get more complex when combining the load possibilities, as parallel and perpendicular loads are not always applied in a strict single direction pattern.

Using various load and factor formulas, strength design and stress design can be measured, manufactured, installed and tested so that they are known to be at acceptable limits.

Foundations And Ground Support

Foundations or ground support for the bleachers can affect load resistance as well. The resistance of the load bearing foundation or ground support must be approved.

If the bleacher installation is an interior structure, they must be supported on the facility floor, which must be an approved support.

When those bleachers are telescopic, moving or folding, the facility floor must meet the standards as to be designed to adequately accommodate both live and dead loads, due to the continuous movement of the bleacher structure.

Awareness Of Bleacher Load Keeps Fans Safe And Secure

Modern day bleachers are unique structures. Lightweight and durable while being, in some instances, movable, they have the ability to handle tremendous amounts of fans and spectators while also remaining low maintenance.

But while accommodating those large crowds, bleachers are subject to an endless combination of load forces on the structure and components, and those forces are based on much more than just occupancy limits.

There are individual and group movements, climate and weather conditions, and multiple combinations of these two sets of conditions.

All of this movement and motion puts an inordinate amount of stress on the bleachers and individual bleacher components.

Add in weather-related factors, such as wind, rain, and snow, and those loads due can be multiplied exponentially.

Every handrail, connector, fastener and other bleacher component has a function in load resistance, dispersal, and stress design.

Your responsible ownership, management, and maintenance of your bleachers, including yearly inspections by qualified individuals, will keep your bleachers within ICC standards and leave both you and your visitors confident that your bleachers are safe, secure, and able to handle whatever loads and actions are thrust onto them.


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