High school and college football season is well underway. School districts, colleges and spectators at these sporting events should be aware of a significant safety hazard that exists on many new and most older bleachers and grandstands. Many high school and college bleacher and grandstand systems utilize aluminum extrusions for the walking surfaces, and many of these aluminum walking surfaces are “slippery when wet”.
These extruded deck boards have ridges that run parallel to the length of the extrusion. These ridges are of minimal help in improving the slip resistance of the aluminum walking surface when the spectator’s direction of travel is perpendicular to the ridges, even if a small amount of liquid is present. The effectiveness of the ridges are further reduced when a spectator’s direction of travel is parallel to these ridges. These conditions can be very hazardous to an unsuspecting spectator.
Most slip and fall accidents occur when an individual experiences an unexpectedly slippery walking surface. A wet, untreated aluminum walking surface substantially reduces the amount of available traction and creates a slippery condition. This can occur in wet and/or freezing conditions, or when a liquid is spilled onto the walking surface.
In general, walking surfaces with slip-resistance values higher than 0.50 are thought to be “slip-resistant”. A reasonable measure of slip-resistance is static coefficient of friction (SCOF). Although slip-resistance can vary from surface to surface, or even on the same surface, depending upon surface conditions and footwear. For many, this pass-fail approach created the perception that products meeting the 0.50 value were “safe,” while those that did not were therefore “unsafe.” Many in the risk and safety field have been led to believe that this 0.50 value was recognized by Occupational Safety & Heath Administration (OSHA), when in fact OSHA has never published or mandated any such minimum slip resistance value. The only reference to the 0.50 value being attributed to OSHA was in the 1994 ADA Standards for Accessible Design (ADASAD) appendix, which incorrectly attributed the 0.50 value to OSHA. The ADA was later amended via a bulletin announcement that withdrew all language pertaining to walkway slip resistance. As it stands today, neither OSHA nor the ADA has any minimum requirement for slip resistance.
In the early 2000s many bleacher and grandstand manufacturers began offering coatings and finishes to address the slippery when wet issue. Due to the competitive nature of the bidding process for public school and university projects, these slip-resistant alternatives were offered by the manufacturers as options or features that the school districts or colleges could select. Budgetary constraints often dictated that these slip-resistant finish options be eliminated, even if specified by the architect. As a result, the slippery when wet hazard remains, even on most newly constructed bleachers and grandstands.
Carl Muha, PE, has over 17 years of experience regarding the design and inspection of bleachers and grandstands. Jim Royston, PE, has over 30 years of personal injury accident investigation experience. They are ready to assist you in these and other areas.