Pallet racking is designed to withstand the constant stresses of pallet loads and the wear and tear of regular loading and unloading. But at some point, racking components can be damaged by errant forklift contact, by loading beyond the rated capacity, or by other forces such as seismic events. When you spot a damaged component, how do you know if the damage affects the structural integrity of the racking such that it should be repaired?
The RMI (Rack Manufacturers Institute) is vague on responses to damage, other than stating that “damaged racks should be repaired or replaced.” But there are no definitions of “damage” other than RMI specifications and industry-accepted standards relating to damage to uprights, beams, the out-of-plumb pallet racking damage tolerances, and bracing.
Pallet rack manufacturer Steel King also offers a guide to assessing damaged pallet racking, and the RMI offers a document with guidelines on assessing and repairing racking components.
In some situations, structural pallet rack damage is so obvious that mathematical formulas aren’t needed to determine that repairs are needed.
“I have walked through warehouses with loaded double-face selective racking where the bottom of an aisle upright post is so damaged that the post is barely touching the floor, yet the rack is still standing,” says Arlin Keck, P.E., Corporate R&D Engineer at pallet rack manufacturer Steel King.
Should such an upright post be repaired or the upright replaced?
“Absolutely! The bays adjacent to the damaged frame need to be immediately unloaded and the area taped off until the damaged upright is repaired or replaced. The only thing holding up the damaged frame is the upright behind it and the row spacers tying the back-to-back rows together,” Keck says.
If that were to happen to a single-face row of selective racking, the situation could easily be worse.
It’s the kind of pallet rack damage that warehouse operators should spot through ongoing observation of racking – and then address the problem immediately.
Encourage Employees to Report Suspected Pallet Rack Damage
Warehouse employees should be encouraged to point out pallet rack damage. “Management needs to cultivate an atmosphere conducive to reporting any perceived problem within a racking system,” Keck says.
But what about seemingly minor dents or bends in upright posts and bracing, beams, row spacers, or other structural componentry? Any noticeable change in a component’s original shape or positioning should be noted and discussed with management. If there are questions about the severity of the pallet rack damage, a qualified inspector should be called in.
Common Structural Issues to Watch For
There are some common structural issues that should especially be watched for 1) pallet rack damage to an aisle post of an upright frame and 2) disengagement of a beam connector from the upright post.
Damage to aisle posts, as noted above, is common simply because aisles are centers of activity. Post guards and other safety accessories can prevent some damage to aisle posts.
Beam connector disconnections are not typically an issue with bolted beam connections but can occur in systems where beams have pinned connections and safety clips. The safety clips are occasionally broken off, allowing the beam end connector to disengage from the post.
“It’s imperative that broken safety clips be replaced with new safety clips, or with through-bolts, and that damaged beam-to-post connections be replaced with new beams,” Keck says.
Structural Steel Is More Resilient
The type of steel used for the uprights – cold-formed or structural – is another factor that needs to be considered when inspecting racking.
“The capacity of an upright is dependent on the cross-sectional area and shape of the upright posts,” Keck notes. “For example, for cold-formed posts, approximately 40% of the total capacity is a result of the cross-sectional area and 60% is due to the cross-sectional shape; whereas, for a structural post, 60% of the total capacity is due to the area and 40% is due to the shape. Obviously, a dent to a cold-formed post is more detrimental to capacity than the same dent to a structural post,” he adds.
There are certain situations where damage to rack components is more critical to structural integrity and stability, and these situations deserve immediate attention:
- Warehouses or industrial facilities located in high-risk seismic regions, such as seismic design category D, E, and F regions
- Racks supporting heavy loads or loads with high-risk replacement, repair, or loss-production costs should the product be damaged, such as die storage racks
- Racks supporting hazardous materials
- Racks, where the anticipated maximum applied loads, are very close to the rated capacity of the undamaged racking
Another Factor: Legal Considerations
Minor dents and scrapes might not affect the structural integrity of a racking system, but Keck notes that because of the litigious atmosphere within the U.S., racking system operators should err on the side of caution when considering how to respond to deformities in structural elements.
Safety also should remain a prime objective, he adds. “You certainly want to maintain a safe working environment – safe for people in a warehouse, safe for the products being stored, and safe for the racking system and building,” Keck says.