Pallet Rack Basics: Upright Frame Components
How much do you really know about pallet racking? You may think this an odd question. After all, isn’t knowing that you have or are considering a pallet rack, enough? You could make a strong argument on the pros and cons of that question.
It may not be required to know the name of every element of the equipment. But consider this—when the time comes to replace or repair due to wear or accident, don’t you want to know what you’re buying? Of course. And knowing some basics of the equipment you rely on is never a bad thing.
The components that make up pallet rack frames can vary but are mostly straight forward.
The following is a basic sampling of upright frame components and some accessories.
Baseplate or footplate
A baseplate is the foundation of any rack. It provides stability and a connecting point to anchor the rack to the floor. The size of the baseplate depends on two primary characteristics:
- The load the rack is expected to hold
- Seismic conditions
Column or post
Each upright frame has two columns or posts. Typical or standard upright column sizes vary, but a common size is three inches by three inches. Other sizes are available and manufactured according to custom requirements.
Columns come in open-back and closed-back styles. The closed-back, or tubular, style is most common in structural frame design and is manufactured as a solid tube — for added strength, durability and capacity. The open-back style is most often seen in roll-formed frame design but is also common in standard structural frames.
Both types offer several options for connecting the crossbeam, such as slotted, structural and teardrop, which is the most common.
The bracing for pallet racks often are horizontal or diagonal. Its purpose is providing additional support/strength to the rack. These are located between the vertical column posts with the quantity determined by the rack’s height.
Anchor bolts (cement frame anchor)
Having your pallet racks anchored to the warehouse floor isn’t just good practice, it will help you avoid one of the more common citations from OSHA. Several anchoring bolt types are available. However, the two most common are wedge anchor bolts and strike anchor bolts.
Each does the job, but before selecting one over the other, you should consult an engineer or local building codes to determine the best option.
These are generally found in c-channel posts and are another piece of steel [usually] welded into the lower portion of the c-channel frame. Its purpose as implied is providing additional strength to support the load on the rack.
Not all frame reinforcement is compatible with every method of connecting crossbeams. You should always make sure to ask if the type of frame reinforcement works with your racks.
In a perfect world, floor slabs are perfectly level. Unfortunately, the world of warehousing is seldom perfect and you very likely have a space between the floor and the rack base. Shims provide that leveling needed to ensure a safe and level rack.
The most common uses for shims are for cross aisle and down the aisle leveling. The Rack Manufacturing Institute offers recommendations for using multiple shim packs, often requiring welding the shims together and anchoring the shims as part of the overall rack anchoring.
Cant-leg or offset columns
Designed to minimize damage from forklifts, cant-leg and offset columns increase safety while reducing rack damage. The front leg of the rack is recessed up to half the depth of the rack. While these do decrease damage from forklifts, the components are expensive to engineer.
Similar in purpose as the cant-leg, the slant-back also minimizes damage to the rack caused by forklifts. This design “slants” the forward post nearly back to the rear leg while a base on the floor provides vertical stability. Slant-back columns allow for better maneuvering by forklifts in selective and drive-in racks.
There are also several accessories offered for pallet rack frames
Here are a few described:
Row spacers: Used when pallet racking is placed back-to-back. Row spacers offer additional strength and support for the racks. The spacers also provide necessary flue space for compliance with fire and building codes.
Column guards: Sometimes also called post protectors, these components protect the post from forklift damage. Placement of column guards is frequently on the end of pallet rack rows where most forklift traffic occurs. However, you can certainly use these wherever the need exists.
Column guards are often anchored to the floor although some are bolted to the vertical posts of the rack.
Having a good understanding of the uses and types of components that make up your rack systems can save headaches when it comes to repairs and selecting new racks.