Pallet Rack Types and Helpful Tips
Authored by Pat McAssey
July 22, 2013
Pallet racking is any material handling storage system that stores materials on pallets in horizontal rows on multiple levels. Pallet racks require the use of a forklift truck to load and unload pallets onto the racks. All pallet racking, no matter the style, will increase the storage density of your warehouse, retail centers, and any other storage facility.
There are many factors to consider when choosing which style of racking is right for you:
Storage density required/desired
Building space, both floor space and height
Placement of obstructions (doors, support beams, columns, etc.)
Inventory size and weight
Selective pallet rack is the least dense and also the least expensive, and allows for direct access to each product at each shelf height. They come in two main styles, roll formed and structural. Roll formed racking is typically lighter and has horizontal load beams that are held in to place by clips, and are typically adjustable in 2 inch increments. This makes adjusting the rack heights very easy, but roll formed pallet racks cannot hold as much weight as other styles, and tend to be less resistant to impact by forklifts.
Structural selective racking is much more durable because the horizontal beams are attached to the upright beams with bolts. Both types of selective racks are adjustable and customizable, but roll formed is less durable and more prone to damage. Structural pallet rack can also be a part of the building’s structure, replacing the building’s I-beams, creating a rack supported building.
Other types of pallet rack include drive-in/drive-through, push-back, and pallet flow rack. These types allow for more dense storage, but you cannot access any given inventory item at any moment. It takes a little more planning and organization to properly utilize this style of racking, but when done properly is extremely efficient.
Drive in/through racks allow for lift equipment to drive directly into the rack’s rows. Drive through is open at each entry point allowing for a forklift to drive completely through the rack, whereas drive in is only open at one end. Drive in requires a LIFO style of inventory (last in, first out), meaning that the first pallet to be stored in a row is the last one out, and the last one to be stored is the first one out. Drive through used either the LIFO or FIFO method for storing, because pallets can be accessed from either side. Drive-in/drive-through rack is an extremely dense method of storage, because it does not require aisles between each rack system. This style can be damaged somewhat easily because forklifts travel through the rows with very little clearance on either side.
Push-back pallet rack takes advantage of depth for additional storage capacity because it can typically store between four and six pallets deep, and pallets are stored on wheeled carts that sit on top of rails. These rails are angled slightly toward the front of the racking, causing pallets to roll forward due to gravity. When a forklift loads a new pallet into a row with pallets already in it, it pushes the existing pallets back. When a forklift takes a pallet out, all of the other pallets slide forward towards the front. This a great labor saver but is also more expensive than selective and structural rack, so it depends on how dense you need your storage space to be.
Pallet flow rack is very similar to push back rack in that it takes advantage of depth and gravity for additional storage density. Pallet are placed on roller wheels at a slight incline so that pallets move to the front of the rack automatically. These systems may contain braking systems that control the speed of the moving pallets for added safety. Depending on your setup, pallet flow rack can be loaded in the back and picked in the front (FIFO), or loaded and picked in the front (LIFO).
No matter what you are shopping for, the amount of options can end up being overwhelming, making it harder to make a decision. This is especially true when deciding what type of used pallet racking is right for your material handling application. ASI carries a variety of styles and brands, some of which aren’t manufactured anymore. These styles are just as safe and function properly, but they have just been replaced with newer models.