When managing a warehouse, it’s important to carefully consider the racking systems that you install for inventory storage and retrieval. Your choice of racking system can allow you to maximize available storage space, take advantage of vertical space, increase worker efficiency, and minimize the incidence of workplace accidents.
What is Warehouse Racking?
The first purpose of a warehouse is storage. The second is the efficient retrieval of stored inventory for distribution. Racking refers to a group of inventory storage and retrieval systems designed primarily for palletized merchandise, although there are some notable exceptions to this rule, such as cantilever racking for oversized, long, or unusually shaped goods like lumber or steel rebar. The rack elevates the pallet off the ground, protects it from damage, and positions it in such a way that it may be easily retrieved by a forklift, automated retrieval system, or other tool.
Shelving, carton-flow racking, and other systems are also sometimes categorized as picking solutions to reflect the increased accessibility to unassisted workers.
Racking systems may be live, which means that they rotate stock, either by using passive forces, such as gravity and rollers, nested carts on inclined rails, or electrical systems.
How to Determine the Best Type of Racking System
When determining the most appropriate pallet racking system, your priorities should be the layout of your warehouse and the inventory you intend to store. How limited is the available floor space? If you operate a compact warehouse or want to make the most of every available square foot, you’ll need to consider aisle width and the density of the racking system.
Some designs reduce the number of aisles needed for loading and unloading; however, this also affects the stock rotation method. The two types of stock or inventory rotation that you should be aware of are FIFO and LIFO.
FIFO
In a FIFO system, the first inventory items that a worker loads into a racking system are also the first to be retrieved. This method of inventory rotation is ideal for goods that have limited shelf lives or need to be distributed soon after being stored.
LIFO
LIFO refers to a system in which the last inventory item that a worker loads into a racking system is also the first to be retrieved. This method of inventory rotation is mostly used with non-perishable goods, the distribution of which is not time-sensitive.
Inventory Type and Size
The inventory that you store also determines the type of racking system you need. Cantilever racking, for example, is not designed to store palletized inventory.
If you need your pallet racks to be available for storing and retrieving compact inventory items, non-palletized inventory, or non-standard size pallets, it may be necessary to install a type of decking.
You should account for the width, height, length, and approximate weight of the inventory that you intend to store. All these factors determine the most beneficial racking system for your warehouse.
Consult Stakeholders and Experts
As with automated storage and retrieval systems, you should consult internal stakeholders, including all management team members, regarding the ideal type of racking system to maximize the efficiency of your workplace. There are numerous considerations to consider, from the types of material-handling equipment your workers will be using to the proximity of your pallet racks to docking bays.
The height of your pallet racking system is determined, in part, by the clear height of your warehouse. The clear height is the distance between the floor and the lowest hanging object. This may be a light fixture or sprinkler system. You’ll need to know the clear height of your warehouse because when horizontal expansion becomes less feasible, vertical expansion becomes a necessity.
Do you currently use automated storage and retrieval systems or plan to in the future? The racking system you purchase should, for example, be compatible with any existing conveyor system that you employ.
Base/Floor Plates
According to the Rack Manufacturers Institute (RMI), every racking system needs to be anchored to the floor. Anchoring provides the stabilization necessary to resist seismic activity, forklift impact, and improper inventory loading. This requires bolting the base plates to the concrete floor.
Ease of Assembly and Strength
You’ll need to balance the ease of assembly against strength, load-bearing capacity, and structural stability to find the right warehouse racking system for your business.
Structural racking
Composed of welded steel components, the beams and uprights are bolted together. The primary advantage of structural steel racking is that it’s considerably stronger than roll form racking. As a result, structural racking is preferable for storing heavy loads. It’s also less susceptible to forklift impact.
For these reasons, structural racking is ideal for drive-in/drive-thru racking systems in which forklift traffic is high. However, the result of this manufacturing method is that structural racking is also more expensive, has a longer lead time, and is more difficult and time-consuming to install.
Roll Form Racking
Roll form racking is similar in assembly principle to rivet shelving. The beams have rivets or connectors that fit into corresponding teardrop-shaped holes in the uprights. Roll form racking is simpler to install than structural racking; however, it also offers less strength.
Roll form racking can be a cost-effective option for warehouses or inventory storage and retrieval systems. For example, forklift traffic and the risk of impact damage are relatively low. It’s also easier to adjust the height of roll form racks than structural racks, which is ideal for warehouses that handle a variety of differently sized products.
Upright Protectors
The uprights are vertical columns that provide structural support for the other components. Even for durable, heavy-duty pallet rack systems that are properly anchored, it’s necessary to reduce the extent to which forklifts can cause damage to the uprights of your racking system. Upright protectors reinforce the columns, providing an impact-resistant barrier or shield between the upright frames and forklifts.
Corrosion Resistance
Warehouse racking systems are available in various materials; however, racking systems made from alloy and carbon steels are susceptible to oxidation and rust. If your warehouse is humid in the summer or your racking systems are in refrigerated units, the risk is higher. The use of powder coating, galvanizing, or epoxy sealants can protect the steel against corrosion, preserving its appearance and structural integrity for years.
Aisle Space
One of the factors related to the layout of your warehouse is the available aisle space. Reducing the aisle width by using high-density storage systems can increase the capacity of your warehouse when neither horizontal nor vertical expansion is possible. However, if you employ forklift drivers, there must be sufficient space between racks to accommodate the forklift’s turn radius.
The less space there is to maneuver, the more likely your drivers are to collide with the uprights of racks. In addition, less aisle space can cause forklift drivers to load and retrieve inventory more slowly, compromising workflow. You need to account for these factors when evaluating your warehouse and racking systems.
Different Types of Warehouse Racking Systems
There are several different types of pallet rack, each designed for different stock rotation and retrieval methods, warehouse layouts, and inventory types which include:
Selective Pallet Racks
The most common warehouse racking system, the selective rack, is a FIFO system in which standard forklift trucks load and retrieve inventory from the front. Comparatively inexpensive, the selective racks allow for multiple forklifts to access the rack at the same time. Although selective racking allows immediate access to inventory, it’s also inappropriate for high-volume operations.
Drive-In and Drive-Thru Racks
Drive-in and drive-thru racks are configurable high-density warehouse storage systems designed to be accessible via forklift trucks. You can adapt the system to your business, choosing either LIFO or FIFO stock rotation methods.
In drive-in and drive-thru racks, the forklift driver enters the racking system to retrieve inventory and either exits by driving through or reversing or turning around, depending on the system. In addition to improving workflow and order fulfillment, these systems also protect inventory from damage.
Since these are high-traffic systems, they increase the risk of forklift collisions with the upright columns. Forklift collisions are one of the primary causes of racking system collapse. To minimize the risk of forklift collision, ensure there is sufficient aisle space between racks to allow forklift operators to maneuver properly. Also, consider installing shields to protect the uprights from impact damage. Ensure that your forklift drivers are properly trained.
In drive-thru pallet racking systems, the forklift driver can simply drive forward to exit the system. This is often more convenient and can reduce the risk of colliding with the pallet rack.
Cantilever Racks
The cantilever rack is designed to accommodate long, oddly shaped, and heavy inventory items. The cantilever rack has a base that stabilizes the system, anchoring it to the floor. The uprights are connected using horizontal braces and support the arms. The uprights are the vertical posts to which the bases, arms, and braces attach. The arms extend outward from the uprights and support the inventory.
The cantilever rack is the ideal storage solution for metal tubing/piping, lumber, bar stock, and other bulky items. However, cantilever racking systems are inappropriate for palletized inventory.
Push-Back Pallet Racks
Push-back racking is a LIFO pallet racking system in which the forklift operator loads pallets into nested carts that slide along inclined rails. When the forklift operator retrieves a pallet, the pallet behind it slides forward into the ready position. As inventory is loaded and retrieved from the same location, you can increase the storage density of your warehouse by eliminating the need for a separate aisle. Depending on the variety, the racks may be two to six pallets deep.
Pallet Flow Racks
Pallet flow racking systems are similar to push-back racking except that they’re designed for FIFO (first in, first out) inventory management. The inventory is loaded from the rear and slides forward to the retrieval aisle in a pallet flow system. While this requires two aisles instead of one with push-back racking, it’s also more appropriate for perishable or time-sensitive products.
Carton Flow Racks
Carton flow racking systems are functionally similar to pallet flow racks. Using a FIFO system, workers load carton flow racks from the rear. A series of rollers on inclined rails cause cartons, cardboard boxes, and other lightweight inventory items to slide forward toward the picking bay, where order pickers retrieve items.
Decking
As a warehouse racking system is typically designed for palletized inventory, using it for other purposes can require modification. If you need to use your racking systems to store cardboard boxes and cartons of varying sizes, you’ll need to install decking. In a selective pallet rack, the cross beams that provide support for pallets have spaces between them. For smaller inventory items, these spaces can cause goods to fall through. Decking comprises multiple options, depending on your budget and requirements:
Timber decking
Consisting of wooden slats that fit between beams, timber decking is cheap and readily available. However, wooden decking is less durable than many alternatives and is prone to cracking, water damage, and decay.
Steel decking
If you need a heavy-duty decking solution, steel panels form a shelf on the racking beams, providing additional support and strength. If you need to use racking outside, these steel panels can be galvanized or powder-coated for additional corrosion resistance.
Wire mesh decking
Lightweight and relatively inexpensive, wire mesh is relatively strong and provides long-term durability. If you need to store temperature-sensitive items and control moisture levels, the wire-mesh design promotes more efficient airflow. The increased air circulation reduces dust accumulation and allows light to penetrate more effectively for added visibility.
Inspections
As part of any warehousing operation, it’s critically important to inspect your racking systems periodically for damage to uprights, beams, braces, fasteners/attachments, decking, and base plates. This is also necessary when evaluating whether you need to upgrade your current racking systems.
When inspecting racking systems under low-light conditions, always wear a reflective vest so that forklift drivers can see you. You’ll need a flashlight for proper inspection where overhead lighting is unavailable. A laser level can be useful for determining the verticality of the uprights.
In addition, it’s essential that you train your workers in how to correctly load and unload pallet racks, ensuring that the weight is evenly distributed and the decking doesn’t support the weight instead of the beams. Every racking system has a weight capacity with which your staff should comply at all times. Exceeding the manufacturer’s recommended weight capacity can cause serious workplace injury and inventory loss.
Boost Warehouse Productivity With the Right Racking System
At Shelving + Rack Systems, Inc., we take industrial storage and retrieval systems for warehouses and other businesses seriously, offering a wide variety of systems for every application. Everything we sell is manufactured in the United States.
Give us a call, and we’ll help you select the best type of racking system for your warehouse, taking into account all relevant factors, from floor space and clear height to inventory type and stock rotation method.
FAQs
What is the difference between shelving and racking?
While both improve storage and organization, there is a crucial difference between shelving and racking systems. Although sometimes used interchangeably, shelving systems are designed to be accessible to human order pickers and other personnel and store various types of inventory.
Racking systems are designed, with some exceptions, to store palletized inventory for retrieval by workers operating material handling equipment, such as forklift trucks.
What is the best racking system for a warehouse?
This depends on a variety of factors that you’ll have to consider carefully. Evaluating your warehouse, you’ll need to provide detailed information to the racking supplier or manufacturer, who can advise you on the most applicable system for your needs.
This includes your preferred stock rotation/inventory management system, the available floor space, the clear height, and other factors. It also depends on budgetary constraints and expected ROI.
