Understanding Pallet Rack Frame Capacity

Mobile storage racking

The two guiding principles of any warehouse operation are safety and efficiency. The storage solutions you use play a crucial role in safely storing and retrieving inventory, directly affecting your facility’s productivity and workflow.

Pallet racking is a high-density storage system and, depending on the materials used and the configuration, can safely store an enormous variety of items.

To ensure your pallet racking system can support the pallet load, it is vital to determine the pallet rack frame capacity. This refers to the total weight the upright frames can support.

How Pallet Rack Frame Capacity Works

Unlike the selective pallet rack’s fixed beam capacity, the weight supported by the uprights weight value is adjustable. This flexibility allows you to store heavier loads at the bottom of the racking systems and lighter loads toward the top. This reduces the risk of toppling, improves overall safety, and gives you control over the pallet rack’s total storage capacity.

There are two critical factors to consider when calculating the pallet racking’s load capacity: the pallet’s dimensions and the combined weight of the pallet and product.

Finding Beam Length

The beam length correlates to the pallet dimensions. Wider pallets require broader beams because you need to provide at least a foot of clearance to minimize damage to the goods and allow picking equipment to access the pallet.

Beam length calculations are calculated per pair of pallets. For example, if you have a 40” wide pallet, you multiply the width by two, then add 12”, giving you a total beam length of 92”, one of the most common pallet rack beam sizes. The extra length also ensures that you comply with fire and safety codes.

For this reason, some manufacturers refer to the weight capacity rating of their selective pallet rack systems using the term “capacity per pair,” suggesting an even, symmetrical placement of the load between each pair of beams.

This calculation estimates how many total beam levels are needed to accommodate your inventory, consequently affecting the pallet rack frame capacity.

Assessing Rack Height

One of the biggest benefits of pallet racking is that each beam level is height-adjustable. The vertical space between each pair of beams is called the vertical beam spacing.

Many systems feature simple yet secure keyhole slots on the uprights that let you alter the vertical beam spacing as inventory changes and supplier demand increases. For example, if the warehouse needs to store taller, bulkier loads like engines and industrial material, the beam height can be set higher to obtain the desired pallet spacing.

Most pallet rack upright slots feature the standard teardrop design. However, some teardrop pallet rack systems use alternative hole patterns, such as Keystone, Newstyle, Structural, and several proprietary styles.

Rack manufacturers recommend avoiding reducing the number of beams in the overall structure as this can adversely affect the system’s weight capacity.

The distance between the beams also affects the total pallet racking weight capacity. The load weight exerts more torque on the frame over a greater distance, so the higher the vertical beam spacing, the lower the weight capacity.

As the vertical beam spacing changes according to the application, most manufacturers rate their pallet rack frames using a standard unit of spacing, typically 42” or 48”. This rating allows you to calculate each beam’s capacity and the overall frame capacity if you make adjustments.

Finding the Upright Frame Capacity

To calculate the upright frame capacity for your needs, take the estimated maximum load weight for each beam level and multiply it by the number of beam levels in the racking section. Factor in the vertical beam spacing according to your pallet dimensions using the ratings available on the capacity chart supplied by the rack manufacturer.

Load distribution

Another factor that affects the total upright pallet rack frame capacity is how the pallets are loaded onto the frame. The structural capacity required to support a pallet relies on even distribution.

If the pallet position is incorrect, the load may weigh down one of the upright columns more than the other, resulting in an unbalanced rack and presenting a safety risk to the warehouse space. Safely loading pallets onto the racks is critical to keeping the warehouse safe and accident-free.

For example, a 96” beam may feature a listed capacity per pair of 4,044 lbs. Correctly placed pallets should result in an even weight distribution (no more than 2,022 lbs. per beam).

Height-to-depth ratio

According to the pallet rack experts at Rack Manufacturers Institute, a typical beam racking system should have a height-to-depth ratio of no more than 6:1.

For example, a standard pallet racking system with 42” racks should feature a combined frame height no taller than 252” (21 feet). The added depth provides stability to the system in case of a collision, natural disaster, or accident.

For racking systems that exceed this 6:1 height-to-depth ratio, warehouse managers can use row spacers to attach rowing or racks and add depth without compromising the warehouse floor plan.

Pallet Rack Frame

Rack anchors

Rack anchors are the industry-standard feature for securing racking systems to the warehouse’s concrete floor, reducing toppling risk and increasing impact resistance.

You can also use column protectors, heavier bracing, and end-of-aisle guard rails to prevent collisions with picking equipment, damage the rack structure, and reduce frame capacity.

Outfit Your Facility With the Best Pallet Racking Systems

Determining the correct pallet rack frame capacity for your storage system ensures a safe work environment, complies with occupational health and safety codes, and optimizes your storage space for more efficient loading and picking.

At Shelving + Rack Systems, Inc., we carry the best range of premium new and used pallet rack systems available for a range of warehousing applications. Explore our online catalog or call us at (800) 589-7225 for a consultation with our project managers and let us help you find the perfect racking system for your facility.