How Pallet Rack Frame/Upright Capacity Works

A strong, reliable, well-designed, professionally engineered, and well-built pallet rack or pallet racking system is essential to keeping the ebb and flow of your warehouse operations smooth, organized, and incident-free. In addition to ensuring that all worker safety standards are being met at all times, you also need to guarantee that your pallet rack frame is properly constructed/engineered and that the structure is examined and maintained over time. Local regulation requires internal monthly inspection and annual professional inspection of pallet racking storage systems of all sizes. Given the load bearings of your specific business operations, each pallet rack installed on your premises should be accordingly engineered, designed, and placed.

Pallet Rack Capacity

What Is a Pallet Rack System?

Pallet racks are the go-to organizational system in the warehousing, logistics, and material handling industry. These are large storage aid systems or structures that are used to store a wide range of different capacity materials that come on skids or pallets. Pallet rack frames are available in a variety of sizes, shapes, capacity ratings, and other configurations that are suitable for different types of warehouses and storage facilities. With a modular design that accommodates various load capacities, these storage aid units typically require the use of forklifts and other material handling equipment to transport heavy pallets from one end of a warehouse or shipping and receiving area to another. By law, capacity ratings should be posted on the pallet racking system clearly stating capacity ratings so that employees can refer to weight and load restrictions to avoid overloading the racking system.

How Does Pallet Rack Frame Capacity Work?

In the warehousing and logistics industry, the term “pallet rack frame capacity” refers to and is determined by the exact distance between two beams on each level of the storage unit or the distance between a beam level and the floor. Frame capacity will change and is totally determined and dictated by the beam elevation/placement, which in turn will ultimately be determined and confirmed by a professional engineer and manufacturers. Basically, these are the portions of the storage unit that support the beams. This space is typically occupied by goods received and their storage containers or in the case of the latter, left completely empty.

Modular pallet rack frames are typically adjustable; however, beam adjustment must not be done by end user before consulting a professional racking firm or engineer. Beams cannot be moved up and down or removed entirely until an engineer has determined the proper capacity ratings depending on the beam spacing and the stated capacity of the beams and frames depending on the space capacity needed for each load or pallet.

Based on the vertical beam spacing needs of your warehouse, manufacturing, or shipping and receiving facility, it’s up to you to set the necessary standards prior to rack installation to ensure that engineering can be performed to create a safe, secure, and organized work environment. Keep in mind that the larger the space between the beams, the less weight that unsupported frame can hold. The smaller the space between the beams is, the more weight that unsupported frame can hold, but that means you also have to take special care in accounting for the size and shape of the materials being stored.

How to Calculate Pallet Rack Load Capacity

There are several important steps involved in calculating your pallet rack load capacity. Since this is a numbers game, it’s important that your calculations and measurements are as precise as possible and that they are performed by an engineer or experienced pallet racking firm.

Calculating your pallet rack load capacity involves knowing the exact load per beam level, beam and frame capacity, and beam elevation spacing. Then, you have to multiply that number by the number of beams per each section of racking. Lastly, you have to consider the vertical beam spacing, also known as the above-mentioned unsupported length of frame between levels.

Calculating Upright Capacity

Calculating the upright capacity essentially involves figuring out how much space is needed between each beam level of the storage unit. The best way to determine this is to start by measuring the dimensions of the materials or pallets being loaded. Once you have the accurate measurements, you then need to confirm the weight of each load and factor the weight into the level spacing and number of beams required to support the total weight.

Calculating Beam Capacity

Pallet rack manufacturers and suppliers have made calculating the beam capacity of each racking level simple. Unlike the frames, the beam capacity will always remain the same as stated from the original rating but will change as per calculations determined by beam spacing and frame capacity. Only the frame capacities will change depending on the beam elevation spacing. beams are normally designed as per the required capacity. The most common beams are 8’ long x 4” thick and are rated for 5,000 lbs. (2 pallets x 2,500 lbs.). But as mentioned, beams are designed by capacities required and can be as thick as 2” to 7”.

As per safety standards and protocol, load weight should be as evenly distributed as possible between the two beams on each level to prevent infrastructure failure and ensure the safety of all warehouse workers and operators.

Rating Bowing or Deflection of Pallet Rack Beams

Different parts of pallet rack frames are constructed using a variety of materials, all of which react in varying capacities based on the weight of each load. Uprights, beams, base plates, and decks are made of high-grade steel by gauge to conform to required capacities, which means that they should never buckle or bend under heavy loads or large pallets if capacity ratings are not being exceeded.

Rack beams that support the internal levels of the structure, however, may have some give or deflection when exposed to heavier loads. This is a perfectly natural engineering feat and it’s nothing to worry about. As a rule of thumb, if the beams have a deflection greater the 3/4” at the center of the beam, they may be exceeding beam capacity.

It’s up to the warehouse operations manager to decide what type of pallet rack beams are most appropriate for their specific applications and they must be calculated and confirmed through engineering. Typically, automated systems require a tighter deflection rating because system errors or miscalculations are less likely to be noticed by human operators and also require a higher degree of engineering.

Calculating Deck Capacity

Pallet racking wire mesh decks are stable and durable structural additions that ensure the even distribution of pallet loads throughout each level of storage unit. They prevent the units from collapsing on themselves due to uneven weight distribution in one area. Standard wire mesh decking is rated for UDL capacities of 2,000 lbs. to 25,00 lbs., meanwhile other custom sizes can be manufactured when required.

Wire mesh decks are created to support pallets with uniformly distributed loads that do not exceed the rated capacity. The rated capacity does not apply to point loads, as they are also not designed to support full pallet loads. Mesh decks are merely used as a safety feature in case the pallets are misplaced on beams and in case items fall off pallets on to workers and material below. Proper pallet placement should always require the pallet to be fully resting on front and back beams.

Engineers use two standard load classifications when calculating the maximum rack capacity per level of each storage structure: uniform loads and point loads.

Uniform loads equalize the pressure from one static surface to another. Their job is to guarantee that the weight is evenly dispersed from one end of the structure to the other.

Point loads create uneven weight distribution throughout the structure without necessarily compromising its durability and integrity. Weight is transferred inconsistently in the sense that one section bears a greater load than all other parts.

Contact Canadian Rack Technologies for Pallet Racking Systems

Canadian Rack Technologies Inc. buys and sells new and used pallet racking, industrial storage systems, and warehouse equipment. We also provide turn key full service packages which includes engineering, layout and design, supply, delivery, professional installation, as well as annual inspection programs for our clients. If you require to determine capacity ratings, capacity signage, engineer reports, or any related service as mentioned above please contact us today to learn more


Kevin Ausman is the founder of Canadian Rack Technologies. He has over 30 years of experience in providing safe and efficient turn-key storage solutions and he specializes in pallet racking, pick systems, industrial shelving, mezzanines, cantilever racks, and more. Kevin is dedicated to providing great customer service, listening to client’s needs, and supplying the best products available.

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