If you are storing relatively long products such as lumber, steel or tubulars and wish to rack or stack them, cantilever is the preferred rack system. With a you knowledge of your inventory and our knowledge of cantilever systems, we can come together to create a well understood solution. By following the tips below a racking system solution will emerge that meets your needs. As always, CMI is available to walk through these steps

  • Based on the length and weight of the intended rack shelf loads you can establish the column spacing for your cantilever.

Cantilever column spacing

Establish your  cantilever arms under the intended load to prevent deflection, as this can cause damage to the product itself and has potentially undesirable side pressure on the cantilever arms.

To test your proposed columns spacing, place blocks or dunnage on the shop floor using the spacing proposed for the arms. Lower your product onto the blocks and evaluate the deflection. Adjust the width between the blocks until minimize the required arms while minimizing the deflection.

If you are intending on a longer row of connected columns be mindful of leaving sufficient space between your adjacent loads so you can safely load the racks with your forklift.


  • How to determine the right Cantilever arm length. The Cantilever Arm Length should always equal the product load depth.

Incorrect vs correct cantilever arm length








  • Define the  cantilever column height.

First consider the clear height in your building. Then make sure to check the lift height, clearance height, and lift weight capacity of your forklift. Depending on the cantilever style you will also need to factor in the height of the steel cantilever base (typically 6-12 inches). This base is usually considered your lowest level of storage.

Taking into account the height dimension of your load plus room to lift the load into place (4-12″), plus the height of the cantilever arm you will establish the elevation of each shelf. For safety sake you should design your column height to be taller than your top shelf to prevent your loads from being pushed off of the back of the shelf level.


  • Specifying your cantilever arm load capacity

Loading your cantilever arms

Divide the “Load” weight and divide that by the number of arms it takes to support the load without any deflection assuming a uniformly distributed load. Uneven loading will signficantly reduce the Cantilever arm capacity and introduce potentially undesired pressures in your cantilever system.







  • Spacing your cantilever columns with bracing.

Different manufacturers offer different designs for bracing between columns but it is most common to specify the brace sets be the centre-to-centre distance between columns. The manufacturer will make the brace set to allow for their column dimensions.


CMI can assist with any concerns you may have. Some of the more common questions arise when the cantilever is being placed on an uneven surface such as gravel or asphalt, or requires engineered documents for municipal permits. Additionally extra care is needed if you are installing a double sided cantilever system or plan to add weather protection to it.