Advanced Guide to Cantilever Rack
While this guide is meant to assist you in choosing your rack, it is still beneficial to consult with one of our professional solutions specialists. They have been working with this material every day for years and are aware of ALL the tips and tricks concerning cantilever racks. Please feel free to call us at 800-598-5532 to discuss your planned layout.
Cantilever Rack, also known as furniture or pipe rack is a great solution for storage of long, bulky materials such as lumber and PVC or metal pipes. Furniture rack is a style of cantilever racking that can be decked to provide static storage similar to pallet racking, with the advantage that it provides easier storage and retreival of bulky or oddly sized material than traditional pallet rack. Cantilever rack is a very efficient means of storing material. The storage density with cantilever rack can be very high if you plan out how you will use it efficiently, but generally cantilever rack’s flexibility makes it a very popular storage solution with near immediate return on investment.
Cantilever Rack Uprights
Like pallet rack, cantilever has specific components that work together to create larger bays and rows of storage. Uprights are the main structural components in any cantilever rack installation. Uprights work with bases (when referring to uprights below, we are speaking about complete upright/base combinations) to create the ‘backbone’ of the rack. Uprights are available in single, or double sided configurations – with the only difference between the two being that with double sided uprights, you can store material on both sides of the rack. Like pallet rack, there are many different makes and brands that do not all work together. You must match the same make arm and base to build a complete unit.
Please Be Aware – NEVER put arms on the back side of single sided cantilever rack. Even if the upright has holes to hold arms on both sides, this is a very dangerous practice and should be avoided at all costs.
Cantilever Rack Arms
Similar to pallet rack beams, cantilever arms make up the actual ‘levels’ that are used for storage. The arms are typically adjustable on the upright to create shelf levels of whatever height are needed. Arms can be straight or inclined to hold goods that may roll off. Some arms even come with a “lip” that attaches to the end of the arm to prevent loads from slipping off the front of the rack.
Cantilever Rack Braces
The last component of cantilever rack is bracing. The braces go between uprights and stabilize the rack laterally. Braces are not intended to hold loads and should only ever be used to connect and brace the uprights in a row. The braces will be the same length as the spacing between uprights.
Cantilever Rack Assembly – Putting it all together
Let’s start the same way as with pallet racking. In order to have an effective and efficient system, it is first important to think about what will be stored. We’re going to start by measuring the load. The big difference between cantilever rack and pallet rack however, is that you need to make sure that if your load consists of multiple components you’ll want to make sure that you take into account the measurement of the entire unit load and not just a piece of the load. (see figure 12)
Step 1 – Arm Length & Lateral Spacing
The depth that you arrive at using the above measurements will be the minimum arm length necessary for your product. Please Note – the depth of your load should not exceed the length of your arm. The rated arm capacities of cantilever rack will not be correct if you improperly load the racking. (see figure 13 for correct arm loading techniques)
Step 2 – Load Deflection & Lateral Spacing
Lateral spacing is the distance from the center of one upright to the center of the next. To determine the correct spacing between the uprights you’ll also need to take into account load deflection. Load deflection is a very real concern when using cantilever rack to store long items. When designing a cantilever rack system, you should try to use the fewest number of arms to store your loads. However, since deflection may damage your load you should also strive to keep deflection to a minimum. A good method to determine the lateral spacing needed is to use blocks of wood placed on the ground. Place your load on these blocks to check for proper support. If two blocks yields too much deflection, try three – if that’s too few, try four. When running these tests, you must use the correct spacing method shown in figure 14. The Load should overhang the end arms by 1/2 of the distance from the center of one upright to the center of the next upright.
Step 3 – Determining Upright Height
As with other rack types, to determine the height of your uprights, you must consider ceiling height, lift truck reach and any other items that may interfere with the top of your racking. This can incluude sprinklers, ceiling joists, and lighting, among other things. Figure 15 shows the measurements you need to arrive at the total upright height. These measurements include the actual load height, the clearance between the top of the load and the bottom of the next shelf (6″ is recommendedand), the height of the arms and the height of the base. Adding these numbers will give the overall upright height needed.
Notice in the figure that a load has been placed directly on the base. This is not only acceptable – it is recommended and does not diminish the capacity of the upright. A commonly recommended practice is to place your heaviest load on the base because it doesn’t subtract from the overall upright capacity.
Step 4 – Determining Needed Capacities
In a properly loaded cantilever rack, each arm supports an equal part of the load’s weight. To arrive at the necessary arm capacity, first determine the number of arms needed to hold the load and divide the load’s weight by that number. In figure 16 below, there are three arms supporting an equal part of a 6000 pound load. This would give you a needed arm capacity of 2000 pounds.
To determine upright capacity, simply multiply the number of arms per side by the load on each arm. In figure 16 below, since there are four arms each holding a weight of 2000 pounds, the required minimum capacity of the upright would be 8000 pounds.