We've pulled together a quick, easy to follow guide that walks you through the 4 simple steps to determine the best pallet rack beams and uprights to fit your specific storage needs.
1. Determine the Dimensions of Your Pallet. To do this you'll want to find add the depth and width of your pallet with the depth, width and height of the load sitting on top of the pallet. See #1 in the pallet rack illustration above.
A standard GMA pallet has the following dimensions: 40"W x 48"D
2. Determine How Deep Your Pallet Rack Upright Needs To Be. The next step is to take the depth of the load you are trying to store, that was calculated in first step, and add three inches to either side. A slight overhang on either side, we recommend 3", ensures that the weight of the pallet load sits most directly on top of the beams in your pallet rack. If you have a 48" deep pallet that you try and store on 36" deep pallet rack uprights, all the weight of your pallet is going to sit in the notches of the pallet. This added stress makes it more likely that the pallet deteriorates which could result in falling product if the pallet snaps in half. Unfortunately, we've seen our fair share of customers who want 'the cheapest pallet rack' possible and therefore put a standard pallet on a non-standard size. While it might save money up front, this setup rarely works out well in the long run. You'll either have to retrofit the pallet rack system down the road or replace it all together.
Using a standard pallet, the upright depth would be: 48"D - 3" (Left Side) - 3" (Right Side) = 42"D
3. Determine Beam Width and Max Capacity. Similarly, when calculating the width of the pallet rack beams you require, it's best to add some space between the pallet rack uprights and the pallets. We recommend 6" between pallets and 3" between the pallet and the upright. This allows the forklift operators a little bit of leeway as they move product in and out of the pallet racking system. This can reduce the amount of damage to the pallet rack and actually increase operator efficiency since they don't have to slow down as much to move product in and out of the pallet rack.
Beam width in the example above would be calculated as: 6" + 40" (Load #1) + 6" + 40" (Load #2) + 6" = 96"W
The maximum beam capacity required is simply calculated by multiplying the weight of each pallet by the number of pallets you are trying to store on each shelf level.
In the example above, each pallet weighs 2,500 pounds, so the calculation would be: 2,500 * 2 = 5,000 lbs max capacity per pair
Beam weight capacities are always calculated as a pair since you can't store a pallet on just one beam. If you already have pallet rack that works for you and you're just trying to add on to what you have, a quick short cut can be measuring the inside dimensions of the beam and the height of the beam face. Do keep in mind that the steel used to fabricate some pallet rack might be thicker than others, so this isn't always 100% accurate, but it's a good, quick rule of thumb.
4. Calculate Upright Height and Required Capacity. When determining the height of your pallet rack upright you want to make sure there is adequate room for the forklift operator to remove the load and avoid fixtures such as the ceiling, fire suppression and other obstructions that may exist overhead. OSHA recommends leaving 48" between the top of the pallet and the bottom of the ceiling. To clarify, the bottom of the ceiling in this case refers to the lowest hanging object off the ceiling. So, if there are rafters use that measurement. If there is a fire suppression line or related, take your measurement off the bottom of that system. The idea is to ensure there is enough room to lift your pallet off the pallet rack upright without getting close to hitting anything and having the pallet fall from 16' or 20' high.
In the example above, if the height of each load stored on the pallet reached 48" and the beams were each 4" thick, the minimum height for your upright would need to be: 48" (Floor Load) + 6" + 4" + 48" (Load #1) + 6" + 4" + 48" (Load #2) = 164"
Calculating upright capacity is even easier.
The capacity of the upright would be calculated as: 2 pallets per shelf level * 2 shelf levels * 2,500 lbs per pallet = 10,000 lbs minimum capacity
Specifying the right capacity could result in significant savings since lower capacity pallet rack uprights utilize less metal and therefore cost less.
Following the four steps outlined above, you'd be able to specify the following material for your project: Uprights that are at least 164"H, 42"D and can hold a minimum of 10,000 lbs and beams that are 96"W and can hold a minimum of 5,000 lbs per pair.
Conclusion
If you take a few minutes to calculate the dimensions of the pallet you are trying to store, you can quickly determine the height, width and depth of the pallet rack system you need.