Configuring & Measuring Pallet Racks: What You Need To Know
If you're considering adding or replacing rack, knowing what factors to consider and the right way to measure pallet racks is crucial. Here's a handy guide to get you up to speed.
How Much Racking Do You Need?
The most logical place to start when looking at your storage requirements is to determine the length of your racking run. This is generally the length of your warehouse, or at least the part of your facility with usable floor space for racking. Later, you’ll determine how many runs you can actually add, but for now it’s easiest to calculate the racking for a single run.
Once you determine run length, it’s time to start considering beam length. Selective pallet racking systems are made up of upright frame and horizontal cross beams. Beams generally come in standard lengths like 8’,9’, 10’ and 12’, although many different options are available from different vendors.
If you’re replacing racks, be very careful when measuring existing racking. One common mistake that people make is measuring from the outside of the uprights. Beam length is actually measured from the inside edge of each upright.
To determine beam lengths for new installations, you’ll need to factor in exactly what you will be storing. For example, if you are using popular Grocery Manufacturer Association 40” x 48” pallets, you may want to store two pallets per rack. You’ll need to factor 40” of width per pallet for a total of 80”. For building and fire codes, you’ll also need to add 5” of clearance between the uprights on either side, and six inches between the two pallets. Your total beam length, then, would be 80” + 16” for a total of 96”.
Let’s add a second example: in this case you’re still using 40” x 48” pallets but you’re storing three per rack. Your actual pallet width total would be 40” x 3 for a total of 120”. Additionally, you’ll need 5” of clearance for both uprights (10” total) and 6” of space between pallets (12” total). All in, you’re at 142”, so you’ll need 144” long beam.
One last factor to consider is the beam face. This is simply the top to bottom measurement of the beam itself. Beam face and length are factored to determine the weight that your racking system can support. Your racking manufacturer can supply all the necessary tables for these calculations.
Next you’ll need to calculate rack depth. Rack depth is determined by the width of the uprights that the beams are fastened to. Typically you’ll want three inches of overhang on both the front and the back of the rack, so you can subtract 6” from your pallet depth to determine the required rack depth. For 48” pallets you would want a racking depth of 42”. The 3” overhang allowance makes the pallets easily accessible to forklifts and is necessary for almost all selective rack configurations.
The most common depth of uprights is 42”, but many other sizes are available, including 24”, 36”, 44” and 48”. Unlike beams, uprights are measured from outside edge to outside edge.
For rack height, there are many things to consider. How high are your ceilings? What is the maximum reach height of your forklifts? What are the dimensions of the tallest pallet load you will need to store on a racking level?
Start by figuring out how much height you’ll need between the beam elevations. Take the tallest pallet load height and add a minimum of 4” of overhead clearance for forklift maneuverability. Make sure that you include the actual pallet height along with the pallet load when calculating pallet height.
Take your ceiling height or maximum forklift reach (whichever is higher) and divide by your required level spacing to determine how many levels your system will accommodate.
Putting It All Together
Take the run length you calculated at the start, and divide by your beam length. For instance, if you have a 100’ run and 12’ beams, you can fit 8 bays. You’re not done yet, however. For eight bays you’ll need to factor in the width of nine uprights at 3” apiece, so you’ll end up with another 27”. In this example, you have 1,179 inches including the beams and the uprights, for a total of 98.25’.
Once you know how many bays you can fit in the first run, you can start calculating the number of rows and row spacing in your warehouse.
Beyond uprights and beams, you’ll likely need wire decking, row spacers, post protectors and other accessories for your installation.