Pallet spacing is the horizontal clearance left between adjacent pallet loads, and between loads and rack uprights, in a rack bay. The required clearance is set by the rack design, handling equipment and local fire code.
Detailed Definition
Pallet spacing is the gap left around each load in a rack bay so operators can place and remove pallets without striking the neighboring load or the upright frames. It is planned when the rack is designed, because the number of pallets per beam level plus the clearances determines beam length. Spacing works together with vertical clearance, the gap between the top of a load and the beam above, which allows the load to be lifted off. In sprinklered warehouses, the gaps between loads also act as flue spaces for fire protection.
How spacing sets beam length
Beam length is the total width of the loads on a level plus the clearances between and beside them. For example, two 48x40 pallets placed with the 40-inch side facing the aisle take 80 inches. On a 96-inch beam, that leaves 16 inches to split between the gap at each upright and the gap between the two loads. Remember to measure the load, not just the pallet: cases or wrap that overhang the pallet edge use up clearance. The rack supplier should show the design clearances on the layout drawings.
Vertical clearance and flue spaces
Each level also needs space above the load so the forklift can lift it off the beams without hitting the level above. In sprinklered buildings, fire codes and the sprinkler standard used in the US, NFPA 13, can require open flue spaces between and behind loads so heat and water can travel. Those requirements depend on the commodity, rack height and sprinkler design, so confirm them with the fire protection engineer or local fire authority.
Keeping spacing in daily operation
Spacing disappears when loads are placed crooked, oversized loads are squeezed in, or extra pallets are added to a level. Train operators on placement and audit rack faces regularly.
Related Glossary Terms
Frequently Asked Questions
How much space should be left between pallets on a rack beam?
There is no single universal number. Rack layouts commonly leave a few inches between loads and between each load and the upright, but the right value depends on load size and overhang, the type of truck, operator visibility and fire code flue requirements. Use the clearances shown on the rack manufacturer's design drawings, and measure the actual loads, including any overhang of cases or wrap, rather than the bare pallet.
Why does pallet spacing matter for fire safety?
In sprinklered rack storage, gaps between loads let heat rise so sprinklers activate, and let water reach lower levels. When loads are pushed together or gaps are filled with extra product, a fire can spread across the rack before sprinklers control it. Sprinkler design standards and local fire codes can set flue space requirements, so changes to rack layout or load sizes should be reviewed with a fire protection engineer.