Block stacking refers to unit loads stacked on top of each other and stored on the floor in storage lanes (blocks), two to ten loads deep. Depending on the weight and stability of the loads, stacks may range from two loads high to a height determined by
- Acceptable safe limits
- Load stackability
- Load weights
- Pallet conditions
- Floor loading restrictions
- Weather (due to corrugated softening in high humidity)
- Vehicle lift height capacity
- Crushability of the loads
- Building clear height
Loads in a block should be retrieved under a last-in-first-out (LIFO) discipline. Hence, if highly restrictive FIFO requirements are in place, block stacking is not a feasible storage method. Block stacking is particularly effective when there are multiple pallets per stock keeping unit (SKU) and when inventory is turned in large increments, that is, several loads of the same SKU are received or withdrawn at one time.
As loads are removed from a storage lane, a space-loss phenomenon referred to as honeycombing occurs with block stacking. Because only one SKU can be effectively stored in a lane, empty pallet spaces are created that cannot be utilised effectively until an entire lane is emptied. Therefore, in order to maintain high utilisation of the available storage positions, the lane depth (number of loads stored from the aisle) must be carefully determined.
Because no racking is required, the investment in a block stacking system is low, block stacking is easy to implement, and it ables near-infinite flexibility for floorspace configuration.
