Interlocking stacking
Also called: interlock stacking, brick stacking, cross stacking
Interlocking stacking is a stacking pattern where alternate layers are rotated or shifted so each case bridges the joints between cases in the layer below, like bricks in a wall. It ties the load together but reduces compression strength compared with column stacking.
In depth: Pallet stacking patterns: column, interlock, pinwheel and brick
An interlocked load resists shifting because each case is held by the cases around and below it. The cost is compression strength: case corners no longer line up, so walls bear on the middle of the case panels below.
Trade-offs
| Factor | Interlocking |
|---|---|
| Stability | Higher than column stacking |
| Box compression strength | Lower than column stacking |
| Common uses | Mixed or light loads, loads handled often, short loads |
| Variants | Brick (offset), rotated layers, pinwheel |
Why it matters for pallet design
An interlocked load is stiffer as a whole, which can help it span pallet deck gaps and support areas (load bridging). The load on the deck is also spread more evenly, since case corners do not always land in the same place. PDS and LoadSync describe it as "Boxes, Interlock Stacked" in the unit load specification.
On a spec sheet or RFQ
State "interlock stacked", with the pattern drawing, cases per layer and number of layers. If the bottom layers must be column stacked for strength, say so.
Common confusions
Interlocking is not always safer. A tall, heavy load of weak cases can crush in an interlocked pattern that would have survived column stacked with a stretch wrap and corner boards.
Related
- GlossaryStacking patternA stacking pattern is the arrangement of cases on a pallet: how they are placed within each layer and how each layer relates to the one below. The main choices are column stacking, which maximizes box strength, and interlocking patterns, which improve stability.
- GlossaryColumn stackingColumn stacking is a stacking pattern where every case sits directly on top of the case below, with corners and walls aligned through the full height of the load. It keeps the most compression strength but is less stable than interlocking.
- GlossaryPinwheelingPinwheeling has two meanings. In palletizing it is a pattern where cases are arranged in rotated groups around the center of each layer, often leaving a small void. In trailer loading it means turning some pallets 90 degrees so more fit on the floor.
- GuidesPallet stacking patterns: column, interlock, pinwheel and brickColumn stacking puts each box directly on the box below and keeps the most compression strength. Interlocking patterns (brick, pinwheel) rotate alternate layers so boxes overlap, which adds stability but can cut stacking strength sharply. Many loads use columns with tie sheets, or interlock only the top layers.
- GlossaryUnit loadA unit load is a group of items, usually cases on a pallet or slip sheet, secured together so it can be stored and moved as a single unit by a forklift or pallet jack. It includes the pallet, the packaging, the stacking pattern and the stabilizers.
More in Loading and shipping
- GlossaryCube utilizationCube utilization is the share of the available volume, in a pallet footprint up to its height limit, a trailer or a container, that is actually filled with product. It is usually expressed as a percentage.
- GlossaryFloor loadingFloor loading is shipping cases or bags stacked directly on the floor of a trailer or container, without pallets. It fits more product in the vehicle but must be loaded and unloaded by hand or with special equipment. The term is also used for the load a floor can bear per unit area.
- GlossaryFreight densityFreight density is the weight of a shipment divided by the volume it occupies, measured at its outside dimensions with the pallet included. In the US it is given in pounds per cubic foot (pcf) and is the main factor in most LTL freight classes.
- GlossaryFTL (full truckload)FTL (full truckload) is a shipment that uses a dedicated trailer from origin to destination, with no terminal handling. A 53 ft dry van takes 26 standard 48 × 40 in pallets loaded straight or 30 turned, single stacked, subject to the legal weight limit.
- GlossaryLoad barA load bar is an adjustable steel or aluminum bar fixed across the inside of a trailer or container, either wedged between the walls or locked into wall track, to keep pallets from sliding during transit. Horizontal decking beams also let a second tier of pallets be carried.
- GlossaryLoad overhangLoad overhang is any part of a unit load that extends beyond the edges of the pallet's top deck. Unsupported case edges lose compression strength, get damaged in handling, and increase the measured size of the shipment.
Last reviewed 2026-09-24. 218 words.