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Glossary

Bottom deck

Reviewed

Definition

The bottom deck is the set of deckboards (or a panel or perimeter frame) on the underside of a pallet, which bears on the floor, conveyor or the unit load below. A GMA-style 48x40 has 5 bottom boards: two 5-1/2 in lead boards and three 3-1/2 in interior boards. Single-face pallets and skids have no bottom deck.

On this page
  1. What the bottom deck does
  2. How it is laid out on stringer pallets
  3. Bottom deck styles on block pallets

What the bottom deck does

  • Spreads the load onto the floor or onto the pallet underneath when unit loads are stacked
  • Ties the stringers or blocks together so the pallet resists racking and lateral collapse
  • Gives conveyors and automated systems a flat running surface

In a stack, the second pallet from the bottom has the most stressed bottom deck, because it carries the loads above it on its bottom boards.

How it is laid out on stringer pallets

Bottom boards must stay clear of the stringer notches. On a GMA-style 48x40 the two lead boards sit at the ends and the three interior boards are grouped between the notches (an "interior cluster" at 15.00, 22.25 and 29.50 in from the end), leaving 9.5 in openings over each notch and 3.75 in gaps between the inner boards. Bottom lead boards are often chamfered for pallet-jack wheels.

Bottom deck styles on block pallets

Style Description
Perimeter base boards around all four edges, like a picture frame
Cruciform perimeter plus center boards forming a cross
Unidirectional bottom boards running in one direction only
Overlap bottom deckboards plus bottom stringerboards

Questions

Does a pallet need a bottom deck?
Not always. Skids and single-face pallets have none, but a bottom deck is needed for stable stacking, conveyors and most racking.
Why does the bottom deck have fewer boards than the top?
Fewer bottom boards save wood and leave openings for fork notches and pallet-jack wheels, while still spreading the load on the floor.

Sources