Perimeter base
A perimeter base is a block-pallet bottom deck made of boards running around all four edges, like a picture frame, leaving the middle of each bay open. It supports the pallet evenly in both directions and allows full four-way entry for forklifts and pallet jacks.
Also called picture frame base, perimeter bottom, frame bottom
Reviewed
How a perimeter base is built
Bottom boards run along the two long edges and the two short edges under the corner and edge blocks, forming a closed frame. Where boards cross, they are either stacked (bottom stringerboards plus bottom deckboards) or arranged to sit flush. Inner openings let pallet-jack wheels reach the floor from any side, and the board edges that wheels cross are chamfered.
Block bottom styles compared
| Base | Layout | Entry |
|---|---|---|
| Perimeter | frame around all four edges | full four-way |
| Cruciform | perimeter plus center boards forming a cross | full four-way |
| Unidirectional | boards in one direction only | full four-way |
| Overlap | bottom deckboards plus bottom stringerboards | partial four-way |
Where it is used
The UK standard 1200x1000 pallet is a perimeter-base design, and CP6 to CP9 chemical pallets have perimeter or frame bottoms. The frame gives stable support on roller conveyors and in racks in both directions. See perimeter base pallet.
Questions
- Why use a perimeter base pallet?
- It supports the load evenly in both directions, runs well on conveyors, and still lets pallet jacks enter from all four sides.
Related
- Cruciform baseA cruciform base is a block-pallet bottom with a perimeter frame plus center boards forming a cross. It adds support under the center block in both directions.
- Unidirectional baseA unidirectional base is a block-pallet bottom whose boards all run in one direction, with no crosswise bottom boards, giving full four-way pallet-jack entry.
- Full four-way entryFull four-way entry means forklifts and pallet jacks can both enter from all four sides. Block pallets with perimeter or cruciform bases are full four-way.
- Perimeter base pallet: a block pallet with a framed bottomA perimeter base pallet is a block pallet whose bottom boards frame all four edges. How it compares with unidirectional and cruciform bases, and specs.
- 1200 × 1000 mm pallet1200 × 1000 mm (47.2 × 39.4 in) pallet specs with drawings: block pallet 51 lb. Nail counts, board feet and parts lists for each build.
- Rack storageRack storage means a pallet spans between two rack beams with nothing underneath. It gives the lowest rating, e.g. 1,558 lb racked vs 5,223 lb on the floor.
Sources
- Uniform Standard for Wood Pallets (NWPCA, now Woodpack Global), 2012 edition
- Guide to Understanding the PDS Specification and Analysis (block class, metric)
- CP pallets overview (Directpal)