Stackable pallets by footprint

Four footprints

Stackable pallets are judged by the load on the bottom one. At the common size the range runs 3,000 to 30,000 lb static; the beverage and drum sizes top out at 30,000 lb static on the PHS Plastic list.

A stack worked out

Take a stackable rated 20,000 lb static. The bottom pallet carries the pallets above it, so with each loaded pallet weighing 3,718 lb it can hold 5 above, a stack of 6. With 7,760 lb per pallet it can hold 2 above. This is a ceiling on a flat floor for a still stack, not a promise for a stack that moves or waits.

Choosing between the four

For stackables, the footprint follows the load more than the lane. A beverage plant buys the beverage size because its cases are laid out for it; a chemical store buys the 48 x 48 in size because four drums fit; a general warehouse buys 48 x 40 in because its racks and trucks expect it; a retail display buys 48 x 32 in because the product is light.

If your load does not match any of those, the common size is the safe default. It carries the widest range of ratings, from 3,000 to 30,000 lb static, and the most models to choose among, and it fits the most racks. The cost of leaving the default is a thinner sheet and fewer alternatives if a supplier fails.

• Match the footprint to what rides on the pallet.
• Read the static rating against the stack, the dynamic against the forks.
• Ask for a racking load if beams are involved.
• Ask for entry type: 4-way if you use a pallet jack on all sides.

Questions to put to the maker

• Does the pallet have a lip or a raised edge to hold the load in a stack?
• Does stretch wrap or a top frame change the stacking guidance?
• Does the stack rating assume a closed deck on the pallet above?
• Is the rating the same on a slick floor, a conveyor and a rack?
• Is the rating taken on a rigid load or a flexible one?
• What is the pallet's empty weight, so the load on the bottom pallet can be added up?
• How long does the static rating hold before creep sets in, and at what temperature?
• Is the static rating for a stack of the same pallets, or for one pallet on a flat floor?
• Does the sheet give a rating at the cold end of the temperature range you work in?
• Is the dynamic rating printed next to the static one, and for which handling method?

From the dock

• Warehouse floors are rarely flat; a slight slope turns a safe stack into a tall lever.
• Plastic gets stiffer in the cold and softer in the heat, so the same stack behaves differently in two seasons.
• Weigh a sample loaded pallet before trusting any estimate; stacked weight grows faster than people expect.
• Pallet jacks need clear entry on the bottom; feet and runners that block a wheel make a slow dock.
• Mixed loads stack worst: a heavy case on one corner can cost more than a light load on the whole deck.
• Stacking frames and corner boards spread load; they cost a few cents and save a collapsed pile.
• Label every stack with its pallet model so the rating being relied on is the one on the sheet.
• A stack leans before it fails: watch the bottom pallet's corners for bowing under a full load.
• Forklift tines catch deck edges; closed decks with chamfered edges suffer less from rough entry.

Words on this page

Footprint

The length and width of a pallet deck. It is chosen to fit the container, the drum, the bag or the receiving rack.

Closed deck

A solid deck that keeps small items and torn bags from falling through and wipes clean on top.

Runner

A continuous rail under a pallet. Runners lie flat across rack beams but stop pallets from nesting.

Pallet jack

A hand or powered truck with two forks, used to move a pallet short distances.

Dynamic load

The weight a pallet holds while it is moved by a forklift, pallet jack or conveyor. It is lower than static because motion adds shock.

Open deck

A deck with slots or a grid, which drains water, sheds dust and weighs less than a solid one.

Stretch wrap

Elastic film wound around a loaded pallet to hold the load together.

HDPE

High-density polyethylene, a tough resin used in many plastic pallets, valued for strength against its weight.

Bulk bag

A large woven bag, often sold as a Super Sack, that holds a ton or so of powder or granules and sits on a square pallet.

Creep

Slow, permanent bending of plastic under a steady load. A pallet can hold a load for an hour and bow under it after a month.

UL

Underwriters Laboratories, a safety testing body that publishes fire test standards, including one for storage pallets.

Polypropylene

Another common pallet resin, lighter and stiffer than some others, with its own behaviour in the cold.