Four Wall gaylord boxes around Boston

The step up

Adding a fourth layer raises the commonly cited range to 1,500 to 2,200 lb, roughly a third more than triple wall at the top. The extra layer also stiffens the wall, which matters for stacking as much as for load. Container Exchanger puts common four-wall heights at 36 to 41 inches.

Who needs it

Shops in Lawrence, Lowell and Woburn that ship heavy parts ask for four-wall and a full flap bottom first. A foundry or fabricator that needs a box to survive a trip on a forklift and a trailer, and then another trip, is the typical buyer. Used four-wall boxes are not common, so ask early.

Reading the range

A range from a seller is not a rating for the box in your hands. The maker's number for that specific board is the one to trust, and a used box is rated lower. We attribute figures to who published them for exactly this reason.

When four walls are worth it

A four-wall box is a response to a specific load: dense, heavy, and likely to be stacked. Castings, metal parts, dense minerals and wet-pack product are where the fourth layer starts to make sense. If your load is under half the rating of a three-wall, a four-wall is more box than you need and more weight than you want on a trailer.

Four-wall boxes are less common than three-wall on the used market, so ask early and say what you will accept in return. A request that allows a good five-wall as a substitute is easier to fill than one that insists on exactly four. Describe the load in a sentence and let the reply choose.

Checking a used four-wall box

Start at the bottom edge. A heavy load has probably pressed the lower few inches of wall against the pallet, and board that is crushed there will not stack. Then check the corners, where a fork or a rough landing leaves a split or a flattened edge. A used four-wall with a clean base and square corners is a capable box. One with scars at the base is a Grade C at best, whatever its age.

Questions that settle a purchase

Ask what the box carried, how many trips it has made, and whether it was stored under cover. Four-wall boxes are built for demanding loads, and the history of the previous load tells you more about remaining strength than a visual check.