Hardwood and pine pallets

Hardwood pallet lumber, the yellow-white and brown boards of oak, poplar and mixed species, is dense and stiff. At the same thickness it carries more and stands up better to a fork driven in hard, which is why heavy-duty builds lean on it. The cost is weight: a heavier empty pallet is more freight and more to lift by hand. Hardwood boards also vary more in colour and grain from board to board.

Southern yellow pine and other softwoods give pale, even boards that are lighter for the same size. For light and medium loads, clean freight such as food and retail goods, and pallets that are lifted by hand or shipped by weight, softwood is usually the right lumber. To carry more, a softwood build adds boards or thickness rather than changing species.

The lumber changes the board sizes the design needs. Pallet makers size boards to a load in PDS, the Pallet Design System, which takes the species into account: a deck that works in hardwood at one thickness may need to be thicker, or have more boards, in pine. Board feet set much of the price, so the cheaper lumber per board foot isn’t always the cheaper pallet. We quote the lumber that suits the load, and say why.

Fresh-sawn lumber of either kind is wet. Wood below 20% moisture content won’t support mold, so if your pallets sit closed up in trailers or containers, or carry food, ask for dried lumber or kiln drying and it is written into the spec.

Nails hold differently in hardwood and softwood. Dense hardwood grips a nail hard but can split if the nail is too big or too close to an end; softwood splits less but holds less. Pallet builders choose nail type, length and spacing with the lumber, which is one more reason the species belongs on the written spec rather than being left open. Mixed builds are common: hardwood stringers carry the load while a softwood deck keeps the weight down.

Hardwood boards are usually heavier in the hand, darker and closer-grained; pine is paler, lighter, resinous and often knotty. Mixed hardwood varies from board to board, which is normal. If one species matters to you, write it on the sheet, because otherwise a mill uses whatever lumber it has. Oak, maple and poplar are common hardwoods; southern yellow pine is a common softwood. Freshly sawn boards smell sharply of sap; dried ones barely do.