Dunnage is the inexpensive material—wood, foam, airbags, plastic, or corrugated board—placed inside a container, trailer, or pallet to brace cargo, absorb shock, and keep freight from shifting in transit. Good dunnage prevents in-transit damage, load shift, and moisture problems, which is why carriers and warehouses treat it as a core part of safe loading rather than an afterthought.
What does dunnage actually do?
When a truck brakes, a container rolls in heavy seas, or a forklift sets a pallet down hard, unsecured freight moves. Dunnage fills the empty space (called “void space”) so cargo stays put. It also lifts product off the floor to avoid water damage, separates incompatible items, and distributes weight so boxes on the bottom of a stack are not crushed. The result is fewer damage claims, safer handling, and cargo that arrives in the same condition it left.
Common types of dunnage
Wood dunnage
Lumber, plywood, and blocking are the classic choice for heavy or oddly shaped freight—machinery, steel, and oversize equipment. Wood is strong and reusable but must be heat-treated (ISPM 15 stamped) for international shipments to prevent the spread of pests.
Air bags (dunnage bags)
Inflatable paper or polywoven bags wedge into the gaps between pallets inside a trailer or container. They are fast to deploy, lightweight, and ideal for stabilizing palletized freight.
Foam and molded inserts
Custom foam cushions fragile or high-value items such as electronics and medical devices, absorbing vibration and impact.
Corrugated and plastic dunnage
Corrugated sheets, edge protectors, and reusable plastic trays are common in e-commerce and returnable-packaging programs where cost and recyclability matter.
Dunnage in the warehouse and at the dock
Loading freight well is where dunnage pays off. Teams that cross-dock, transload, or palletize before line-haul build dunnage into the load plan so trailers ship full, braced, and balanced. At Go Freight’s bonded Miami warehouse, blocking and bracing is part of standard outbound handling, so containers leaving PortMiami and Port Everglades are loaded to survive the trip rather than just to fill space.
How much dunnage do you need?
The right amount depends on cargo weight, fragility, mode, and how much void space the load leaves. A dense steel coil needs heavy timber and chains; a pallet of cartons may only need a single dunnage bag and corner boards. Over-bracing wastes money and cubic capacity; under-bracing invites damage claims. Experienced loaders aim for the minimum that fully immobilizes the freight.
Frequently asked questions
Is dunnage the same as packaging?
No. Packaging protects an individual product (the box, the shrink wrap). Dunnage protects and secures the load as a whole inside the trailer, container, or on the pallet during transport.
Does dunnage count toward my shipment weight?
Yes—wood blocking and other materials add tare weight, which can matter for over-the-road weight limits and freight charges. Lightweight options like air bags minimize that impact.
Do I need special dunnage for international ocean freight?
Any solid wood dunnage crossing borders must be ISPM 15 heat-treated and stamped. Using non-compliant wood can lead to fumigation, fines, or refused entry.
Ship freight that arrives undamaged
Proper dunnage, smart load planning, and asset-based handling keep claims low and deliveries on time. Request a quote or call Go Freight at (786) 445-0150 to move your freight through Miami with bracing and warehousing handled end to end.