Complete Buying Guide: How to Choose a Used 20-Foot Shipping Container (Dry)

Why choose a used 20-foot shipping container?

The used 20-foot Dry shipping container has become an essential solution for storage and transport of goods. Its popularity rests on a rare balance between sturdiness, modularity, and controlled cost. Unlike new, a refurbished used container provides access to quality industrial equipment at a significantly lower price, while retaining the essential characteristics that make this type of container so reputable.

Choosing a used container is also a rational environmental choice. By extending the life of an already manufactured container, you avoid producing a new good and reduce the associated carbon footprint. This circular economy approach appeals to more and more companies and individuals seeking to combine performance and responsibility.

But how do you choose the right used 20-foot container among the many available offers? This guide takes you step by step, from understanding technical specifications to the checks to perform before purchase, including sector-specific uses and installation tips.

Anatomy of a 20-foot Dry container: what you need to know

Structure and materials

The 20-foot Dry container is built around a Corten steel frame, a low-alloy steel that resists corrosion better than ordinary steel thanks to the formation of a protective oxide layer on the surface. The side walls, roof, and front faces are made of corrugated sheets, welded to a rigid frame. This design gives the whole a high mechanical strength, capable of withstanding the stresses of stacking and port handling.

The floor is made of 28 mm marine plywood, a dense material treated to resist moisture and rolling loads. It rests on metal cross members that distribute the weight. The rear face is equipped with double doors, with checked sealing gaskets and container locks (locking bars and handles) in good working order.

Dimensions and volumes

The standard 20-foot container has an external length of about 6.058 m, a width of 2.438 m, and a height of 2.591 m. Typical internal dimensions are about 5.898 m long, 2.352 m wide, and 2.393 m high, offering an internal volume of about 33 m³. The usable floor area is around 13.8 m².

The tare weight is generally around 2,200 to 2,400 kg depending on the manufacturer, and the maximum payload can reach about 28,000 kg, for a maximum gross weight (MGW) of 30,480 kg. These values are indicative and may vary slightly from one container to another; they are shown on the CSC plate attached to the door.

Certifications and compliance

A shipping container must meet ISO 668 and ISO 1496 standards, which define its dimensions and strength. The CSC plate (Convention for Safe Containers) certifies that the container has been inspected and found compliant with international safety rules. For export, a valid CSC plate is essential. Always check its presence and legibility before purchase.

Selection criteria for a used 20-foot container

General condition and structure

The condition of the structure is the first criterion to examine. Look for perforating rust, major deformations on walls or roof, cracked welds. A used container may show superficial wear marks, but these must not compromise the integrity of the whole. Corners and edges are particularly sensitive to impacts; inspect them carefully.

Watertightness

Watertightness is the guarantee of effective protection against rain, dust, and moisture. A container described as "Wind & Watertight" has been tested to resist wind and water. Check that the door gaskets are supple, without cuts or cracks, and that the locks close properly. A simple test is to slide a sheet of paper between the gasket and the door: if it slides easily, the seal is not perfect. Also inspect the roof and walls for holes or cracks.

Floor

The marine plywood floor must be examined carefully. Soft, delaminated areas or traces of moisture may indicate water infiltration. A sound floor is dense and homogeneous. If in doubt, do not hesitate to walk over the entire surface to detect weaknesses.

Doors and locks

The doors must open and close without excessive effort. Hinges and locks must be lubricated and work properly. Doors that rub or do not align may indicate structural deformation. Also check the presence and condition of locking bars and handles.

CSC plate and history

The CSC plate must be present and valid for international maritime transport. It indicates the manufacturing date, country of origin, tare weight, payload, and date of last inspection. The container's history (previous use, number of voyages) can give indications of its condition, but does not replace a careful visual examination.

Uses of a used 20-foot Dry container

Static storage

Static storage is the most common use. Construction equipment, tools, archives, various goods, agricultural or industrial equipment: the 20-foot container offers a secure and watertight space. Its lockable door and rigid structure limit the risk of theft and damage. On a construction site, it frequently serves as a technical room or storage store for tools and consumables.

Transport and export

In logistics, the 20-foot container remains a reliable shipping support for maritime, rail, or road transport, especially for exporting palletized goods. Its compact size facilitates passage on container trucks and standard trailers, without requiring special oversized load permits in most cases.

Light conversion

The 20-foot Dry container can be converted into a site office, secure storage room, workshop, or even basic living quarters. This conversion, however, requires specific work: insulation, electricity, ventilation, sometimes opening bays. It is important to note that an unmodified used container is not designed for permanent habitation without suitable conversion, particularly due to possible condensation and the lack of sufficient natural ventilation.

Sector-specific uses

In the building and public works sector, it is commonly used as a site store to store sensitive tools, PPE, spare parts, or consumables. Some companies install a workbench and lighting to create a mobile workshop. In agriculture, it is used to store seeds, fertilizers, small equipment, or crops sensitive to moisture. Winegrowers and producers see it as a solution for storing bottles, crates, and cellar equipment, provided correct ventilation is planned. In commerce and distribution, it becomes a seasonal storage reserve or an order preparation room. Finally, individuals use it to free up a garage, store furniture, archives, light vehicles (motorcycle, quad, small equipment), or leisure equipment.

Comparison with other container types

To choose well, it is useful to compare the 20-foot Dry with other sizes and types of containers. The 40-foot Dry offers about 67 m³ and an internal length of around 12 m; it suits large volumes and group shipments, but it is heavier, bulkier, and requires a larger floor area. The 40-foot High Cube gains about 30 cm of internal height, which is appreciable for storing bulky goods or for conversion. The 10-foot, rarer, is suitable for small spaces but offers limited volume. The 20-foot High Cube combines the length of the 20-foot and the extra height of the High Cube: it is interesting for tall loads. Open Top containers are designed to load goods from above, while Flat Racks have no side walls for out-of-gauge loads. Reefer containers are equipped with a refrigeration unit for transporting perishable goods; they are heavier and more expensive, and their use for static storage is less common. Finally, the new container offers superior watertightness and aesthetics, but at a significantly higher price; the used, refurbished and checked container offers an interesting value for money for many applications.

Points to watch before purchase

Before confirming an order, several checks are essential. Ask for recent photos of the container, especially of the corners, roof, floor, and doors. If possible, make an on-site visit to see the actual condition. For export use, check that the container is indeed ISO 20-foot type and that its CSC plate is legible. For storage use, the absence of holes and through-corroded areas is essential. Finally, compare several offers to gauge the price and choose a container suited to your needs, without overpaying for unnecessary options.

Delivery and setup

A 20-foot container is transported on a container truck equipped with a hydraulic arm or a high-capacity forklift. Delivery requires sufficient road access, maneuvering space for the truck, and a flat drop-off area. When access is difficult, it may be necessary to plan a transfer to a smaller truck or the use of a mobile crane. These operations must be anticipated with the carrier to avoid additional costs and downtime. Once placed, the container must be shimmed and checked: opening and closing the doors must remain easy, indicating that the structure is not constrained.

Ground preparation

A loaded 20-foot container can weigh several tons; it is therefore essential to provide stable and horizontal support. Concrete blocks, hardwood beams, or distribution slabs are commonly used. Soft or sloping ground can cause structural deformation and difficulty closing the doors. Accessibility for the delivery truck and the clearance needed to maneuver the double door must also be considered. If the container is to remain in place, periodic checking of flatness and absence of corrosion at the bottom rails is recommended.

Maintenance and longevity

Maintaining a used 20-foot container is simple but regular. Visually check the condition of the paint and door gaskets at least once a year. Rubber gaskets can harden or crack over time; their replacement is inexpensive and preserves watertightness. The marine plywood floor must be kept clean and dry; in case of oil or chemical stains, quick cleaning prevents impregnation. Hinges and locks must be lubricated periodically to facilitate operation. Finally, if the container is stored outdoors, slightly raising it on blocks or beams avoids direct contact with the ground and limits corrosion of the base.

Regarding lifespan, a well-maintained used container can remain watertight for many years, especially if used for static storage and not subjected to repeated cycles of maritime transport. The main aging factors are corrosion, mechanical impacts, and prolonged exposure to salt or moisture. By the sea, rinsing with fresh water and more frequent paint checks are recommended. In industrial areas, particle-laden air can also accelerate soiling; periodic cleaning is usually sufficient.

Security and regulations

A closed container is a difficult space to penetrate, but it is not inviolable. Adding a quality padlock, or even a reinforced locking system, improves protection. For sensitive storage, a standalone alarm or lighting with detection can complement the system. It is also advisable not to store chemicals incompatible with steel or wood without precautions, and to follow the storage rules specific to each product.

Regarding transport regulations in France, a standard 20-foot container complies with the maximum dimensions allowed for heavy goods vehicles without special exemption. Its road transport is therefore possible with a suitable container truck, subject to compliance with the authorized gross vehicle weight. For export, the container must comply with ISO standards and have a valid CSC plate. If the container is used as a site office, it may be subject to local planning rules, especially if its placement exceeds a certain duration or if it is visible from the public road. It is advisable to check with the town hall before any permanent installation.

Thermal insulation: what to plan for

An uninsulated container is strongly affected by temperature variations: it can become very hot in summer and cold in winter. For storing sensitive materials, insulation with rigid panels or spray foam can be considered. For office or workshop use, full insulation with ventilation and heating is necessary. These conversions must be carried out in compliance with safety rules, particularly electrical ones.

Conclusion

The used 20-foot Dry shipping container is a sturdy, standardized, and versatile product. It is suitable for both temporary or permanent storage and for transporting goods, and can serve as a base for light conversions. Its Corten steel, 28 mm marine plywood floor, and doors equipped with checked gaskets make it a rational investment for professionals and individuals alike. Before purchase, careful checking of structural condition and watertightness remains the key to fully enjoying its longevity.