Used 20ft Shipping Container (Dry): Uses, Modifications and Fit-Out Options

The used 20ft Dry container: versatile and cost-effective equipment

The used 20ft Dry shipping container, also known as a "box" or "standard container", is a staple of international transport and storage. With 33 m³ of internal volume and a Corten steel structure, it offers a robust, modular solution for many projects. This compact format, around 6 metres long, is valued for its manoeuvrability and lower cost compared with a new container. In this article, we explore in detail its uses, possible modifications and fit-out options to make the most of it.

Recap of the technical specifications of the 20ft Dry

Before looking at applications, it is useful to recall the key specifications of this container. Its standard external dimensions are around 6.058 m long, 2.438 m wide and 2.591 m high. Inside, there is around 5.898 m length, 2.352 m width and 2.393 m height, giving a volume of 33 m³. The tare weight is between 2,200 and 2,400 kg, and the maximum payload can reach 28,000 kg. The maximum gross weight (MGW) is commonly 30,480 kg. The structure is Corten steel, corrosion-resistant, with corrugated walls and a 28 mm marine plywood floor. The double rear doors are fitted with container locks and rubber seals. A refurbished used container guaranteed Wind & Watertight (WWT) ensures protection against the weather.

Common uses of the used 20ft Dry container

Static storage

The most widespread use is storing various goods: archives, tools, electronic equipment, furniture, site equipment, etc. Its watertight design and lock (with the option of adding a padlock) provide protection against theft and bad weather. The marine plywood floor supports heavy loads, and the corrugated walls allow shelving or rails to be anchored.

Site office

On construction sites, the 20ft container serves as an office, changing room, break room or storage for materials and tools. It can be fitted with shelving, lighting and ventilation to improve crew comfort.

Modular housing and office

After fit-out, it can be converted into a studio, office, bathroom or kitchen. Its compact volume makes it suitable for small plots, and its robust structure allows several units to be stacked to create multi-level spaces.

Transport and export

For export, it is used to transport goods by sea, road or rail. It can be stacked and handled with suitable lifting equipment (reach stacker, crane, forklift fitted with a spreader).

Possible modifications and fit-outs

Interior fit-out for storage

To optimise space, installing metal shelving or racks saves height and organises references. The corrugated walls offer natural anchor points, but it is best to fix shelving to horizontal rails bolted into the top and bottom rails, so as not to pierce the sheet metal and preserve watertightness. Battery-powered or externally supplied LED lighting improves comfort.

Insulation and interior lining

For use as a site office or living space, adding insulation (mineral wool panels or polyurethane foam) and interior lining (plywood or panelling) helps temper temperature variations. Mechanical or natural ventilation (vents at top and bottom) reduces humidity and renews the air. If the container is to house staff, a side access door or window should be provided, along with an electrical supply compliant with current standards.

Managing condensation

Condensation is common in metal containers, especially when exposed to large day-night temperature swings. To limit this risk, it is advisable to use dehumidifiers (electric or salt-based), install moisture absorbers, or ventilate the container. Another solution is to apply an insulating coating to the inside of the roof, the main condensation point. The marine plywood floor resists moisture, but should not remain in prolonged contact with water.

Exterior customisation

The container can be painted to blend into its environment or for aesthetic reasons. Additional openings (doors, windows) can be cut, but these must be done by a professional to preserve the structure and watertightness. Adding an awning, terrace or staircase is also possible to improve accessibility.

Sector-specific use cases

Agriculture

In agriculture, the 20ft Dry container is used to store seeds, fertiliser, tools and small equipment. It protects inputs from rodents and bad weather.

Construction

In construction, it is used as a site office to store power tools, PPE, spare parts, or as a changing room and break room.

Logistics

Logistics companies see it as a buffer storage solution for pallets and parcels, especially during peak periods.

Local authorities and associations

Local authorities and associations use it to store event equipment, decorations, or as a technical room for road equipment.

Individuals

Finally, individuals use it as self-storage, a DIY workshop or a secure garden shed.

Comparison with other container formats and types

The 20ft container is the smallest standard format in shipping, around 6 m long. The 40ft container measures around 12 m long and offers double the volume (around 67 m³). The 40ft High Cube (HC) adds around 30 cm of internal height, increasing the volume to around 76 m³ and making it easier to store tall loads. The 20ft is more manoeuvrable, easier to move and to place on a cramped plot. It can be transported by standard trucks without an exceptional convoy in most cases, whereas the 40ft often requires a longer container truck. The 20ft is also better suited to stacking on small plots. On the other hand, the 40ft offers a better cost per cubic metre for storing large quantities. The choice therefore depends on the volume to be stored, the space available and transport constraints.

Besides the Dry, there are Reefer containers, insulated and fitted with a refrigeration unit for transporting perishable goods. Open Top containers have a removable roof to load out-of-gauge goods from above. Flat Racks have foldable or absent side walls, for heavy or bulky loads. Tank containers are designed for liquids and gases. Finally, High Cube containers are a taller variant of the standard Dry. The 20ft Dry remains the most versatile and cost-effective for most common needs.

Security and protection against theft

A shipping container offers far better security than a conventional garden shed. Its steel walls and lockable doors deter intruders. To strengthen protection, a high-security padlock (disc lock type) can be fitted to the handles, or an additional door lock added. Some container models are fitted with reinforced locking bars. It is also advisable to park the container in a visible or well-lit place, and to check the condition of the locks regularly. For storing valuables, an alarm or remote monitoring system can be considered.

Foundations and installation

A 20ft container can be placed on flat, stabilised ground, such as a concrete slab, concrete blocks or wooden beams. It is essential that the support is level to avoid any deformation of the structure. If the container is to be stacked, suitable foundations must be provided and safety rules followed. Anchoring to the ground is recommended in wind-exposed areas. For prolonged use, it is advisable to raise the container a few centimetres to allow air to circulate under the floor and prevent moisture build-up.

Planning regulations in France

In France, installing a container on private land may be subject to planning rules. A container used as a storage room may be considered a construction and require prior authorisation (prior declaration of works or building permit) depending on its surface area and how long it is in place. It is recommended to check with the local town hall before any installation. For temporary use on a site, a declaration may also be required. The container must comply with fire safety and accessibility rules if it receives the public.

Transport and handling

The 20ft container is fitted with four corner castings at the corners, which allow it to be lifted and secured. For moving, a container truck with a hydraulic arm (ampliroll) or a forklift fitted with a spreader is required. As the tare weight is around 2.2 to 2.4 tonnes, a forklift of sufficient capacity is required. During transport, the container must be locked onto the truck chassis using twist-locks. It is important to comply with height and width limits on public roads. An exceptional convoy may be necessary if the container is loaded beyond regulatory limits.

Care and maintenance

A used shipping container requires minimal but regular maintenance. It is advisable to clean the roof and gutters to prevent the build-up of leaves and debris, which can retain moisture and encourage rust. Door seals should be cleaned and lubricated (with a silicone-based product) to prevent them drying out and cracking. Locks and hinges should be greased periodically. If rust spots appear, they should be brushed and treated with anti-rust paint. A well-maintained container can last several decades.

Points to check when buying a used container

Buying a used container requires careful examination of its condition. It is advisable to check for rust, particularly on the roof, walls and bottom frame. Surface corrosion is normal and can be treated, but perforating corrosion can compromise watertightness and structural strength. Dents and deformations should also be inspected: they may indicate a violent impact and affect stacking or watertightness. The floor should be examined for rotten areas, splinters or sagging. The doors should open and close without excessive effort, and the seals should be supple and free of cuts. Finally, it is advisable to request a watertightness guarantee (WWT) and to check that the container is delivered with its identification plate (CSC) and identification number (BIC).

Optimising the total cost of ownership of a used container

Beyond the purchase price, the total cost of ownership of a used 20ft container includes several items: delivery and handling, any site preparation, fit-out, routine maintenance and, where applicable, planning permissions. Compared with renting a storage unit, buying often becomes worthwhile as soon as the need is long-term, because the container retains resale value. However, travel costs must be anticipated: a truck with a hydraulic arm or a crane may be necessary if access is difficult, and these services vary depending on distance and site constraints. Providing clear access and stable ground reduces these extra costs. Finally, a well-maintained container can be resold several years later, which offsets the initial investment.

20ft container or conventional storage solution: how to decide

The choice between a shipping container and a traditional shelter (storage unit, warehouse, shed) depends on several criteria. The container offers significantly superior mechanical strength and security, proven watertightness and mobility that allows it to be moved or resold. It is also available quickly and requires no major construction work. On the other hand, it has an industrial look, a fixed floor area (around 14 m² usable) and humidity management to monitor. A permanent structure blends better with existing buildings and can be insulated more easily, but it generally costs more to build and is not movable. For a temporary need, a site, secure storage or an evolving project, the used container is often the most pragmatic solution.

Conclusion

The used 20ft Dry shipping container is a durable and functional investment. Its robust design, watertightness and modularity make it suitable for many projects. By taking care to inspect it before purchase and maintain it regularly, you will benefit from secure, cost-effective storage space for many years. Whether you are a building professional, a farmer, a logistics specialist or an individual, this container will meet your needs reliably.