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

Why choose a used 20ft Dry shipping container?

The used 20ft Dry shipping container, often called a "20ft standard", is a Corten steel box originally designed to carry dry goods on ships. Today it enjoys a highly sought-after second life: storage, technical room, workshop, site office or even a base for a lightweight home. Its low price, robustness and standardised dimensions make it a credible alternative to traditional construction. At Transport Hosni Conteneur in Marseille, this model is supplied refurbished and guaranteed Wind & Watertight, meaning it is watertight and windproof, ready for immediate use.

But before buying, it is essential to understand what this container can really do, how to fit it out and what precautions to take. This article details concrete uses, feasible modifications, regulatory constraints and good maintenance practices.

Technical specifications of the 20ft Dry container

Dimensions and volume

A 20ft Dry container complies with ISO 668. Its external dimensions are approximately 6.058 m long, 2.438 m wide and 2.591 m high. Inside, the usable volume is around 33 m³, with a floor area of about 13.8 m². These standardised dimensions allow it to be stacked, piled and transported on any suitable ship, train or truck. The maximum payload is around 28 tonnes, but it depends on the container's exact tare weight, generally between 2.2 and 2.4 tonnes.

The floor is 28 mm marine plywood, fixed to metal cross members welded to the frame. The walls and roof are corrugated Corten steel, a self-weathering steel that develops a protective oxide layer slowing corrosion. The rear doors are double doors fitted with locking bars and rubber seals. These seals are checked during refurbishment: they must remain flexible and tear-free to ensure watertightness.

Used condition and Wind & Watertight guarantee

A used container has already sailed. It may show superficial rust, scratches or minor impacts. However, a refurbished container guaranteed Wind & Watertight has been checked to ensure its structure withstands driving rain and sea spray. This guarantee does not mean it is new, but that it is watertight and structurally sound for storage or transport use. The CSC plate (Convention for Safe Containers) must be legible and valid if you plan to use it for export.

Main uses of a used 20ft container

Static storage: the most common solution

Storage is the number one use. On private land, a building site, a company car park or an industrial zone, the 20ft container provides secure space for equipment, tools, spare parts, archives or seasonal goods. It can be locked with a padlock (not supplied) and remains accessible at any time. Its resistance to weather and rodents makes it a reliable shelter, unlike a simple wooden shed.

For an individual, it is a better option than an overflowing garage or a paid storage unit. For a business, it is a quick-to-install storage extension, with no masonry work.

Transport and export

After refurbishment, a used 20ft Dry container can go back to sea to carry goods. This requires a valid CSC plate and suitable structural condition. Transport can be by container truck, train or ship. In France, the total weight (container plus load) must not exceed the vehicle's legal limits, i.e. 44 tonnes for a standard road combination. Lifting must always be done using the four corner castings with spreaders or suitable slings. Never lift a container by its walls or roof.

Technical room, workshop, site office

The 20ft container is frequently converted into a technical room, workshop, changing room or site office. Its rigid structure and standard dimensions make it easy to install openings (doors, windows), partitions, insulation and electrical systems. In construction, it serves as a site store for tools, PPE and consumables. It can be fitted with shelving, a workbench and lighting. In events, it becomes a control room, changing room or storage for stage equipment.

Agriculture, retail and logistics

In agriculture, it houses seeds, fertilisers, small equipment or crops sensitive to humidity. In retail and logistics, it acts as seasonal storage extension or order preparation area. In the maritime and port sector, it is a tool for transport and temporary storage on terminals. For individuals, it can become a motorcycle garage, DIY workshop or gardening store.

Energy and telecoms

In energy and telecoms, the 20ft container can house generators, batteries or technical equipment. Note: these uses require suitable ventilation and sometimes liquid retention. Each use imposes its own specific constraints.

Possible modifications and fit-outs

Thermal and acoustic insulation

To convert a container into an office, workshop or living space, insulation is often the first step. Several solutions exist: rigid insulation panels (polyurethane, extruded polystyrene), mineral wool with vapour barrier, or spray foam. Insulation must be installed leaving a gap to avoid condensation between the insulation and the metal wall. A vapour barrier is recommended to limit thermal bridges. For office use, acoustic insulation can be added to reduce outside noise.

Openings: doors, windows, ventilation

Adding extra windows and doors is common. The sheet metal must be cut carefully, frames reinforced and perfect sealing ensured. Ventilation is essential: without it, condensation can build up and cause rust or mould. Passive ventilation (protected vents) or active ventilation (MVHR) can be installed. For an office, an opening window is often necessary.

Electricity and lighting

An electrical installation compliant with current standards is essential for professional use. You need a distribution board, sockets, suitable lighting and earthing. Cables must be mechanically protected and moisture-resistant. For a work room, lighting must be sufficient and emergency exits respected.

Partitions and interior fit-out

Lightweight partitions (metal frame + plasterboard or particle board) allow the space to be divided into several rooms: office, sanitary facilities, storage. The existing marine plywood floor can be covered with a finish (PVC, tiles, carpet) depending on use. For a dwelling, the rules are stricter: building permit, compliance, drainage. It is advisable to use professionals for major conversions.

Roof and sun protection

A container exposed to the sun can become an oven. Adding a secondary roof (ventilated over-roof) or reflective paint reduces the interior temperature. Roof insulation is also effective. For outdoor use, protection against rain and run-off is recommended.

Regulations and planning

Permits and prior declaration

In France, placing a container on private land may be considered a construction if it is fixed to the ground and intended to last. In that case, a prior works declaration or a building permit may be required, depending on the surface area and the nature of the project. Rules vary by municipality and zone (urban, agricultural, protected). It is essential to check with the local planning department before any permanent installation. For temporary use (site), authorisation may also be required if the container remains in place for more than a few months.

Health and safety at work

If the container is used as a work room, it must comply with health and safety rules: ventilation, lighting, emergency exits, etc. Even for a temporary installation, these rules apply. It is advisable to consult a professional to verify compliance.

CSC plate and transport

For international sea or land transport, the CSC plate must be valid. This international convention requires every container to carry a plate showing its date of manufacture, maximum load, tare and periodic inspection dates. For static storage use, regulations are less strict, but a container with a degraded structure can present a risk.

What to check before buying

Structural inspection

Check for perforating corrosion on the walls, roof or frame. Superficial rust is normal and can be treated, but holes or heavily thinned areas compromise watertightness and strength. Inspect welds and corner castings: they can accumulate dirt and moisture.

Floor and doors

Make sure the floor is not rotten, warped or infested. A sound floor should be hard, with no soft spots, and properly screwed to the cross members. Doors must open and close without forcing, and seals must be intact. A simple test is to close the doors and check that no light passes between the seals and the frame.

CSC plate and history

The CSC plate must be legible and valid for transport use. Ask for detailed photos of the corners, roof, floor and doors. If possible, visit the container before buying. A reliable seller such as Transport Hosni Conteneur provides accurate information on the container's condition and history.

Care and maintenance

Annual inspection

Visually inspect the structure at least once a year, paying particular attention to areas exposed to moisture: lower walls, corners, door surrounds. Remove dirt and debris from the roof to prevent water pooling. If paint flakes appear, touch up with a suitable anti-rust paint.

Moisture protection

Do not let water pool around the base. If the container is placed directly on the ground, moisture can rise by capillary action into the floor and frame. It is better to place it on blocks, treated timber cross members or concrete slabs, to create a ventilated air gap under the floor. Inside, ventilate regularly to avoid condensation. Adding a moisture absorber or passive ventilation can help.

Seal and door maintenance

Door seals can be cleaned and possibly treated with a rubber care product to prolong their flexibility. Never obstruct the seals with objects that could deform them. Regularly check that the locks work properly.

Comparison with other containers

20ft vs 40ft

The standard 40ft container offers double the volume (about 67 m³) for a floor area of about 28 m². It is better suited to bulk storage or transporting large volumes, but it is heavier, bulkier and requires a larger site. The 20ft is more practical for deliveries in city centres or on sites with limited access, as it can be handled by crane trucks or medium-capacity forklifts.

20ft vs 10ft

The 10ft container, rarer, is compact and fits into tight spaces, but its volume is limited (about 16 m³). It is suited to small storage or projects with very tight space constraints.

20ft Dry vs High Cube

The 40ft High Cube (HC) container adds about 30 cm of interior height, which is useful for storing tall loads or creating a living space with a better sense of volume. The 20ft Dry remains the most versatile and economical for everyday use.

20ft Dry vs Open Top, Flat Rack, Reefer

The Open Top container has an opening or removable roof, handy for loading bulky items from above. The Flat Rack, with no side walls or roof, is designed for out-of-gauge loads. The Reefer is a refrigerated container, intended for perishable goods; it is more expensive and requires a power supply. The 20ft Dry remains the most versatile and easiest to resell.

Preparation before use

Cleaning and deodorising

If you plan to store sensitive items, a full clean is necessary: sweeping, possible washing, drying. Check that the floor does not give off odours (containers that have carried odorous products can retain smells). A coat of paint on the floor can help protect it and make cleaning easier.

Interior fit-out

For office use, ventilation, lighting and a power supply are required. These fit-outs must comply with current electrical standards. For dwelling use, the rules are stricter (building permit, compliance, drainage). It is advisable to use professionals for major conversions.

Conclusion

The used 20ft Dry shipping container is a rational investment for many professionals and individuals. Its low price, robustness and modularity make it a versatile solution for storage, transport or conversion into a technical room, site office or workshop. With minimal maintenance, it can serve for many years. At Transport Hosni Conteneur in Marseille, this model is supplied refurbished and guaranteed Wind & Watertight, with delivery available throughout France. For any questions about availability, delivery options or accessories, it is advisable to contact the company directly.