Used 40ft Shipping Container (Dry): Uses, Modifications and Fit-Out Options

The used 40ft Dry container: a standardised box with many advantages

The used 40ft Dry shipping container, often called a 40' DC, is a metal box originally designed for intermodal freight transport. Today it is widely reused as fixed storage space or as a base for fit-out. Its standardised dimensions (about 12.19 m long, 2.44 m wide, 2.59 m high) and internal volume of around 67 m³ make it the largest common standard format, just behind the 40ft High Cube, which adds about 30 cm in height. The model offered here is a standard Dry, meaning no insulation or refrigeration, with double rear doors and a 28 mm marine plywood floor.

The structure is built on a Corten steel frame, a low-alloy steel that resists atmospheric corrosion better than ordinary steel thanks to the formation of a protective oxide layer on the surface. The walls, roof and doors are made of corrugated sheet, which increases rigidity without making the whole unit excessively heavy. The floor, laid on metal crossbeams, supports forklift traffic and allows pallets, machinery or heavy goods to be placed on it, within the maximum permitted load. Access is via double rear doors fitted with container locks (vertical bars and handles) that lock both leaves at several points. These doors have rubber seals which, when the locks are properly tightened, provide protection against rain, wind and dust. The container complies with the ISO standard, ensuring dimensions and fixing points compatible with standard lifting and transport equipment (spreader, twist-locks, carrying trucks).

This container is offered used, in cement-quality grade, with air/water tightness and a sturdy floor suitable for forklift traffic. It therefore shows signs of use (scratches, minor dents, surface rust) without this compromising its primary function: protecting goods from weather and intrusion.

Why choose a 40ft rather than another format?

The 40ft Dry stands out for its volume twice that of a 20ft (about 67 m³ versus 33 m³) for double the length, but identical width and height. The 20ft remains more manoeuvrable and can be transported on a standard truck without excessive overhang, making it practical for sites with difficult access. The 40ft offers a better volume-to-price ratio per cubic metre. The 40ft High Cube adds height (about 2.69 m internal height) and is suitable for bulky but light loads, such as cartons, textiles or packaging. The 45ft, less common, is mainly used on certain corridors and remains rare on the used market in France. Finally, specialised containers (reefer, open top, flat rack, tank) meet specific needs: the reefer for temperature-controlled transport, the open top for loading out-of-gauge objects from above, the flat rack for heavy and wide loads without walls, the tank for liquids. For standard storage use, the 40ft standard Dry represents the best compromise between capacity, price and simplicity.

Practical uses of the used 40ft Dry container

Professional and industrial storage

In construction and public works, the 40ft Dry serves as a site office or site store: power tools, consumables, PPE and spare parts are stored there, and an office or break room can be installed after fit-out. In industry and logistics, it acts as a buffer storage for pallets, spare parts or customer returns, and can be fitted with metal shelving to optimise height. In retail, it becomes seasonal storage or an order preparation room. For events, it can serve as a technical room, control room or temporary changing room.

Agricultural storage

In farming, a 40ft Dry serves as a storage shed for grain, hay, fertiliser or equipment, provided sufficient ventilation is included to prevent condensation. It can also hold animal feed, seeds, plant protection products (with ventilation and safety precautions), small equipment and harvests. Its length allows long objects (tubes, profiles, planks) to be stored, and its free height of about 2.39 metres allows multi-level pallet storage, provided suitable lifting equipment is available.

Private use

For an individual, it can house a vehicle, garden furniture, firewood or leisure equipment. It is a better alternative to a garden shed or garage, with a much longer lifespan and greater security against theft. In all these cases, the load-bearing capacity of the ground must be checked: a loaded 40ft container can weigh more than 30 tonnes in total, requiring stable ground, ideally a concrete slab or compacted soil, and correct load distribution on the longitudinal beams.

Possible modifications and fit-outs

Beyond pure storage, the shipping container is increasingly used as a base for fit-out: site office, technical room, changing room, workshop, break room, or even modular housing or extension. These projects, however, require specific work.

Thermal insulation and ventilation

A bare container is neither insulated nor ventilated: without fit-out, it can be very hot in summer and cold in winter, and prone to condensation. For habitable or prolonged work use, suitable insulation and ventilation must be provided. Insulation can be done internally with rigid panels (polyurethane, extruded polystyrene) or externally with an added frame. Natural ventilation (low and high grilles) reduces condensation, particularly for storing moisture-sensitive materials. Mechanical ventilation can be added for controlled air renewal.

Electricity and plumbing

The electrical installation must be carried out to professional standards, with conduits and junction boxes suitable for a metal environment. It is recommended to provide a consumer unit, sockets, and internal and external lighting. For plumbing, if the container is intended for sanitary use, a water supply, drainage and frost protection must be provided. This work requires qualified professionals.

Openings and joinery

Adding extra windows and doors is possible, but requires cutting the walls and reinforcing the structure. Any cut weakens the overall rigidity: it is essential to provide metal reinforcements (angle irons, tubes) around the openings. The joinery must be suited to the wall thickness and properly sealed to prevent infiltration.

Interior fit-out

Interior fit-out can include partitions, floor coverings (parquet, tiles, resin), ceilings, paint and sanitary facilities. The original wooden floor can be kept or covered. For office or residential use, high-performance sound and thermal insulation is advisable. The internal height of 2.39 m allows a comfortable space to be created, but the thickness of insulation and coverings must be taken into account.

Key checks before buying a used container

Buying a used container deserves some checks. The first concerns the general condition of the structure: look for major dents, perforations, areas of deep rust (especially on the roof, lower walls and floor). Surface rust is normal and can be treated; perforating rust indicates structural weakness. Then check watertightness: with doors closed and locks tightened, no light should pass between the seals and the frame. The floor must be sound, with no soft or rotten areas; a damaged floor can be repaired or replaced, but this represents a cost. Check the door locks: they must operate without forcing and keep the leaves pressed shut. Also examine the lifting corners and fixing rails, used for lifting and securing: they must be intact. Finally, ask whether the container is "cargo worthy" (suitable for sea transport) or simply "wind and watertight". A cargo worthy container has passed an inspection and can go back to sea; a wind and watertight container is watertight but no longer necessarily certified for transport. For storage use, a wind and watertight one is generally sufficient, and its price is lower. The model offered is described as cement-quality grade, i.e. a used container that has seen service, with air/water tightness and a sturdy floor suitable for forklift traffic.

Transport and installation

Transporting a 40ft container in France and Europe is subject to precise rules. A 40ft weighs about 3.7 to 4 tonnes empty depending on the model, and can carry a payload of around 26 to 28 tonnes in sea transport, but road limits are different. In France, a standard semi-trailer truck is limited to 44 tonnes gross combined weight (PTRA) under combined transport, and 40 tonnes for conventional road transport, unless exemptions apply. The 40ft container is transported on a suitable container chassis, with twist-locks at the four corners. Delivery on site often requires a crane truck or mobile crane to unload, as a loaded container cannot be handled without lifting equipment. The length of the 40ft (about 12.19 m) means access must be checked: street width, overhead cables, slope, gate, manoeuvring yard. A 20ft is sometimes preferred for sites with difficult access, but the 40ft offers a better volume-to-price ratio per cubic metre.

Installation must comply with local planning rules: depending on the municipality, a container placed on the ground without foundations and used temporarily may be exempt from formalities; but as soon as it is fixed, connected to utilities or used permanently as housing or a workplace, it may be treated as a construction and subject to prior declaration or building permit. It is therefore essential to consult the municipality's local urban plan (PLU) and, if necessary, contact the planning department.

Maintenance and durability

Maintaining a shipping container is relatively simple but regular. The roof and gutters must be cleaned to avoid the accumulation of leaves and stagnant water, which accelerates corrosion. Rusty areas should be brushed and then treated with a rust-inhibiting paint suitable for steel. Door seals must be checked and possibly lubricated or replaced if cracked. Locks and hinges should be greased once or twice a year. The wooden floor can be treated against moisture and insects, especially if exposed outdoors. If the container is placed on the ground, it is advisable to raise it slightly on blocks or beams to avoid direct contact with ground moisture and to facilitate ventilation under the floor. Natural ventilation (low and high grilles) reduces condensation, particularly for storing moisture-sensitive materials. Finally, a container placed on land must comply with local planning rules.

Regulations and safety

Regarding transport, the container must be secured in accordance with the Highway Code and safety recommendations, with twist-locks checked before departure. The total weight of the vehicle, chassis and loaded container must remain within permitted limits, otherwise fines and immobilisation may apply. For exceptional transport, prior authorisation may be required. Customs-wise, a container used for international transport must have a valid CSC plate (Convention for Safe Containers), certifying its safety compliance; this plate is affixed to the door or side wall and must be legible. For purely private storage use, this requirement does not apply, but it remains a good indicator of the container's quality and history.

Practical tips to get the most out of your container

Before loading it, plan how to organise the space: heavy objects on the floor and in the centre, light objects high up, fragile items protected from moisture. Use pallets or beams to isolate goods from the floor and facilitate handling. If possible, install interior lighting and a socket, even a basic one, to work comfortably. If the container remains exposed to the sun, a light-coloured roof paint reduces the internal temperature. Finally, keep a copy of the technical specifications and the CSC plate if present, useful in case of resale or inspection. With these precautions, the used 40ft Dry container is a durable and adaptable investment, suitable for many professional and personal projects.