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

Why choose a used 20-foot Dry shipping container?

The used 20-foot Dry shipping container is a standardized, robust, and modular piece of equipment, widely used for storage, transport, and conversion. Its popularity stems from an attractive volume-to-price ratio, high availability on the second-hand market, and universal compatibility with handling infrastructure. Before buying, it is essential to understand its characteristics, limitations, and the criteria that distinguish a quality refurbished container from one that has simply been resold.

This guide takes you step by step: technical definition, dimensions, materials, inspection points, uses, regulations, transport, maintenance, and buying tips. The goal is to enable you to make an informed choice suited to your needs and budget.

What is a 20-foot Dry container?

A 20-foot Dry container is an ISO container designed for transporting and storing dry goods. It has no refrigeration system or active ventilation. Its one-piece Corten steel structure and 28 mm marine plywood floor give it high mechanical strength and good weather resistance.

It is equipped with double rear doors with container locks and rubber seals. These seals are wear parts: their condition determines air and water tightness. A refurbished used container must have supple seals, free of cracks or tears, and functional locking mechanisms.

Main technical specifications

• Type: Dry shipping container
• Nominal length: 20 feet (approx. 6.06 m)
• External dimensions (L x W x H): approx. 6.06 m x 2.44 m x 2.59 m (ISO 668 standard)
• Internal dimensions (L x W x H): approx. 5.90 m x 2.35 m x 2.39 m
• Internal volume: approx. 33 m³
• Structure material: Corten steel
• Floor: 28 mm marine plywood
• Doors: double rear doors with container locks
• Door seals: rubber, checked for tightness
• Certification: ISO
• Condition: refurbished used, Wind & Watertight guarantee
• Tare weight: approx. 2,200 to 2,400 kg depending on manufacturer
• Maximum payload: approx. 28,000 kg (depending on tare weight and limitations)
• Corner fittings: 4 top and 4 bottom ISO standard corner castings
• Use: storage, construction site, export, conversion

Inspection points before purchase

Buying a used container requires careful examination. Not all sellers perform the same checks, and the actual condition can vary considerably from one unit to another. Here are the points you must check.

Structure and tightness

Inspect the walls, roof, and floor. Look for holes, major deformations, perforating rust, or non-compliant repairs. The doors must open and close without forcing. The seals must be supple, complete, and free of cracks. The locks must work properly. A visual test or a water test can reveal leaks. The Wind & Watertight guarantee announced by the seller must be specified contractually (duration, scope).

Floor and wear parts

The 28 mm marine plywood floor must not show rotten areas, delamination, or holes. Check the steel cross members under the floor. Door seals and locking mechanisms are wear parts: they can be replaced, but their initial condition gives an indication of the container's overall maintenance.

Marking and compliance

Ask for the CSC (Convention for Safe Containers) marking and identification plates. For international transport use, these are mandatory. For static use, they remain an indicator of quality and traceability. Check the serial number and the container's origin: a container that has carried chemicals or foodstuffs may require specific cleaning.

Uses of a used 20-foot Dry container

Its versatility makes it suitable for many contexts. Here are the main uses.

Static storage

Securing equipment, archives, tools, furniture, or various goods. Its closed, lockable design provides protection against bad weather and a deterrent physical barrier.

Construction site

Technical room, tool store, changing room, or break room. Check the applicable safety and layout rules (ventilation, lighting, exits).

Export

Standardized means of transport, compatible with container ships, trains, and trucks. The container must comply with the CSC convention and carry a valid approval plate.

Conversion

Transformation into a site office, fitted storage room, or modular housing base. These conversions must comply with current construction, insulation, and safety rules. Ventilation is recommended if the container is occupied or stores moisture-sensitive products.

Comparison with other formats

The choice of a container depends on the required volume, available space, and budget. Here is how the 20-foot compares to other common formats.

20-foot vs 40-foot

The 20-foot is more maneuverable, easier to transport and place on tight sites. It weighs less empty and can be moved by more common machinery. However, it offers about half the volume of a 40-foot, which may require multiple units for large needs.

20-foot vs 10-foot

The 20-foot offers significantly more volume while remaining transportable on a standard truck. The 10-foot is often used for very constrained spaces.

20-foot vs High Cube

The 20-foot High Cube offers about 30 cm more internal height, useful for taller volumes or conversion. It is less common on the used market and may be more expensive.

20-foot vs Open Top, Flat Rack, Reefer

The Open Top container, without a rigid roof, facilitates top loading of tall or heavy items. The Flat Rack, without side walls, is suitable for out-of-gauge loads. The Reefer is equipped with a refrigeration unit and intended for perishable goods; it is heavier, more expensive, and requires a power supply. The 20-foot Dry remains the most standard and economical choice for storing and transporting dry goods.

Transport and handling

Transporting and handling a 20-foot container requires suitable machinery. A truck with an auxiliary crane, a forklift with sufficient capacity, or a reach stacker can be used. The lifting points are the four top and bottom corners, equipped with standardized corner castings. It is essential never to lift a container by its walls or roof.

The total weight (container plus cargo) must comply with French road limits. In France, road freight transport is governed by the Highway Code and regulations on weights and dimensions. For a 20-foot container, the authorized gross vehicle weight depends on the vehicle and trailer type. Exceptional transport may be necessary if dimensions or weight exceed regulatory thresholds. It is recommended to use a specialized carrier and check the necessary permits.

Installation and conversion

Ground installation must be carefully planned. A container can be placed on concrete blocks, hardwood beams, or slabs to avoid direct contact with the ground and limit humidity. A slight slope can help with water drainage. If the container is to remain in place, anchors can be provided to resist wind, especially in exposed areas.

For housing or office use, insulation, ventilation, electricity, and interior fitting must be considered, complying with construction and safety standards. These conversions may require planning permission depending on the intended use and duration. The electrical installation, if any, must comply with NF C 15-100.

Applicable regulations

Regulations depend on the use. For maritime transport, the container must comply with the CSC convention and carry a valid approval plate; periodic inspections (ACEP) are mandatory for containers used in international transport. For road transport in France, the container is considered as goods or as a vehicle accessory depending on the case. The authorized gross vehicle weight (PTRA) and the vehicle's payload must be respected, as well as the maximum authorized dimensions (width 2.55 m, height 4 m, length 16.50 m for a road train, subject to regulatory changes).

A loaded 20-foot container may exceed the weight limits of some light vehicles; therefore, the payload of the truck and trailer must be checked. Exceptional transport is required when thresholds are exceeded, with prior authorization and a defined route. For static use, the rules fall under urban planning: installation may require a prior declaration or a building permit depending on the surface area, duration, and intended use. In protected areas or co-ownership, additional constraints may apply. It is therefore recommended to inquire at the town hall and, if necessary, with a design office.

Routine and preventive maintenance

Routine maintenance of a used container includes cleaning the floor and walls, checking seals, lubricating locking mechanisms, and inspecting rust spots. It is advisable to quickly treat any scratch or paint chip to prevent corrosion from spreading. Door seals can be replaced when they harden or crack. A well-maintained container can serve for many years, whether for storage or more specific use.

Preventively, a quarterly visual check helps identify changes: paint blistering, superficial rust marks, deformation of a locking bar, hardening of seals. Cleaning is done with clear water, using a soft brush for the floor and a sponge for the walls. Aggressive detergents, chlorinated solvents, and pressure washers directed at the seals should be avoided, as they can degrade the rubber and force water into gaps. After cleaning, air-drying with doors open limits mold growth on the plywood.

For areas of incipient rust, light sanding followed by an anti-rust paint suitable for Corten steel is usually sufficient. If corrosion has perforated the metal sheet, repair by welding or by applying a riveted, watertight patch is necessary; this work should be done by a professional to preserve geometry and tightness. Door seals are easy to replace: they are usually fixed with a fitted or glued profile, and their cost remains moderate. Locking mechanisms should be lubricated with a light grease, without excess, to avoid attracting dust. Finally, it is prudent to slightly raise the container and clear vegetation around it to limit stagnant moisture and rodent access.

Practical buying tips

Ask for recent photos and, if possible, an on-site visit. Check the marking, serial number, and CSC plate. Have the Wind & Watertight guarantee specified in writing, along with its duration and scope. Inquire about the container's origin: a container that has carried chemicals or foodstuffs may require specific cleaning. For food or sensitive use, a cleaning certificate can be requested.

Plan the delivery and unloading method: a truck with a crane is often necessary, as an empty container weighs over two tons. Anticipate the location, access, and ground stability. If you plan a conversion, check technical feasibility (drilling, insulation, electricity) and permits. Finally, compare offers taking into account the actual condition, transport costs, and guarantees, rather than just the advertised price. A well-chosen and well-maintained used container remains a durable investment for many uses.

In summary

The used 20-foot Dry container is a versatile and economical solution, suitable for many needs. Its ISO standardization ensures compatibility with global transport infrastructure, while its Corten steel structure and marine plywood floor offer proven resistance. Refurbished and watertight, it is a reliable base for storage, construction sites, or export. As with any used equipment, the actual condition of the container and warranty terms must be verified with the seller. An informed purchase, with careful inspection and regular maintenance, allows you to get the most out of this container over the long term.