How to Stack Shipping Containers Safely in the UK

Shipping containers are designed to be stacked securely, making them one of the most versatile storage and building solutions available today. From maximising storage space on industrial sites to creating multi-level container conversions, stacking containers opens up huge possibilities.

However, stacking containers is not as simple as placing one box on top of another. If you want to achieve a safe, long-lasting, and compliant container stack, there are several important factors you must consider first.

At S Jones Containers, we’ve been supplying, converting, and stacking containers for over 40 years. In this guide, we explain everything you need to know about stacking shipping containers in the UK, including safety checks, methods, and how to secure your containers for the long term.

Why Stack Shipping Containers?

Businesses across the UK choose to stack shipping containers for a variety of reasons:

Maximise floor space – Ideal for sites where ground space is limited.
Scalable storage – Add capacity quickly without buying or renting more land.
Durability – Shipping containers are engineered to carry heavy loads.
Conversion opportunities – Multi-level office blocks, workshops, welfare units, and plant rooms can be built using stacked containers.

Whether you need to store stock, expand facilities, or create a bespoke modular building, container stacking is often the most practical solution.

Step 1: Check the Condition of Your Containers

Before stacking, always make sure your containers are structurally sound:

Inspect for damage – Look for dents, bowing, holes, or corrosion.
Check roofs and flooring – These are pressure points that must withstand weight.
Review container conversions – If the unit has been modified (with windows, doors, electrics, or partitions), ensure reinforcements have been added to maintain load-bearing strength.

Failing to check container condition before stacking can lead to instability and unsafe working conditions.

Step 2: Prepare the Ground

The foundation is just as important as the containers themselves. In the UK, the safest base for container stacking is a flat, hardstanding surface, such as concrete.

Flat surface – Prevents containers leaning or shifting.
Drainage – Stops water ingress, which can cause rust.
Hardstanding or concrete slab – Provides a stable foundation that can support weight.
Anchor points – Twist locks or base locks can be installed to secure the containers against wind and movement.

Without proper ground preparation, even the strongest containers can become unstable when stacked.

Step 3: How to Stack Shipping Containers

There are two main methods for stacking shipping containers on land:

Using a Crane

Containers are lifted using corner castings for even weight distribution.
A crane provides precise placement and is the safest method for stacking multiple levels.
Suitable for both storage yards and conversion projects where accuracy is essential.

Using a Forklift

Forks must be at least 96 inches long with a lifting capacity of 15,000 lbs or more.
Best for stacking one or two levels only.
Always use a trained and experienced operator.

For larger stacks or container conversions, cranes are strongly recommended for accuracy and safety.

Step 4: Securing Container Stacks

Even though ISO containers are designed to interlock, you should never rely solely on weight to hold them in place. Proper security is essential:

Twist locks – Installed at the container corners to lock units together.
Base locks – Secure the first layer to the ground.
Cross bracing or reinforcements – Especially important for converted units, where windows or doors reduce structural strength.

By securing your stacks, you reduce the risk of movement caused by strong winds, uneven ground, or heavy usage.

How Many Containers Can You Stack?

The answer depends on your application:

At sea – Up to nine containers high (on ships with specialist securing systems).
On land – Usually two to four containers high, depending on ground stability, local wind conditions, and structural reinforcements.
Converted containers – Office blocks, welfare facilities, and workshops require a professional assessment. Modifications affect load-bearing ability, and building regulations must be followed.

At S Jones Containers, we provide expert advice on safe stacking heights for your specific project.

Local Expertise Across the UK

We’ve worked with clients throughout the UK – from Birmingham and the West Midlands to London, Manchester, and Leeds – helping businesses with container stacking, storage, and conversion projects.

Whether you’re expanding a storage yard or building a multi-level container office, our experienced team will ensure your containers are stacked safely, securely, and in compliance with UK standards.

Why Choose S Jones Containers?

Over 40 years’ experience in container supply and conversions.
Nationwide coverage with fast delivery across the UK.
Dedicated conversions team to advise on stacking modified containers.
Full support from supply and stacking to design, engineering, and installation.

Get Expert Help with Container Stacking

Stacking shipping containers can unlock valuable space and new opportunities – but only if it’s done safely. Whether you’re planning a multi-level storage system or a container conversion project, our team can guide you through the process from start to finish.

Contact S Jones Containers today to speak with our specialists about container stacking, supply, and conversions.