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How to Stack Shipping Containers

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When construction space is limited, you don’t have the room to store as many materials and equipment as you need. If your space is tight, renting stacked shipping containers gives you twice the storage room while saving ground space. Space limitations may also force you to forgo having a mobile office on your job site.

Going off site for meetings and materials makes it more challenging to keep your construction project on task. It can also cost your company time and money. With stacked shipping containers, you can have an office on the ground and store important items in the top container. There are lots of possibilities. In this blog, we’ll look at how to stack shipping containers and why stacking reduces cost and stress.

Stacked shipping containers at Southwest Mobile Storage's container yard.
Stacked shipping containers can save room at a construction site with limited space.

Stacked Shipping Containers Maximize Space

Renting storage containers makes it easier to access equipment and materials, so you don’t have to pay someone to retrieve them daily. As a result, your construction company saves time and money and becomes more productive. Meanwhile, mobile office containers provide a safe, comfortable office environment onsite for superintendents to oversee the construction site. This allows you to respond quickly to any problems while ensuring the project is kept on track to keep your clients happy and maximize your profits.

Renting a container or mobile office for your construction site has many incredible benefits. But, with limited spacing, you may have to choose between the two. You can have a storage container and a mobile office onsite or double up on storage containers to get twice as much storage using the space reserved for only one container.

For example, stacking two 20-foot shipping containers at your construction site allows you to keep your most used equipment, such as heavy tools, in the bottom container and then store any other tools in the top container — especially those that aren’t used as frequently or won’t be needed until much later.

When you stack your containers, you only use the space one container would take up while still enjoying the cubic storage feet of both containers. This lets you have the site control of a mobile office and the convenience of a storage container even when your construction site has limited space. So, your construction company gets to save time and money while improving profit and reputation.

How to Safely Stack Shipping Containers

Stacking containers requires careful attention to safety to reduce the risk of injury and death for the public and your crew and ensure your stored materials are not damaged. Occupational Safety and Health Administration (OSHA) has set guidelines for safely stacking cargo containers. Your construction company is always responsible for ensuring you comply with OSHA guidelines when renting storage containers. This is especially true for the top container, which you should use for tools you won’t frequently use. If you need to regularly access the top container, check any requirements or conditions set by OSHA regarding ways to access the top container, such as stairways.

Here are four tips to help you get started with stacking shipping containers:

1. Stack Shipping Containers on Level Ground

If your containers are unstable, they could fall and seriously injure or kill anyone underneath. Level ground increases the stability of your shipping containers, reducing the risk of falls. So, it’s always important to place containers on level ground. Place the first container in an area that will allow easy access and is sturdy enough to bear both containers’ weight and any equipment you will store inside. You can check out our shipping container dimensions and weight guide for more information.

Construction workers laying down concrete to create a foundation.
Stacked storage containers allow you to securely keep important construction items at the job site instead of at a remote location.

2. How to Move Stacked Shipping Containers

Using the wrong machinery to lift your containers risks accidents that could damage your equipment or injure people nearby. Cranes and forklifts can handle the weight of empty containers and safely lift them, helping you protect people at the job site and the machinery. Only use forklifts and cranes that can handle and lift the weight of an empty container. An empty 20-foot container weighs about 5,000 pounds, and an empty 40-foot container weighs around 8,500 pounds.

20-foot shipping containers come with forklift pockets. These pockets are spaced 69 inches from each other, so you must ensure that your forklift can fit this length. If the forks don’t reach that length, they should be at least 8 feet long to lift the container from the bottom. This is especially true for 40-foot containers, which do not have forklift pockets.

3. Only Stack Same-Size Shipping Containers

Stacking containers that are not the same size can lead to uneven weight distribution. This increases the risk of damaging the structural integrity of the bottom container. To prevent the bottom container from collapsing and ensure the safety of your crew, make sure you only stack storage containers of the same size. In addition to only stacking containers of the same size, ensure the weight of the top container does not exceed the weight of the bottom container once loaded.

4. Always Lock Stacked Shipping Containers

Use container locks whenever you can to prevent the stacked shipping storage containers on your construction site from shifting. Every 20- and 40-foot shipping container comes with four corner posts or castings that allow containers to be locked into place. This is how they are locked together while on cargo ships.

When locking containers together, the most common mechanism you can use to secure your containers is a twist lock. Twist locks are a staple in the shipping container industry and allow you to twist the lock, usually with a lever or knob, to lock the containers in place. They are lightweight, made with all-steel construction and can be purchased from transportation and shipping industry parts suppliers.


Renting stacked shipping containers for your construction site is a great way to use a limited space while gaining considerable cubic feet of storage. When space is tight, you don’t have enough room to store the materials and equipment you need. If you’re limited on room, renting stackable shipping containers can double your storage without sacrificing additional ground space. Southwest Mobile Storage provides the highest quality, safest containers along with the best value, service and expertise – and pricing you can rely on.

Request a quote now to see how Southwest Mobile Storage can assist with your next construction project.

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Looking to learn more about the benefits of shipping containers at a construction site? Visit our shipping container FAQ page or check out these informative blog posts:

Or watch this short video on customizing a 20-foot storage container with insulation, electricity, HVAC and more.

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