One of the great things about shipping containers is that they can be stacked on top of each other, maximising floor space and storage. If you are planning on stacking shipping containers, however, there are several things you need to consider beforehand to ensure that you do so safely.
We’ve pulled together an overview of what you need to do to properly stack shipping containers below. These principles do vary slightly depending on the use you have for your shipping containers – transport, storage or conversion – but this should still allow you to get off to a strong start with your container stacking.
Check the Condition of Your Containers
Before you get started with stacking your shipping containers you need to make sure they are all in good condition. If your containers are not solid and structurally sound they may struggle to hold the weight of anything stacked on top of them, creating dangerous conditions. Inspect your containers and ensure that they are not bowing and all panels are without holes or considerable dents. It is also advisable to check both the flooring and roof of your containers to ensure there are no signs of weakness here.
If you are stacking converted containers, you will also need to ensure that any modifications made have not impacted the structural integrity of the unit and that any weight added to the containers has been properly reinforced.
Prepare the Ground
Once you are sure your containers are in good order, you similarly need to make sure the place where you intend to stack your units is appropriate. Containers should be stacked on a flat surface. This is so that you have a stable base for your units that prevents any water ingress underneath them, which could cause issues with rust.
Concrete slabbing or a similar type of hardstanding is the best type of base for stacking containers not being used for transport. Hardstanding provides a solid footing that will prevent movement and subsistence beneath the weight of your shipping container stack.
It is also worth installing anchor points to your base to ensure that containers do not move in the stacking process or as a result of wind. Twist locks are a great option to secure your containers to their base.
How to Stack Containers
Once your containers and base are ready it is time to start stacking!
The easiest way to stack containers is by using a crane. This will allow you to quickly and easily manoeuvre your units into position. To use a crane for this job all four corners of your container will need to be attached to the crane using corner castings to equally distribute the weight. The crane operator can then precisely stack the containers on top of one another.
You could also use an industrial forklift to complete stacking. If you do go down this route, you will need to consider how high you want to stack your containers and ensure that the forklift you plan to use has at least 96-inch forks and a weight capacity of at least 15,000 lbs. Your forklift driver will also need to be experienced to ensure that your containers are stacked safely.
Securing Container Stacks
Although ISO container standards mean that shipping containers should stack well on top of each other, you still need to secure them to each other to prevent movements and falls. The most common way to secure container stacks is by using twist locks. These are fixed at each corner of a container and secure it to the one above.
As discussed above you can also place twist locks in the concrete base of your stacking site to ensure that all your containers are secure, helping to prevent them from movement by strong winds.
How Many Shipping Containers Can You Stack?
It is possible to stack up to nine containers for transport at sea.
It is worth noting, however, that conditions will not always allow the same height on land. When using shipping containers for on-land storage, consider ground conditions, access and wind before stacking containers high, particularly long term. The height of a nine container stack can be a hazard in windy conditions.
When stacking converted containers for offices or other uses, you are best talking to a specialist team as modifications and electric and access requirements will impact the number of containers that can be safely stacked. Our conversions team at S Jones will be able to help with any queries you have on this.
This guide should give you some insights on how to stack your containers safely and efficiently, giving you a cost-effective way to store large quantities of goods. If you need any assistance expanding and stacking your shipping container stock or conversions, please get in touch with the S Jones team!
