All over the world people and organisations are building small houses, community facilities, libraries and even promotional kiosks from shipping containers. Whereas setups like promotional kiosks are mobile, when you’re creating permanent structures from shipping containers a good foundation is critical.
Whether you are building a workshop, an office or a house, the foundation carries the entire load of your structure. Without a well-laid foundation you may end up with uneven floors or worse, the entire structure could sink. If you are stacking containers on top of each other they may even topple if you have a faulty foundation.
The faults in the foundation may become apparent immediately or they may begin to affect over a period of time. The Leaning Tower of Pisa is a good example of an ill-planned foundation for a heavy structure. The tower was constructed on a soft ground of mostly clay, fine sand and shells, without paying much heed to the importance of laying a good foundation. As the construction proceeded and the weight of the tower increased, it started leaning by the time the 2nd floor was up .
What sort of foundation you are going to lay for your shipping container building project?
To answer this question you need to be aware of the various factors that can impact on your foundation. These include:
- Total weight of your container construction
- The nature of the soil on the site
- Water level
- Sanitation and drainage requirements
- Material and labour costs
- Local building bylaws
- Climate of the region.
Once you have this information then there are 4 main types of foundations you can have for your container building project:
1. Concrete slab foundation
2. Concrete footings
3. Wooden beam footings
4. Multi-directional steel pipe footings
Let’s check out these shipping container foundations in more detail…
1. Concrete slab foundation
This is the most expensive and time consuming way of laying a foundation for your container building project and it is mostly used for larger installations. The expense involves the cost of the concrete and the labour that you may have to hire.
Laying a concrete slab foundation involves, as the name suggests, creating a thick concrete slab upon which you eventually place your container. The thickness of your concrete slab foundation depends on the nature of the soil underneath it. For example, if the soil is firm you can simply remove the grass, create a wooden structure of the same size as your shipping container and then pour concrete into it.
Pouring concrete into a wooden frame isn’t as simple as it may seem and you may require extra help. The liquid concrete needs to be poured into the wooden structure with speed before it begins to congeal and solidify.
Even if the soil is firm, environmental factors such as frost and evaporation means the ground beneath your slab will be constantly changing shape. So you may have to dig and create extra concrete padding at strategic locations.
2. Concrete footing foundation
Unlike concrete slab foundation, concrete footing doesn’t cover the entire area. It helps distribute the load of the construction over a larger area, especially in sync with the walls of the container and the places where you expect the weight to be the greatest.
In order to lay a concrete footing foundation you dig a trench in the shape of the container (or in the shape of the area you’re going to cover with multiple containers) and then quickly pour liquid concrete into it. The footing has to be of sufficient thickness and the concrete mix should be flexible to some extent . The flexibility will ensure no cracks appear later on.
Since you are not covering the entire area with concrete, the concrete footing foundation is cheaper compared to concrete slab foundation.
3. Wooden beam footing
Wooden beam footing is suitable for almost all soil types and it is much more economical compared to concrete footing and creating concrete slabs. These wooden beam footings can be easily installed just before your container is delivered. The materials that you need can be easily obtained, such as treated 4” x 4” wood beams (or railroad sleepers) and loose stone or gravel.
You can install the beams at the four corners of the construction site to place the four corners of the container (assuming you are using a single container for construction) onto them. In most of the cases, the frame of the container ensures that no extra support is needed underneath but if you feel there are pressure points that may make the floor uneven you can install more beam footings under those points. The gravel bed will drain away extra moisture and keep your beams from rotting.
Wooden beam footings are also used in high flood areas where the property needs to be constructed on a raised platform, giving the flood water enough space to flow underneath the construction.
4. Multi-direction steel pipe footing foundation
Surefoot is an innovative way of laying a sustainable foundation with least amount of effort. Pioneered and marketed by Surefoot Footings, this technique involves a cost-effective way of creating a solid support structure under your container construction without excavation or concrete. It uses the laws of physics to nullify and absorb heavy load and stress. Aptly nicknamed the “metal tree stump” it works according to the root system of a tree.
The central Surefoot device is used to create and sustain the system. Galvanised steel pipes are passed through the holes in the device and then drilled into the ground using a jackhammer. The holes in the Surefoot device make sure that the pipes are dug into the ground in different directions, diagonally away from each other.
Once it is installed and the container construction is placed over it, it spreads the weight over a greater surface area enabling the foundation to absorb more weight with greater efficiency and durability. Just like the roots of a tree, the pipes hold on to the ground tightly besides distributing the massive weight of the container.
The accessories needed to install Surefoot foundation blocks can be easily obtained and it takes just between 10 to 30 minutes to fix a basic Surefoot stump, depending on the size of your container construction.
Shipping containers of all standard sizes for your next construction project
Are you looking to construct a house, a storage area, a shop, or anything that requires a strong, modular container? We provide new and used 10 feet, 20 feet and 40 feet shipping containers at highly competitive rates. Contact our team of container experts with your requirements – we offer a nationwide delivery service and can transport the right-sized shipping containers to your site by truck, rail or sea, using the best cost effective and efficient combination that works for you.
