First and foremost, before we discuss the construction of the foundation, the most important tip you need to consider about your shipping container home foundation is the type of foundation you need.
Oh sure, this sounds easy, but there are three very different distinct styles of foundations and there are several questions to answer before you begin converting the shipping container into a home.
FAQs Before Shipping Container Home Foundation Creation
How permanent is this structure in this location?
Do you plan to stay on this plot of land for years to come or are you considering moving the container in the near future?
One of the attractive designs in shipping container homes is that they can easily be moved and if you plan to relocate in a short time, there is little reason to shell out big money for an elaborate shipping container home foundation build. However if you do plan to stay put, a more stable foundation may be desirable.
What kind of soil are you planting your shipping container home on?
The foundation of any home is where all the strength and stability comes from. The metaphor has been over-extended in countless stories and books, but it remains true; don’t build your house on sand, build it on rock.
And if you find yourself in poor or weakly packed soil you may not have a choice in the type of shipping container home foundation you create, you may need a robust foundation to keep you in place.
How much weight are you planning to support?
A simple shipping container home foundation can support an amazing amount of weight with minimal contact points because of how the shipping container is designed and constructed.
But since we are altering them, cutting them, possibly adding a second story, and generally ignoring the weight distribution load recommendations in order to turn them into a home, you must consider the final weight of your construction and plan a proper shipping container home foundation for the intended final result.
What kind of weather does your land receive?
If you find yourself receiving flash floods, or large accumulations of rain or snow, you may want an elevated shipping container home foundation in order to keep you out of the elements. If you are in a wind prone area that could receive hurricanes or tornadoes, you may need to build low and heavily anchored to the ground.
If you are in an active seismic region, you should plan for lateral shifting as well as a reinforced shipping container home foundation. Know your land before beginning.
What is the budget for the build?
Do not scrimp on the shipping container home foundation. As stated, it is more important that you think. If you know you need a robust foundation but don’t have the budget for it yet, consider delaying the build until you can get the proper shipping container home foundation you need. Starting off wrong will only exacerbate problems down the road.
The Three Main Shipping Container Home Foundation Types
Once you have answered these questions, you can then carefully consider the three basic styles of shipping container home foundation builds.
Driven Piles
These are necessary for loose or unreliable soil. This is the same construction they use to build bridges, skyscrapers or other structures that require the utmost stability. Long posts are driven into the ground, through the loose soil until they finally reach the bedrock far below.
These steel or concrete piles are then used to support the container. Due to the permanency, and the high cost of driving these piles into the ground, unless absolutely necessary, this is not the most common shipping container home foundation.
Standing Piers
The ideal shipping container home foundation for ease of setting up, low cost, future access to utilities, and for the container that you plan to move in the future. Because of their construction, shipping containers do not need many support points.
Six piers is sufficient for most containers, one in each corner, and then two at the mid-points on each length to prevent any sagging due to container alterations. The equivalent of putting your home “up on blocks”, pier foundations is ideal for solid soil locations where you can relatively rely on the stability of the ground.
Slab or Trench
Driving piles may turn out to be necessary but expensive. Standing piers may be convenient but insufficient for long-term housing. By far, the most reliable shipping container home foundation for the builder that plans to remain in the same location is the slab on grade, or strip trench foundation.
This foundation requires excavation, pouring of concrete, and anchoring of the shipping container, but once complete, provides a solid and reliable foundation. The outline of the shipping container is dug down generally about one foot wide and two feet deep, local regulations or soil may call for alterations but in general, this outline is filled in with concrete.
If you only fill the outline and rest the shipping container on these beams, you have a trench or strip foundation. Most builders opt to pour the space in between the beams, about four inches deep creating one monolithic slab. This slab can be covered with a plastic and sand barrier to prevent heat loss and moisture intrusion.
What Is Involved With Foundation Construction?
The construction of a slab-style shipping container home foundation is an involved process that is labor-intensive for the DIY type, but not impossible. It is by far the most common shipping container home foundation chosen as it offers stability on any soil type. The deeper footer beams and shallow slab act as an anchor that resists shifting soil.
Even rocky and solid ground shifts and settles a bit over time, on a slab your shipping container home tends to move all at once rather than on the individual piers or piles. This “Frisbee” style foundation holds the ground below your shipping container home together under ordinary circumstances.
Our Final Thoughts
Once you answer these initial questions about the type of structural base that is best for your kind of location and installation, you can begin construction on your shipping container home foundation. Bear in mind these tips we have laid out as a guideline to ensure you consider the variables in your case, the pros and cons of each style.
Cheaper isn’t always better, and careful planning is always best.