How to build a shipping container home
Before we dig in on how to build a shipping container home, you should make sure that you have done the appropriate research on the benefits and drawbacks of a container home. Determine that you are making the best choice for your particular situation.
So ahead of explaining how to build a shipping container home, we will briefly run through a couple of important considerations when it comes to shipping container homes.
Things you should know about shipping container homes:
A strong structure
The container has been designed for shipping and stacking and works best in it’s original form and function. As soon as you start to modify the structure of the container, like cutting openings for windows etc, you start to compromise the containers strength and you will have to reinforce with steel beams to ensure it again. Also a container is designed to be stacked in a certain way. If you stack it differently you are yet again compromising the its strength and you will need to reinforce it. Check under the section Stacking containers on the Wikipedia entry of Intermodal Container.
Much in the same way that the strength of a box of corrugated cardboard looses its strength when you cut holes in it, the container looses its strength too. You may not see it right away, but over time it will deteriorate.
A container is just a basic rather small box that you will have to condition with insulation, electrics and add everything else like windows, doors, kitchen, bathroom etc.
There are several sizes of shipping containers, but a container on 40 ft is made of 8380 pounds (3801kg) steel which could actually be made into about a 1000 8 ft (2,4m) long steel studs. So if you were using about 150 of these studs to build steel framed houses of the size of a container that give you around 6 container sized houses.
Steel is a very heat (and cold) conductive material, which means that the heat and the cold travels very well through it. As a result, in hot climates it will become very hot inside and in cold climates it will become very cold. Being the container a complete steel structure you have to make sure that you insulate very well. Spray foam is the recommended way to go here. You have to make sure that there are no “holes” in the insulation, as that would act as a thermal bridge and your insulation will loose its effect. This could also lead to a problem with condensation and hence growth of mold or corrosion.
Container homes are not ecologic
You may have heard it said that re-purposing a shipping container and make a home of it, is an ecologically sound solution. This is debatable however and here is why:
There may be a surplus of containers in the world, but in spite of this, most of the living spaces made of containers, will more often buy new containers from China or fairly new containers, like one-trip containers. This is so because that is the best way to get a container in good condition and one that haven't been used to ship something toxic. If it has been used to transport something toxic or you are unable to verify that it has not, then you would have to clean it very thoroughly or better still, get it sandblasted.
Reason for building a container home
When all this has been considered you may still want to build a container house. Reasons for having to build with containers could be that you need something that does not have a “permanent look to it” due to regulations in your area for instance. Or perhaps it is difficult to get materials to the site where you want to put your house. In this case you could even partly finish the module before you put it at your site. You may be looking for the security of a locked container may offer you (in this case mind how you modify it). Another thing to point out while we speak of security is that a shipping container is not something you would want to bury and use as an underground bunker or as a swimming pool. It would need some serious reinforcement for that use or it will just collapse in a couple of years.
So, how to build a shipping container home?
You should proceed in more ore less this order:
Start designing your container home. You can start with just a pen and paper, Auto CAD or any other design tool. Google's Sketch-up is a pretty good and free option for designing and you can even download 3D container models from the Sketch-up Warehouse with the correct sizes and there are even finished models that may help you understand how to build a shipping container home. You will also find models from the warehouse to furniture your container home.
Be prepared for tossing your designs several times before finding the one that suites you. Do not despair. This is just a part of the process.
Take into account tubing for kitchen and bathroom, electrical wiring, heating and cooling while doing the design.
Keep in mind while doing the design that the corrugated sides on the container gives strength to it and also holds the roof in place. So try not to cut out too much. If you need to cut out much, then remember to reinforce and also try to maintain at least 3-4 feet of side wall towards the corners. This is particularly important if you plan to stack containers on top of each other.
If you place two or more containers adjacent to each other then it is a good idea to weld them together at the corners. This gives the structure back some of its strength.
2. Choose foundation
The pier foundation: A shipping container is designed for weight bearing on its 4 corners, so one pier in every corner is really the best way to go. However, as your design probably incorporates cuts for doors or windows, you may want to put additional support to these areas.
If your piers are made of concrete or similar you could bolt the container to it or you could embed a pad of steel on top of you pier and then weld the container to these.
A pier with footing is ideal. Dig your pier to extend below the frost line, so that they won't move with the seasonal changes.
You can make your own form or get a Sonotube form.
The slab foundation: This is another option but depending on the weather conditions in your area you may want to make sure that the steel is above ground so that it will not be standing in water for longer periods of time.
This calculator for estimating the amount of concrete necessary might be useful to you.
3. Choose roofing
You will need some inclination on the roof to avoid rain and snow accumulating on it. We suggest you leave some space between the roof framing and the container roof for insulation and potential duct-work etc
In most of the cases it is recommendable to remove the factory flooring as it may be treated with insecticides or other chemicals. Use a mask as the manipulation will create dust infused with insecticides and it is not recommendable to breath that into your lungs.
Once you have placed your containers (if there is more of them) in the desired position and you have done the planned cuts for windows, doors and tubing etc, the time has come to take care of the insulation. First make sure that you seal the gaps that will be created between containers with spray foam and then apply spray foam insulation to insulate the walls and floor of the container. You may skip the spray foam insulation on the interior of the ceiling if you are planning to insulate the roof. Do not be cheap with the foam insulation as this can cause great heat-/cooling loss and give you problems with humidity due to condensation. It will be much more expensive to try to find ways to compensate for lack of insulation later.
6. Wires and tubing
At this point the electric wires is usually laid out and tubing for kitchen and bathroom prepared.
7. Install floor and drywall
The above steps are only meant as an orientation. We urge you to inform yourself well and if your design is complex consult an engineer to get the strength of your design confirmed.
There are several good books on Amazon.com to help you through the design and building process.
You may also want to check the delivery time of your container before you start ordering material or labor help as it some times may take quite some time before the ordered container is delivered to you. It may actually take as long as 2 months.
As a final suggestion: Container houses is the new popular thing right now, but we would like to suggest that you consider going for tiny house instead of a container house. It will probably turn out to be cheaper per sq foot and it is easier to accommodate with correct insulation and the utilities a house should have.