Merging two containers.
Merging two containers to create a larger shipping container home.
Placing two shipping containers side by side is a very common thing to do when building with boxes 8ft wide. When building a home involving two units side by side you must remember two things.
One, you must seal the two units properly to prevent any water leaks, and two, the foundation must be perfectly level. During the installation, after the first unit is in place you will need several people helping, with ropes, guiding the second swinging container into its proper place. Double check, measure and be 100% sure that they line up. Once we have the two units side by side we use several industrial vices to squeeze the units together. The protruding corner posts on all shipping containers prevents a perfect seal when two units are side by side.
The method we use to create a seal is with roofing cement, thin sheets of metal and welded corner posts. Once the two containers have been set side by side on their foundation then you can begin to weld the units into the foundation and the adjoining corner posts. Before applying the roofing cement you must first install the rolled roof flashing inside and outside the opening. The combination of these three should create a perfect seal.
The above photos show the type of materials that we use. Backer Rod is sold in most hardware stores and is very inexpensive. It can be found in the plumbing section and is sold in different thicknesses.
As seen in the photos we stuff this in the gap of the container and then squeeze in Duritan. This is a sealant sold in Costa Rica. In the states you will want to ask your local store which material is the best to seal these boxes. They will have exactly what you need and all you will have to do is apply the substance on top of the backer rod.
When stacking shipping containers on top of each other, the weight load needs to go through the corner posts and therefore through the foundation. Also if you plan on removing some of the side panels your structure will lose some of its integrity. The side rails do not have much strength when your remove the corrugation.
The steel beams you weld into place will need to be at least 4×4. (as seen in the photo below with the two black steel beams in the center of the container home) This home actually has a third shipping container on top and a roof top deck.
It is always recommended to stack the containers so the corners match up. This is what their original design was created for. When you start staggering containers and placing 20ft units on top of 40ft units and then cutting out walls, you run into some structural issues. Firstly, there are no current structural engineering reports on any irregular stacking of shipping containers. The only real structural information available is from the shipping container manufactures.