How to Build a Double-Wide Shipping Container With a Weldless Header Kit
Follow along as Channing walks through the process of joining two 40-foot high-cube shipping containers to create a 16-foot-wide, 40-foot-long structure using Container Modification World’s Double-Wide Header Kit.
Creating a double-wide shipping container is not as simple as cutting out the sidewalls and pushing two containers together. Removing the walls affects the strength of both the roof and floor, so the structure needs to be properly reinforced before the containers are joined.
Choosing the Right Shipping Containers
Container selection is extremely important for a project like this.
For this build, one-trip 40-foot high-cube shipping containers were used. Containers without fork pockets are preferred because fork pockets interrupt the floor structure and can make reinforcing the container more difficult.
Before removing the sidewalls, 5-inch-by-3-inch angle iron was installed inside the lower C-channel to strengthen the floor. Flat bar was later installed between the two containers to create a smooth transition between the floors.
Installing the Double-Wide Header Kit
Container Modification World’s Double-Wide Header Kit was redesigned so the complete system can now ship on a 4-foot pallet.
The kit uses structural corrugations, Z profiles, J profiles, ridge cap sections, and structural rivets to create a continuous header across the full 40-foot span.
The Z profile fastens directly into the shipping container’s upper 60 mm tubing using 5/16-inch flange-head thread-cutting bolts. The J profile wraps around the structural corrugations, while overlapping seams help prevent differential sagging along the header.
Sealant is also applied between the layers to help keep water and melting snow out of the center cavity.
Connecting the Shipping Containers
High-Capacity Bridge Fittings are used at the corner castings to pull the two containers together and keep them aligned.
These fittings provide a strong mechanical connection and are especially useful when the containers are not perfectly positioned. A come-along can also be used to help bring the lower sections together before the fittings are tightened.
Once the containers are aligned, the ridge cap can be installed and riveted into place.
Finishing the Interior
The Double-Wide Kit also includes End Caps that cover the exposed corner posts where the containers meet.
The interior was framed using 1 5/8-inch steel studs, leaving enough space for closed-cell spray foam insulation around the structure.
Container Modification World Wall Flashing Kits and Door Flashing Kits were also used around the original shipping container doors. These products help maintain active container doors while creating clean surfaces for insulation and interior finishing.
For additional framing, a strut-channel system was installed along the base, upper walls and ceiling.
Steel Stud Brackets and Insulation
For a more residential shipping container interior, Container Modification World Steel Stud Brackets can be used with steel framing.
The Composite Steel Stud Bracket reduces thermal bridging and is especially useful in colder climates, while the Aluminum Steel Stud Bracket provides a more rugged option for warmer regions.
Closed-cell spray foam is recommended because it provides insulation, an air barrier and a vapour barrier while also helping stiffen the container structure.
A DIY Double-Wide Shipping Container Solution
With the Double-Wide Header Kit, High-Capacity Bridge Fittings, Door Flashing Kits, Wall Flashing Kits, End Caps and Steel Stud Brackets, much of the complicated fabrication involved in joining shipping containers can be simplified.
The finished result is a large 16-foot by 40-foot interior that can be transformed into a container home, garage, workshop, office or other modular building.