The interior framing is mostly done, except for a couple of the partition walls. As mentioned previously, I chose to use 1 5/8″ UltraSTEEL steel studs from Dietrich Metal Framing for the space saving aspect over traditional wood studs. In retrospect, I’m not so sure I would do it again. I only saved about 2″ on two sides of the cabin, which worked out to be just six square feet of floor space. While building the steel walls is not that difficult, it is time consuming when you have to clamp and screw each stud in four places. Building a traditional wood framed wall is so much easier, especially when you have a power framing nailer.
Before I set the stud walls in place, I affixed 1/2″ foam sheathing on the upper box beam to create a thermal break between the steel studs and the shipping container. Since steel conducts heat so well, a direct connection between the studs and the container would cause heat loss through the walls. The cold studs could also cause formation of condensation on the finished drywall. This additional step would probably not have been necessary with wood studs, and is yet another reason to just stick with wood studs.
The upper track is secured into the box beam with #10 thread cutting screws from Fastenal. I pre-drilled the screw holes using a 5/32″ drill bit – the steel is fairly hard so plan to use a cobalt bit if you do this. I also left a 1/2″ space above the upper track to add some spray foam insulation between the studs and container. If you’re wondering what the group of nine holes are in the picture, they are part of two ventilation ports that were in each container. There are only two left since combining the containers, and I do plan to keep them functional for added ventilation. They are already screened and protected from the weather on the outside, and I plan on attaching PVC pipe to them on the inside to pass through the drywall.
The bottom track is just simply attached to the wooden floors using 1 1/4″ coated decking screws. Coated screws should be used to resist any treatment chemicals that might be present in the plywood floors.
Thanks for posting the details of building this project.
I am filing all your descriptions and plan to use them as a guide when I build.
Did you have the containers set into the exact position they would be or can they
be moved around at all once dropped by the delivery service?
Jim:
Take a look at my article The Containers Arrive that shows the containers being set into place. The containers were set close to their final position by the crane, and then the final adjustments were made with a long crowbar. I was surprised by how little effort it took one person to move a shipping container with just a crowbar. Keep in mind that my foundation had steel plates embedded in the concrete, and I’m sure that helped the containers move around on the foundation.
The containers were also “squeezed” together with come-alongs when it was time to weld them together. I’m sure you could use these to move containers around as well.
Keep me up to date on your project and let me know if I can be of any help.
Steve
Thanks for your post and hope everything is going well.
I am planning to build home by 4 shipping container, I have a little question. If I plan to cover everywhere interior with drywall, and using light gage steel stud, I was wondering if the screws might penetrate steel exterior wall. Do you know if there is any good idea?
David:
A typical drywall screw isn’t long enough, or even strong enough, to penetrate the steel exterior walls. Even with the 1 1/2″ steel studs I used there was still about a 2 1/2″ distance from the interior drywall surface to the closest container wall corrugation. I think I used 1 5/8″ coarse thread drywall screws.
Steve
Thanks for your reply, Steve.
But what I meant was that I am worried that the screw might penetrate container wall corrugation when I install the light gage steel frame to container. Probably I might need to weld huh?
David:
The third paragraph and third picture above explain exactly how I secured the upper steel stud track to the container. The track is screwed into the upper box beam and not the container wall. As such, it passes through the inner side of the box beam but not the outer. The stud walls are only attached at the top and bottom through the tracks and not the studs. There’s really no need to go through the trouble of welding. Hope this answers your question.
Steve
Hi Guys
I wanted to comment on this framing dilemma because I have been researching building with shipping containers for over a year now and have done 2 already, hopefully a lot more to come, but for metal studs there is an amazing tool you can buy that spots welds the studs right to the wall.
The sprayfoam if applied right will cover all the metal and make the proper thermal break. If you weld the walls together and then weld them on the container the sprayfoam can in between the gaps and stop the cold spots.
Steve, Did you use a sprayfoam installer or did you get your own kits?
Good job hopefully we can talk more
Cheers
Tim
Hi Tim:
I would love to see some pictures of this to see how it works, but I still think I would use wood next time. The speed of framing a wood wall with the additional strength for hanging things is tough to beat.
In regards to the spray insulation, I hired it out. I looked into some of the DIY kits and the price wasn’t that different.
Regards.
Steve
Hi Steve, with a wood framed wall, would you still go with the sprayfoam insulation or would you consider regular insulation…or would you be concerned with condensation forming on the steel wall behind your insulation and wood framed wall? Thanks!
Fred:
I would never use anything other than closed cell spray foam insulation for the interior of a container. While you could use something else and a vapor barrier, the vapor barrier would need to be absolutely perfect or moisture would find a way behind it and condense on the steel walls. I believe that moisture should always have a way out, and if it got between the container walls and a vapor barrier it wouldn’t be able to.
Steve
Understood, thanks!!
Hi Steve, great work with your TinCabin. Congratulations… !!! I am trying to build one here at Uruguay, South America. My doubt follows…
How do you attach wood framing to the container?
Regards
Gaston
Gaston:
Pretty much the same way I attached the steel framing. Screw the bottom plate into the container floor with treated wood screws, and screw the top plate into the upper box beam of the container using metal thread cutting screws. As long as you use the correct length screws, neither of these methods will penetrate the outer shell of the container.
Steve
Hi Steve! Congratulations for the project design.
A question, I do not understand, how you fixed the steel frame on the wall of the container. The screw has penetrated the wall of the container? thank you
Juno:
The sheet metal screws used to attach the upper track DID NOT penetrate the wall of the container. The screws went into the upper box beam and only penetrated the interior panel of the box beam, leaving the exterior panel of the box beam intact.
Steve
Hi Steve, thanks for all the helpful info. My question is in regards to building codes and the related construction methods for shipping containers. You mention you are using 1-5/8″ steel studs, leaving your walls around 2″ thick with a finish I’m guessing. Where I live residential exterior walls must be 6 inches thick.
So my question is: Were you able to construct with thinner walls because this is a “cabin?” Is code different in your area? Or is this kind of a grey area?
Anything helps, thanks!
Ryan:
Even with the thinner 1-5/8″ thick studs, my walls are between 3-1/2″ and 5-1/4″ thick. This is because my studs are offset from the container walls, and that the container walls themselves are corrugated. While it’s possible to get the studs a bit closer (~1″) than mine, I did not have any interior ceiling framing so the upper box beam was exposed and I had to move my studs inward to enclose it. I was also careful to not have any studs touch the container metal and create thermal bridging.
In regards to code, it would be difficult for my cabin to meet the codes for a permanent residence. As a seldom occupied cabin it flies under the radar somewhat – as do most hunting cabins in rural northern Wisconsin.
Steve
Hi Steve, I’m looking to convert a single container into an office. Just looking at the posts above, I was wondering does the steel frame not move a lot without a support between top and bottom. did you put horizontal struts between the uprights? Would you ever have considered sticking an insulated board directly to the metal using some form of adhesive.
Thanks
Emmet
Emmet:
I would personally not use steel studs again except where they would be “glued” in place by the spray foam insulation. The thinner steel studs I used do not have the rigidity of a wooden 2×4 or 2×3. And even if you go with the larger steel studs, you might as well just use wooden studs as they are typically less expensive and easier to work with.
I have considered a hybrid approach where rigid foam board is glued directly to the metal walls, but I would also spray foam around their perimeter to prevent any moisture from getting behind them. In theory this should work, but I haven’t tried it myself. I would only do this if I absolutely had to save more money and didn’t mind the extra work.
Steve
You could screw z furring to the inside of the container and install a rigid insulation in-between the furring and then install drywall over it. Spray foam is best bet for thermal reasons but costs more. Also, steel studs are much easier to work with in my opinion than wood. Especially when you are trying to retrofit a space like this.
Steve:
I strongly disagree. First off, if you screw z furring onto the inside of the container you will be drilling holes throughout all of the exterior walls. Why would you ever want to compromise the weather-tightness of your containers?
Second, spray foam is not just best for thermal reasons, it is the best for vapor barrier reasons. It is the continuous and seamless vapor barrier created by closed cell spray foam insulation that makes it the best choice for shipping containers bar none. It is critical that moisture laden air never be allowed to reach the colder interior walls of a shipping container structure.
In regards to steel vs. wood, it probably has more to do with what you are used to working with.
Regards.
Steve
I guess I’m not familiar with the shell of your container. Obviously you wouldn’t want to compromise the integrity of your shell with framing screws. You could tack weld them if it presented an issue. If the z furring could be installed to your shell it would provide a solid base for cavity isulation and wallboard.
Spray will also help better for thermal reasons not just vapor barrier. Spray will fill all the nooks and crannies better than any other type of insulation gaining you thermal value.
I agree that it’s what your used to working with. I’ve been working with steel studs for 20 years so I am going to favor them. But I would still say with a non biased opinion that in a retrofit like this steel would be the preferred method.
Steve,
Great story and thoroughly appreciate your sharing of all your knowledge.
I am planning to do some house extensions using 2 x 40 foot containers. Following your advice, I will be using to frame the internals.
My question is in regards to Insulation. Spray foam is not that popular in Australia and so far I can find one company specializing in it approx 12 hours away. There are some do it yourself kits for sale which are quite expensive. My mate even owns an insulation business and can’t help me.
What is your best backup plan? What other alternatives would you use?
I live in a mild coastal temperate climate.
Cheers,
John
Hey Steve
Great Job on the article. I appreciate all the knowledge you’ve shared. A tip for you. When you install your windows and doors you shouldn’t install them tight to the framing, it’s better to leave at least a 1/2″ gap all around the window for spray foam insulation. It gives you a redundancy with your tape flashing air barrier, provides a thermal break, and also locks that window in.
Again great job, thanks for the info.
Tristan