Bill Sitkin says, "At the heart of recycling, for me, is a great love for this planet and the awesome natural systems that support life here. I have always been a 'dumpster diver' and developed a used building materials and deconstruction business known as The ReStore in Crestone, Colorado. I look forward to your questions on anything about recycling materials or deconstructing buildings."
C: There are estimates that there are over 70 million empty shipping containers in the USA clogging our ports, and 40’ containers can be bought for really cheap ($1000 - $2000 each). They are structurally very strong, can be stacked, and the new heat reflective coatings available today make the containers a viable option instead of an oven.
Q: We have a lot in the south-eastern side of Mexico, near the ocean. It is a fairly remote area at this time and power and building/worker's etc are not in great abundunce. I think the container building may be a great alternate. Just a couple of question's: How do they fair in the hotter area's? Also, we were hit by Cat 5 hurricane a couple of year's agoand I understand these may be a good structure for these area's? And finally, the cost to refit and finish a container in comparison to regular construction cost's?
A: (Kelly) Steel container homes need to be insulated to be comfortable in practically any climate, so yes this is essential in that area of Mexico. The containers themselves are virtually indestructible, so they should be able to handle hurricanes pretty well. Of course large areas of glass, or other parts of the structure that may be added onto it might be more vulnerable to winds.
Cost comparisons are bit difficult to make, especially in Mexico where labor tends to be cheap, so new construction can be fairly economical. The container(s) would need to be purchased, transported to the site, and then retrofitted to become a home...so there may not be much difference cost-wise in the end.
Q: We are seriously considering building a home from shipping containers. One thing that concerns us is how to insulate it. The 'finished product' will have a traditional home look, with hip roof and siding of some sort. We are thinking that some type of spray foam polyurethane insulation would be good for the inside, but what about the outside? Since the house will have siding, we assume that ceramic paint would be pointless. what would you consider to be a good insulator for the outside walls, if any is required?
A: (Kelly) As long as you are going to put siding on the outside anyway, I suggest that you also add insulation there. The SG Block folks use a commercial insulation panel material that you can see being installed in the middle of this article.
Q: I really like the idea of using heavy strong steel boxes as the structural framework of a home, and it seems to me that containers would have one massive advantage - once they are in place and welded together (with plates welded over any gaps/joints, etc.), we would have a completely dried in and structurally sound box in which to work. Anyway, as much as we like the utility of containers, they lack a lot when it comes to aesthetics. We certainly do not want our house or even our outbuilding to look like containers when were done, so I'm wondering about using earthbags as an exterior. It seems to me that the earthbags would nicely compensate for the lack of thermal mass in the containers (insulating ceramic paint (assuming it actually does work) can only do so much, while the containers would remove some concerns about structural rigidity with an earthbag structure (particularly in the mind of a building inspector). Does this seem like a reasonable approach to you?
To consider the practicalities of this - how would you tie the earthbag exterior wall to the steel wall of the container? I was thinking that it could be done via the barbed wire - either by welding the wire at points to the container walls so that your wire in between bag layers was tacked to the wall every so often, or by attaching something like D-rings to the container walls and running the wire between the layers of bags through that every so often. Does that seem reasonable? Do you think that exterior buttressing of those 40' long vertical walls would still be required? Without buttressing, I'd be a bit concerned about the potential "pull" of the earthbag walls on the steel side walls of the container. Also, I know that in brick veneer construction, there is nearly always a narrow air space between the framing sheathing and the brick - would something similar be required in this case, or could the earthbags be brought flush to the container sides? On another front, do you think it would be possible to use earthbags to create a roof surface on top of the containers? I'm picturing something very much like a typical adobe structure, with a parapet and a flat roof (well, apparently flat - it would naturally need a crown for water runoff). What sort of material would you recommend as a finish for such a roof - concrete stucco? Or would it be better to just pour a (relatively thin) concrete surface on the roof?
A: (Kelly) Much of what you say about containers is true. They do have to be insulated in order to be used for comfortable habitation. I have my doubts about the insulative paint being sufficient for the job, especially since I have read rather disparaging reports about the efficacy of this paint over time. Another approach to insulation (besides commercial foams and rigid boards) might be to use earthbags with an insulating material as fill. Rice hulls, crushed volcanic stone, perlite and vermiculite are possibilities for this.
Attaching the bag wall to the container should be fairly easy to do, either with what you suggest or possibly running loops of wire (it wouldn't have to be barbed) around one entire bag and through an eye welded to the container. If this were done on a grid of about every 4 ft. (both vertically and horizontally) I don't think that any buttressing would be required.
With brick veneer, the air gap is for breathability. Steel containers don't breath at all, which is another reason to put the insulation on the outside; otherwise the cold steel would likely condense moisture on the inside. With earthbags, I don't see the need to leave such an air gap.
Just how you treat the earthbag wall depends on various factors, especially how you design the roof over the building. Probably the best thing to do would be to design the roof with a large eaves, so that the earthbag walls are protected from the rain. If this is done, then the earthbags can be left breathable with an earthen or lime plaster.
I would advise earthbags on the roof only if they are covered by another roof and are there merely for insulation. I would not advise a flat roof and parapets, as this would increase the likelihood of problems and maintenance issues over time. You do need insulation on the roof (even more than the walls). If you really want to proceed with a flattish roof, then perhaps some combination of a moisture barrier (like EPDM) and concrete would do.
Q: My wife and I are starting a project for a small Montessori school in Ensenada, Baja Califonia. We are looking at inexpensive building alternatives with a recycle/re-use principal in mind. We have decided to use reclaimed ISBU shipping containers, but we are now faced with insulating these containers. We would like to keep the recycle/re-use principal, but also keep costs low. I am considering doing a papercrete formed wall, about 4" thick, and 4'x9' that would be poured flat (tilt up), the form would be made of galvanized steel studs, and would be used to attach the formed wall to the container wall/frame, from the interior. Would this size/thickness of a wall be light enough to be carried by two/three people?Iis there any way these could be formed vertically in place?
A: (Kelly) While in theory what you suggest might be possible, I can foresee some difficulties and reasons that it might not be your best approach. Such PC panels would have to be formed horizontally, outside the container and thoroughly dried before being moved inside. 4" of PC provides only about R-10 insulation at best, which is not much to withstand the radiating intensity of hot metal. Add to this the fact that these interior panels would be diminishing space that is at a premium and needs to be preserved for other functions. I think that a much better approach to insulating shipping containers is from the outside. In fact I have just been communicating with a man who is currently living near Puerta Vallarta, MX and is contemplating doing something very similar with shipping containers. Some years ago he started a school there to assist kids who work at the local dump, recycling trash for a living (see www.childrenofthedump.org ). He suggested getting the kids to save the styrofoam that accumulates, crushing it into particles, filling polypropylene bags with this material, and stacking the bags around the container for insulation. Even the bags can be used or recycled ones. To further protect the bags (which need to kept out of the sunlight) and the containers themselves, we discussed the notion of covering them with plastic (maybe a pond liner, but it could be an old PVC billboard or even heavy polyethylene) and then backfilling or covering the whole thing with soil...which could be planted with local plants that grow there. Or, the poly bags can be encased with stucco netting and plastered to make the building look like any other Mexican building.
Q: What are the most common, or some of the different types or styles of, foundations used for container homes.
A: Most container homes that I have seen have been set on standard continuous concrete foundations, but this might have been a requirement of the local codes. There is no reason why they couldn't also be set on concrete piers. There are some pictures of various foundations at here.
Q: I am interested in building a house out of shipping containers. Have you heard of people covering the container with metal lathe and concrete stucco? Would you have any environmental/health concerns using that covering method? Also, one blogger warned that the floor is soaked in pesticide. If that were removed and replaced, do you think that the harmful fumes would no longer be dangerous?
A (Kelly): I have not heard of anyone covering containers with stucco, although I'm sure this is possible. My main concern with doing this would be the fact that this would add no insulation to the wall or roof, and so the heat and cold would still penetrate inside very quickly. If the container and the stucco were isolated from each other with a good layer of insulation, this would be much better. I also had heard that the original floors might be toxic, so this should be carefully evaluated. If the flooring were removed, then it is unlikely that those toxins would remain, since metal does not absorb such things.
Q: We are looking to build a 2500 - 3100 sq. ft. modern, hurricane resistant house on a Florida barrier island. Looking for designer, suggestions, etc. The structure will have to be on 12' pillars with the pillars preferably extending without interruption through to the roof. Will also need an elevator to service all floors.
A: (Kelly) A hurricane resistant house built on pillars obviously needs to be well engineered for these very specific requirements. One idea would be to use shipping containers that are welded together and placed on the pillars. Besides an elevator, I would advise an auxiliary stairwell, or else you could be stranded without electricity!
Q: I am considering building a house from containers, but was curious how you do electric outlets and plumbing throughout the containers? Do you have fake walls?
A: (Kelly) There are a variety of ways to install electrical and plumbing in a container home. Some such homes would have interior wall panels, so these features could be hidden behind these, as is normally done with wood-frame construction. Another possibility is in conduit placed in inconspicuous places, or in special chases that are built to accommodate them. Also, some of these can be hidden under the floor or ceiling, depending on the design.
Q: If you remove all side panels from a shipping container and leave the corner supports, will it still be able to hold up several containers placed above it? The design I am looking at calls for a big open living space with 4 - 40' HD containers place side by side. The middle two preferably won't have any sides, making this section completely open. This would be great for a single story design, but I am thinking about the second or third story...
A: (Kelly) There is at least a partial answer to your question in the second picture down in this article. You will notice that the container that is suspended by the crane has a completely open side, but the wall that was removed has been replaced with vertical support spaced about 4 or 5 ft. apart (I'm guessing), and it appears that the container that will match this wall once it is in place has a similar arrangement. This would suggest to me that the engineer on this project felt that these supports were necessary to preserve the integrity of the structure. Another approach is pictured at the tenth photo down in that same article, where you can see an open section has been removed from the side of one container leaving a frame of the original wall intact which would serve to create a type of reinforced beam, or header, across the top of that wall. I suggest that you check with a qualified engineer before committing to any particular plan.
Q: I need your professional opinion regarding tolerable temperature recommendations for container homes in Haiti. What would have to be done at minimal cost for container homes to withstand the heat of Haiti? I am thinking the piling of dirt and stone on the roof and as white a coating on the sides. What is your professional opinion?
A: (Kelly) The best would be to pretty much bury them with dirt on the sides as well, but this is a lot of work and may be costly. A layer of plastic to keep moisture away from the metal would be good. White paint would also help, but I don't know if it would be enough to make it comfortable inside. Other ways to insulate the structure is with styrofoam, or possibly bags of rice hulls or volcanic stone, or bales of straw if available.
Q: Was hoping you could tell me how far a 40' container can be used to span? ie between two other containers to give me a large open area below. Using two containers on the sides and 5 for the roof could I have the side containers 35' apart.
A: (Kelly) I do suspect that an intact 40' container could almost span its entire length without deflecting any more than perhaps a quarter of an inch...but I am not an engineer, so you'll need to verify this with a qualified engineer.
Q: I'd like to put on a carport, but would love to be able to use something recycled for the roof. Must be able to sustain central PA winters including ice and snow. I want to do a shed roof roughly 20 x 15 feet with a shallow pitch for drainage to create a carport. I have no building experience, but what I figured would happen would be they would bolt something to existing building and run out 20 feet to attach to posts of 6 x 6 weather treated lumber set in concrete. I assume they would use 2 x 4 covered with plywood and then covered in shingles to complete the roof. I have read about people recycling storage containers into modular homes and that sort of concept was appealing to me. I was wondering what might lend itself for reuse as a shed roof. I didn't know where to look for ideas about suitable materials and hoped this website could point me in the right direction.
A: Actually, shipping containers would be wonderful as they are collecting at the docks and need somewhere to go. Two containers side by side and 20' long would give you 16' x 20' and you would not really need a roof. These units are weather tight and the inner walls can be cut to give more room inside. I have discovered over the years that by driving around your local area you can spot some interesting materials that have been neglected and all it takes is a call or two to locate the owners to ask permission to acquire them. Our local land fill even lets us harvest materials that would otherwise be buried.
Harrisburg should have a local used building materials recycle center that may yield just what you need. If you need to go thru the permit process your choices as to what to use may be limited due to county regs. Check that out first unless you live pretty rural with no threat of being found out.
Q: I am an architecture grad student at the University of Utah, designing a school and orphanage for Haiti. I would like to use shipping containers in my design, but worry about insulating them, what type of roof to put on, and if it would be an easy enough project for the Haitians lack of machinery! I would appreciate any and all help you could give me!
A: (Kelly) I know that others have been designing and likely actually utilizing shipping containers for housing in Haiti. It is a good idea in that they are extremely resistant to practically any kind of hazard. They would need to be insulated in that climate, and I can think of several ways to do this. Commercial rigid panels of insulation could be used; these provide a high R-value in just a few inches. There are various types of spray-on insulation materials, and in one instance I saw this done on the outside of a shipping container. I have heard of insulating paints that might work, and if so, this might be the easiest solution. The container itself could be either buried in the ground or earth-bermed to provide a thermal barrier. Most of these solutions do require more industrial materials and/or equipment that may be difficult to source in Haiti.
Q: I am trying to figure out how to bury a shipping cargo container. I have talked to many who have had them collapse. I was hoping you knew some one who could give us pointers on how to make sure the static pressure does not collapse it.
A: (Nabil Taha) Shipping containers are very strong for vertical loads. They can be stacked up to 9 containers high.
However, the vertical load must be at the corners only where there are strong steel tubes. NOT on the sheathing/skin/corrugated sheets of the roof.
In your opinion - how much bracing / strengthening would I want to do? If we are using a 20 foot, would every 2 foot work, or does it need more? If you were doing this would you use the angle iron or tubes? I need to bury it completely but will only be using 10 inches on top.
The strengthening for the shipping containers depends on: 1-Depth of embedment, I know in your case it is 10 inches. 2-If underground water will be present or if it will be drained by a French drain or other means. 3-If you will have traffic above it, like vehicles. 4-Soil type at your site. With all these variables, you need a design for your case. Also, shipping containers are not designed to take any lateral/horizontal load on the wall sheathing/skin/corrugated sheets from the soil. So, when you burry a shipping containers, you must strengthen the roof sheeting and the wall sheeting with structural members such as steel angles or steel tubes. Also, do not burry then too deeply; the deeper in the soil they are, the higher the soil pressure on the skin/sheeting.
Q: My Husband and I want to build a container home, essentially an off the grid for a self sustainable farm. Before buying land I need to find out what counties in California, New Mexico, and any other states allow container home construction. If you have a list that would really help us. I found a few net news/magazine articles but so far only two counties in California allow it.
A: There is an e-book that you can buy that lists all of the counties around the country where building codes are not enforced, and you can order it at here. Actually, you can probably build a home using containers in most places, but may be required to have a structural engineer sign off on your plans.
Q: I am the Vice-President and Chief Philanthropic Officer for a non-profit organization called the Kroo Bay Initiative in Denton, Texas. We are a brand new, student-run organization creating sustainable development solutions for the Kroo Bay slum in Sierra Leone. After many hours of research on shipping containers and their sustainability, I stumbled upon your site. As a student at the University of North Texas, I am majoring in International Development this December. I can see that these shipping containers are becoming an ideal solution in disaster relief situations. I am contacting you because I would love some advise. I would like to pitch the idea to our board of directors to create sustainable housing in Sierra Leone; specifically in Kroo Bay for a community of 6,000 people. Is there anything you can tell me about the process, and the steps you have taken to make this possible? How did you begin, and what expenses are involved?
A: (Kelly) My involvement with shipping container homes is only as an interested bystander, much like yourself. I don't have any direct experience with them, but I do realize that they have great potential for residential development, under certain circumstances.
This could be an especially sustainable approach, especially if there is an abundance of containers stacking up at the local ports. I don't really know what the situation is in Sierra Leone, but I doubt that they do a whole lot of importing of commodities sufficient to have surplus containers there. Of course these can fairly easily be shipped from other localities, even completely outfitted and ready for habitation, but this might be rather expensive, both economically and ecologically.
My other concern about using shipping containers there as houses is the climate. My wife once spent a summer in Sierra Leone when she was a student, doing development work, and she said that it is quite hot, rainy and humid. A steel container home would have to be very well insulated and ventilated and preserved against rust to be at all habitable, and of course this might add to the cost.
Then there are the cultural issues to consider. Is this type of dwelling something that the people there would actually embrace? Too often well-meaning foreign developers will impose "improvements" on people whose cultural outlook is quite different. Sometimes they will be gracious and accept their gift, but afterward the space is simply not used.
Q: I'm a graduate student at the University of Arizona. I'm currently compiling information for my thesis project. I am looking at designing a low cost, energy efficient modern hospital in a remote region of central Honduras. I'm interested in phase construction through cargo containers, since this will be developed as funding is allocated. As you may know hospitals require specialized HVAC, among other components, therefore I was wondering if you knew of any case studies related to building health care facilities with cargo containers.
A: No, I have not heard of any studies or actual working units set up for hospitals. I think you are on the right track though as shipping containers would be cost effective, easily converted and easy to move if needed in different parts of the world. Hope this all works out.
Q: I am a 21 year old filmmaker and environmentalist...which I call now, just being a human. My friends and fellow artists are looking into leasing some farm land from a friend of mine where we would like to set up a co-op farm/educational arts centre where we can provide lodging for travelers workshops and performances of film, theatre and music, along with inviting youth groups to come and experience art and farming together. We want to start by building ourselves a green home. Unfortunately we have no money. We feel confident that we could get some cash, along with bartering but my question is what routes are there to build eco habitats for low costs. One of the idea's I had was buying a train freight bin, and converting it. Any tips or suggestions you might have would be very appreciated.
A: Shipping containers are great for shelters and there has been quite a bit done with them from homes to storage. There are many websites that feature these units. There are also underground homes that range from basic to outrageously expensive. One technique Kelly and I have seen is to mound up soil to the size of space you want, lay out re -bar, chicken wire and metal mesh over the mound, apply cement to create a ferro cement roof and then dig out the soil from beneath the roof to any depth you like. You may want to plan for skylights during the roof making process. You may want to consider a basic strawbale structure. Do a search for emergency strawbale shelters.
Q: We are in the concept stage of a shipping container house. We are considering insulating the structure with polystyrene/styrofoam and covering the insulation with cast concrete. Is there any president or best practice for doing this that you can refer us to?
A: (Nabil Taha) I don’t see a problem with what you are doing. However, we used spry foam insulation before on the inside surface of the container and cover it with sheetrock.
Q: I'm looking into building a five 40ft side by side container home. I was thinking of cutting all the side walls out and then fitting out the "shell". Would bolting the containers together at the top rail ends be sufficient reinforcement to be self supporting? Sheet metal roof.
A: (Nabil Taha) No, the wall’s top rails cannot span the 40 feet. In some projects we did, the rail was able to span only 5 feet without the wall underneath. So, you need a beam at each of the locations where you want to remove the walls, at marriage lines. The size of the beam depends on the roof live load specified per code and the snow load, if any, specified by your local building department. I recommend that you retain the service of any local licensed engineer.
Q: I am cofounder of a non profit in Guatemala called Resplandece Guatemala. Our focus is in providing opportunities to street children so they can have a sustainable and holistic opportunity of growth and grow to be someone who can bring change to the country. Right now we are working on a home for kids and I stumbled upon with the container houses and am interested in finding out more about it, costs (if it is cheaper than regular building) and possibilities of your help. We have been promised with a piece of land where we will be able to build our own facilities and stop renting, so we can use the rent money to feed and school more kids. We want the home to be built in such way that we can be as green as possible (solar energy, rain water savings for recycling uses, and so...). Guatemala is a volcanic country, so we are in constant threat of earthquakes. Would the container houses be strong enough?
A: (Kelly) This sounds like wonderful work that you are doing. Recycling used containers into housing can be a very ecological approach, especially if the containers are available nearby for a good price. They can certainly withstand any earthquake activity. The main need for making them comfortable is some form of insulation. There are many clever ways of combining them into interesting spaces; some concepts are shown in the article I wrote. At the bottom of that article are some pictures of an entire school that was built in Guadalajara, Mexico. It might also be possible to bury, or partially bury, a container to take advantage of the stable temperatures underground, which are likely quite comfortable in that region.
Q: We are considering building a container house from two forty foot containers and are researching cladding/insulation options, in your opinion would it be possible/advisable to sandblast the paint off and have the bare steel develop a patina and leave them bare metal and insulate on the inside? This would be in a dry and very hot climate.
A: (Kelly) It does seem possible to treat the exterior of shipping containers in that way. The disadvantage of this approach is the loss of interior space by adding insulation there.
Q: We are about to build a shipping container house in Sydney and are wondering if Papercrete will be a suitable insulation/wall covering... We were thinking of spraying the steel walls with insulative ceramic Supertherm paint then papercrete spray to a desired thickness and having it smoothed out when its wet to make it look like render... What do you think? Would that work on steel walls? Would there be a moisture issue? We are getting the coreten containers and removing the paint to let them rust and get that gorgeous colour to them.
A: (Kelly) Recycling shipping containers is a great way to go. I notice that Sydney has a rather moderate climate, but you will obviously still need some degree of insulation to be comfortable. If you leave the metal bare on the outside, then the inside would be where you would place the insulation, but this leaves the conflict of also trying to conserve the limited interior space. Papercrete only provides about R-2 per inch, so even with the ceramic paint I would expect that you would need another 6 inches of papercrete to be comfortable. If you feel you can afford this much space taken up with the PC plaster, then it might work for you.
But there is also the hurdle of getting it to cure (dry out) inside an impervious and closed space. I expect that you would need to open up every door and window and use fans for several weeks before the PC might be dry. Then you would also need to make sure that the interior of the house is well ventilated to make sure that humidity doesn't build up to the point that it condenses on the cold steel surface and begin to soak into the PC, which might promote the growth of mold.
In order to get the PC to stick to the walls of the container, you will likely need to attach some mesh of some sort for support and solid attachment.
If I were considering such a project, I would prefer to insulate the structure from the outside, thus preserving the optimal interior space and eliminating the other challenges mentioned. Better yet, I would consider burying the containers to create an underground home. In Sydney, the year-round underground temperature is about 67 degrees F., a very livable temperature, so you could be comfortable without any insulation or energy input whatsoever!
Q: Recently I have been giving some consideration to Shipping Containers for home conversion. At the same time I am really wanting to go with an Earth Shelter Home. I would like to bury 4 containers side by side using Earth Bags on the two outer sides, however; I am unsure as to the roofs being able to take the stress of the soil on top. It seems to me that since each container being only 8 ft. wide, they would be able to handle the weight. Have you heard of this being done before?
A: (Nabil Taha) Shipping container area stacked on top of each but they are in contact at the strong corners only. When you bury the containers, the weight of the soil is loaded on the roof metal deck of the container that is not designed for this weight. So, the roof and sides of the containers need to be strengthened. Please check with a local licensed engineer or with PSE at www.structure1.com.
Q: I am building a home out of 40' shipping containers (6) and was unsure about the removal of the walls, what kind of beam would I need to support after making an open floor plan of the span of 40'? I will also be setting a top floor with shipping containers on top.
A: (Nabil Taha) A steel beam W12x50 with steel posts 5x5x3/8 at 10 feet on centers may work. However, you need to consult with a local structural engineer to make sure that the above beam can support the second story.
Q: I recently purchased and placed my container. I am ready to start designing and building. What is the best way to attach siding to the outside without putting holes through the metal which could potentially leak. Secondly is it best to attach insulation to the inside our outside walls. Lastly, what is the best way to attach fixtures and outlets to the interior again without compromising the envelope?
A: (Kelly) There are commercial building adhesive products that would likely serve to glue panels or nailers to container walls to avoid the need to use screws. I think it is better to have the insulation on the outside so that the metal won't get too cold and condense moisture. Also, this would tend to keep the interior space from being diminished. I have seen it suggested by contractors who specialize in container homes that it is possible to use a type of ceramic coating that will actually insulate the walls by simply painting them (see www.supertherm.net for one possibility). There are many ways to approach such a project, so the exact way to install wiring and fixtures depends on how any interior wall materials might be used.
Q: I have been considering using shipping containers, & I would like to build into a hillside on our 5 acre property east of Yakima, WA (very dry country). I have an acquaintance that built a 2-container home, used 4" polystyrene insulation, heavy plastic moisture barrier (similar to swimming pool liner) & covered the top with reinforced 6" cement. He covered that with 3' of soil. He put 18" of gravel between the side insulation & soil. That was 8 years ago, and they have been living there every since. My question: where do I find any information on doing this on a larger scale, such as 4 45' High Cube containers, with 2 more for a garage. I have the room, climate & location...I just need more information on doing this. I know I need a structural engineer to tell me how to reinforce it. Any ideas or places/sites to go to help me?
A: (Nabil Taha) Shipping containers are very strong for vertical loads. They can be stacked up to 9 containers high. However, the vertical load must be at the corners only where there are strong steel tubes. NOT on the sheathing/skin/corrugated sheets of the roof. Also, shipping containers are not designed to take any lateral/horizontal load on the wall sheathing/skin/corrugated sheets from the soil. So, when you burry shipping containers, you must strengthen the roof sheeting and the wall sheeting with structural members such as steel angles or steel tubes. Also, do not burry then too deep; the deeper in the soil they are, the higher the soil pressure on the skin/sheeting. We can help you with the engineering at www.structure1.com.
Q: Could truss ends sit on the top of the shipping container? I'm guessing only at the ends and the middle would need to have some sort of beam for trusses to sit on.
A: (Kelly) I think the the trusses for a lightweight roof could likely rest on the container walls without a problem. If there is any need for additional reinforcement it would be toward the middle since the ends can support a whole stack of other containers.