Preventing Buckling.

[Alexlebrit]

Reading the story of the bucklig roof I immediately wondered

What is the solution?

Is there a simple solution for the DIY-er? Should one automatically think weld in extra strenght? Or could other materials be used, wood joists for instance?

I'm wondering because in my early stages of design I'm thinking about cutting out whole sides and I'd rather not have a bendy house in the end.

[sailboatescape]

I don't think there is a single "solution".

One thing that I don't believe was pointedly stated in earlier discussions is there can be buckling without any load and that has to do with stress relief when the skins are cut out vs. buckling that could be associated with loads on a modified container. The heat of welding introduces expansion and then as the metal cools and shrinks it pulls and stresses the steel (original manufacturing of the box). In cutting openings, that stress is relieved and can manifest itself as buckeling. I suspect that is what happened on Karen's boxes.

A box without any holes is a structural unit and when you cut holes in it you weaken it. However as a whole unit it is designed to carry almost 50,000 pounds (20' container). Since most conventional houses are designed for things like 40 pounds per square foot load which is only 6,400 pounds, it is obvious you can cut some holes without compromising the strength for your intended purpose and the container is not going to sag or bend or otherwise deform.

So back to your question. Whether or not you will get buckling when you make cut outs depends on where the stresses are in your container and where and how big you cut the holes. David Cross mentioned that some weld braces or use chains etc., to hold the frame members in place when modifying containers, but most DIY will probably take pot luck as they cut their holes. The containers are designed to carry that 50,000 pounds I referred to in a 20' container being supported only on the 4 corners and most builders will give more support with some type of foundation. Whether or not you need to add braces or supports when you start cutting holes will depend on your total design. However, I suspect that the containers are forgiving enough that a little common sense will go a long way.

[Alexlebrit]

Thanks for that, it does seem a bit of a pot luck thing, which could I see be one off putting thing about using containers. I'm also wondering if there's less or more chance of buckling in new vs used. Perhaps at certain times in a containers long hard life they've been subjected to loading which has caused twisting, so that the four corners aren't totally aligned anyway. Cut holes in it and oh look buckles.

The rough SketchUp is shown in my OP, with the floor plan of the four containers being aranged just so:



One of the four (dining) one in the above picture has both sides completely removedand filled with glazing, the other three will have one full side and the doors removed.

Touch wood, we'll avoid the twist, my guess is that I'll probably need some form of vertical bracing for the open sides, and probably additional (legs) between container and foundation.

Now how to work out how to install underfloor central heating.

[eamesdaedelus]

I FINALLY found a pic of one of my all-time favorite container based projects.



As you can see the sides of the top containers have been completely removed. On the interior space, there are two columns placed over the lift slots (in the bottom side beams) to brace the 20' spans. Also of not is the cable bracing at the corners of the glazed facade. This is in lieu of the columns, although I think the glazing is set in steel angle frames that will provide a modicum of strength.

there are an amazing amount of great construction pics over at:

Freitag's Flickr site
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512.619.6962

[eamesdaedelus]

more container images:

































Edited to fix code - Ed.
_________________
designSTUDIO
box 684742
Austin, Tx 78768

512.619.6962

[Alexlebrit]

Hmm I feel so unimaginative now - thanks for those

[SchwarzStudio]

eames,

can you identify that 6 x 20' (three high, three across the top) that you posted. it's quite a looker. thanks for posting the images.

[eamesdaedelus]

It is my fave. It is called Orbino, and it is by Luc Deleu, who also did all of those crazy artsy container sculptures I posted. I first saw it in a book called "paraSITE :: PARAdise" which chronicles a prefab exhibition in holland.

I think it clearly shows the inherent strength of the boxes. The interior of those top three boxes is a 20'X 24' gallery space with the full wall of glass looking out over the landscape. There is an exterior stairway attached to the back of the three high containers that allows access to a standard sized door.
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designSTUDIO
box 684742
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512.619.6962

[etb]

A Google for Orbino finds

http://www.orbino.nl/

Alkmaar is in the Netherlands, about 30km NE of Amsterdam.

My Dutch is terribly rusty (I never knew much and haven't used what I did know for over 20 years) but the message on the back of the truck says something like "Moderate your speed, art in progress/transport/something".

Ed.