tour of cobville

[JRR]

For enduring an quake, a low/no mass struture would obviously be best.  No mass inertia to resist the earth's movement.  Think "tent".  With no heavy furniture.  But a tent in "open spaces", ... not under a raised portion of the expressway!  Nothing to come crashing down!

Years ago in a strength-of-materials class, we touched briefly on structures in siesmic areas. I remember one final idea concerning mass: There is an "ideal distribution of mass" in a structure, especially in multi-floored structures that grow upward and become more slender.  Best to put nearly-all the total structure mass in the walls ... and as little mass as possible in the floors.  With windows, doors and other openings ... our buildings usually don't follow this principle very well.  According to Wikipedia, cob material may lend itself to this principle for simple one floor buildings: http://en.wikipedia.org/wiki/Cob_(material).  But then, they mention 2 foot thick walls!

There has been some interesting information on public TV, concerning "siesmic resistive" building foundations using layered elements that easily slip so that the horizontal oscillations of earth do not pass upward into the building.  The first footing is poured and processed with a very flat smooth hard finish.  Then a covering of flat metal is applied.  Then another pouring of reinforced concrete .... finished smooth and flat again.  Another covering of metal ..etc, etc.  The final upper pouring of reinforced concrete is massive and rigidly coupled to the building structure.  This leaves the building free to stay in place while the foundation slips horizontally to follow the earth's movements.  When the system works as it should ...equal slip in all directions... the final location of the building (or, of the footing) will be very much as before the quake.

[RainDog]

I was watching the Haiti earthquake info and came across this emergency earth bag information.  Thought I would post a link here.

http://www.earthbagbuilding.com/emergency/emergency.htm

I like these tubes shown in the photo from the site you linked. The idea of earthbags seems, to my mind, at least, to be intuitively less likely to suffer catastrophic failure than cob or adobe. That's just my kneejerk guess, which may or may not be true. There are apparently different methods used to tie the bags together, from barbed wire to rebar, though I don't see anything like that in this photo.

Earth-tubes used rather than standard bags:


For a much less time consuming build, but with great insulative value and much the same look, yet with less likelihood of totally murderizing the inhabitant if it were to ever somehow tump over, how about something like this, made with thermoplastics:

http://www.youtube.com/watch?v=8Xb9PFF4MSc&feature=fvw

http://www.youtube.com/watch?v=GHljTXBAwXU&NR=1

Looks groovy enough. You could just TELL the granola crowd that it's cob. They aren't gonna check. Too stoned. Again.

 

[paul wheaton]

Perhaps it was not conveyed well in my video.  In which case, the error is mine and not that of the buildings.

These buildings were each (IMOO) and amazing piece of art + architecture.  I would  have to say that the quality of life of living in one of these is higher simply because of the aesthetic.   I have witnessed a lot of amazing forms of construction and I have to say that one would be hard pressed to come up with anything that can beat cob in this respect.  Some ferrocement structures come close perhaps - but cob still wins. 

Next up is to consider somebody that is currently unemployed and cannot find work:  building an outbuilding or two with cob is amazingly cheap.  It is time consuming, but if you have heaps of time and little to no money, this may be a good option. 

A very similar story for somebody that wants (needs?) to live on acreage, but cannot afford to buy a house on acreage.  This could be an option to buy some land far cheaper and then build on it. 

Also, the whole thing about how folks that are not very construction savvy can build with this stuff. 

There are upsides and downsides to using cob.   I'm not a big fan of doing it myself, but when I see a home built with it, I know how long it took to build it and can imagine people stomping mud day after day - and how when they are all done and they move in how they are ..... more tied to their home than I might be tied to mine. 

[paul wheaton]

part 2:

http://www.youtube.com/watch?v=j2YD4PenDxI