Cob: Re: Earthquake country blues!

[Prof Joel]

Hi
	I love your saying at the bottom. As a neophyte cobber but someone who knows a bit of engineering, here is my thought: 
	No matter what else you do, don't build your cob house on a stacked rock foundation in Southern California. This is a wonderful foundation for certain non seismic regions, or for outbuildings. I live in Northern California where there is very little seismic activity, but I would not use a non-reinforced rock footing here. Shifting of the rocks can remove the foundation under certain parts of the wall, possibly with disastrous results. Make it a continuous footing of reinforced (gulp) concrete, or something that will not go away when (not if) it gets shaken. 
	As to how cob holds up to earthquakes, no real tests have been conducted that I know of, but there is historical evidence that a properly designed and built cob structure can perform very well. The foundation, roof and roof attachment are probably the places that need more design attention than the cob, assuming it is "good cob". The bigger it is the more careful you must be. Cob gets a lot of strength from the curves and its monolithic shape. Long straight walls that are common in "mansions" are scary. Plan well in EQ country. But you need to do this with any type of construction.
	As you say, the best way to find out is to pee on it.

good luck, and don't get scared away,

joel


At 10:25 AM 8/22/00 -0400, you wrote:
>
>Hi Folks,
>
>I live in Southern California and more and more am attracted to Cob as a 
>sound economical and environmental way to build our future "mansion". My 
>question is how well does Cob really stand up to a major earthquake. I see 
>all kinds of reference to Cob laid down over dry stacked rock foundations 
>etc. Just seems like a lot of work to risk a foundation like that? Even over 
>a poured foundation I have to ponder the merits. I would love to hear 
>anything at all positive for cobbuilding in our zone.
>
>Thanks
>Don Wells
>There are three kinds of men. The ones that learn by reading. The
> few who learn by observation. The rest of them have to pee on the
> electric fence for themselves.