[Cob] Stone Haven

[Henry Raduazo]

	The problem is that doing tests costs lots of money which Cob Cottage does not have and meaningful tests are impossible. Note: A meaningful test would be to build a structure with steel and then test it after 30 years of exposure to the weather. That would mean something but how do you do it? The Alpha testers in this case are the people who are getting talked into building these steel reinforced cob structures based on short term testing and/or speculation. Americans love steel and concrete! The Alpha testers or their descendants will find out the results of these experiments when their structures experience earthquakes twenty or thirty years from now. I think the best we can hope for is that the steel will not weaken the structures. 
	I used galvanized nails as light weight hurricane ties to anchor rafters in a wall because I heard that when steel nails were used to anchor wood window frames in cob they rusted to nothing because inside the wall there was not enough moisture to rot the straw or wood, but plenty of moisture to corrode out the nails.
	I have built cob with shredded wood in rototiller cob instead of straw. The wood fibers are many times stronger than wheat or rice straws. I have also incorporated strips of split bamboo into structures. It bends and follows the curve of the wall, and has fantastic tensile strength. How would I ever go about proving it is better or worse than regular straw? My test has been running for three years and nothing terrible has happened that is all I can say. I suppose I could remove some of the fibers from the wall and see if they still have superior tensile strength.


Ed

I have a photo essay on the wood fiber straw and pictures of the cob walls with embedded rafters if anyone is interested.

On May 9, 2012, at 4:16 PM, dhowell at pickensprogressonline.com wrote:

> Janet: The walls will have rebar as that has been proven to make cob stand up even better in an earthquake.
> 
> Damon: This doesn't sound legit, it really doesn't. I believe they're not taking into account the different expansion rates of steel and clay and how that will cause clay to shrink away from the rebar, letting in moisture to rust it away, then you're left with a cavity. Yeah, that sounds really strong. Sounds to me they're taking what they know works with concrete and adapting it to clay, it's not the same material though. And you're right, this is gonna be what the codes require: weak buildings because of the lack of foresight and knowledge of natural building materials. I wonder where the Cob Cottage Company is in all this "cob code writing" stuff? They probably have much more to offer than most engineers, because they've been improving cob in earthquake-ridden zones since the 80's. As a recall their book said to not use steel. But whatever, I guess I don't much about it myself. I'm just using common sense which is what most cob enthusiasts do.
> 
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