I am writing because I am absolutely so excited about building a cob outdoor oven, then a small placehouse for my daughters, etc... my husband and I will be building this first time... so please, any advice is warmly welcomed.
We live in Prescott, AZ where its hot and the earth here has a ton of clay. We wanted to mess around just to see how strong it was. So after a few beers, mixing our soil, sand from the dry river bed, straw and water, we mixed it up good and placed it into a earthen pot as a holder to our tiki torch. The next day it was hard as a brick. Could you tell me if I have to buy clay here in Arizona when there is already so much of it in the soil? I realize now how the Native Americans built their Adobe homes and Pottery. Its beautiful and very cool! We need all the advice we can get! Also, how would we find out if its even permissable to build a cob home. My understanding is most of the county officials are ignorant to this type of building in most places and dont honor permits for Cob housing
Count yourself lucky! Most parts of the country have some sort of claylike soil that can be used for cob, perhaps with additions, but you appear to have all you need right there. There is a good reason cob/adobe was so common in your part of the country - conditions and resources are just right for it.
While I have no direct experience there, I have heard that at least parts of the Southwest or West have enlightened codes as regards cob or adobe. So I suggest asking local building officials about it, or looking up the applicable codes if possible.
In NM, at least, the state building code does have provisions for adobe. I bet that AZ does too.
So, right away, get used to calling it "puddled adobe" locally and "cob" online.
That will help you get people comfortable with helping you. They know adobe inside and out, and they have maybe heard of puddled adobe. If not, it's easy to explain. You just let the mix harden in place on the wall instead of hardening on the ground and then stacking. Simple.
Online, it's "cob" because of the UK and now Oregon traditions. But around New Mexico, "puddled adobe".
If you look closely at this tiny ad, you will see five bicycles and a naked woman: