Caliche and Cob?
Ryan asked a question recently, in the message board, about using Caliche in cob. I too have a layer of caliche in my soil, about 3 feet down under the ‘adobe dirt’. Caliche is a form of calcium carbonate that cements together other materials like gravel, sand or clay. It’s generally found 3 to 10 feet under the topsoil in arid or semi-arid regions. The term caliche is Spanish and is originally from the Latin calx, meaning lime.
I wonder if it could be used as a replacement for sand? Pulverized caliche could add color or brightness to your finish plasters; kind of a natural lime or whiting. I haven’t experimented too much with this material as an additive to cob. I doubt it would have a negative affect. Let us know if you have experimented with caliche and cob!