Caliche and Cob?

caliche and adobe dirt
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!

Update:

Thanks to Jim for pointing out The Center for Maximum Potential Building Systems, Caliche Report [PDF]

One Comment

  • Chris says:

    If you mix small part portland cement to caliche it will form a workable dough. When it cures in the sun it will be very durable! In my opinion much better without the sand. Good luck with your building!