I am in the process of beginning to learn about
cob with the eventual goal of designing and building a cob house for myself, and I have a question about the stem wall materials. It seems from what I've read that stone, brick, and urbanite (salvaged
concrete) are all acceptable materials for a stem wall. My question is whether or not there's anything inherently wrong with mixing these materials in the wall. For instance, a mix of stones and urbanite, or perhaps something layered (such as a few layers of bricks topped with layers of stone and/or urbanite, or even just different types of stone mixed together or layered (limestone and shale, for instance). I will be salvaging most of my materials, and it's hard to find sufficient quantities of any one material, but I want to make sure this won't cause structural issues or some weird problems I'm clueless about. Any comments about the advantages or disadvantages of various stem wall materials in general are also welcome. Thanks!
