I am a new cob rookie and I am filled with enthusiasm to begin a project. I would love to build a small cob structure using the bones of an existing steel pole barn with a poured concrete floor. Is it possible to build directly over the poured floor or is digging a trenched foundation still required? If I choose to use this area as an open patio retreat; building a garden wall instead over the existing floor, is the answer the same?
(be gentle, I'm learning and appreciate the help)