can anyone offer help w/ following two queries: 1) can caliche rocks/boulders be used for setting DEEP foundations (2-2.5 ft. deep) to build small, cob structures upon - approx 12 ft. x 15 ft. 2) how LARGE a structure can one build using cob -- i need a 14 ft. x 24 ft. 'activity' room build adjacent to two of the above 'bunkhouses' thanks. avalon (list lurker for sometime)