Cob: Re: foundation materials - size

[Avalon Bruce]

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)