[Cob] Rammed earth in ICF Forms??

[Sky Orndoff]

Hey Everyone!

I have been working on a conventional build alongside my cobwood project, and have come to really like Insulated Concrete Forms (ICFs) for their speedy, structural assemblage of a nice simple building (google superform).  I also like that they can directly hold plaster, and I like their thermal mass--insulation hybrid.  And I like how accepted they are with building officials.  What I don't like about the ICFs are the styrofoam itself and the concrete and those things' negative effects on the environment.  However, the durable, quite insulative, super-easy-to-construct nature of the forms makes them maybe worth it, especially if we can do away with the concrete. 


Here in Helena, Montana, it's quite dry, and horribly cold in the winter, and so I was wondering what you all had to say about the idea of filling ICFs with Rammed Earth.  As far as I know, Rammed Earth has approximately the same compressive strength as Concrete and similar (very little) tensile strength.  Its shatter strength is lower, I believe, than Concrete, and it can fail if it gets and stays wet.  Will I be constantly fighting moisture issues? Do you expect failure? Horrible and hideous catastrophic results?  Or did I hit on something smart? 


What I'd like from you all are ideas on testing/how to monitor moisture levels inside the forms, ideas on how to avoid moisture penetrating and accumulating inside the walls, and possibly ideas on ways to back up rammed-earth's strength.

What do you think?  Am I off my rocker, am I too apologetic to the constructionary-industrial complex, or is this an idea worth exploring?

Thanks a lot for your feedback!

Sky

www.earthartbuild.wordpress.com