Cob: Earth Floor!

[Patricia Kerns]

Darel,

>From my experience, it is the clay/sand ratio that affects the shrinkage,
not the moisture content of the material.  Clay shrinks, sand doesn't.

> You mention the word "pour" below, but from my reading and it makes
> sense,the less moisture in the mix the less cracks and shrinkage upon
> drying.  You can always fill in small cracks though.


Can you elaborate on your comments that a rammed earth floor is the
strongest?  I have never heard anyone speculate that making the floor dry as
opposed to wet would make it stronger.  Have you actually tried this?  It
seems to me it would be much more labor intensive than trowelling on a wet
mix.  Also, what is your basis for the comments about lime?

> A rammed earthen floor would give you the strongest, especially if you
> gave it about a 14% slaked lime content.   The ash you use sounds like a
> good additive to.
>
> Darel