[Cob] Clay over concrete

[Barbara Roemer]

Jennifer wrote:
> I am building 
> on a 17 foot octagonal pad created by the previous owners, but am not happy
> with concrete and would prefer to install adobe over radiant tubing, rather
> than more concrete.

Clay (adobe) will move, expand, contract differently from the concrete under
it.  A friend has beautiful rammed earth, stabilized adobe (10% concrete)
tiles throughout her home, and even outdoors on the path.  It's sealed
inside, and not outside.  The continuity of materials and variation in color
is very attractive.  Rammed earth blocks or tiles which are stabilized would
assure you a crack free floor while adding just a small amount of concrete.
They can be mortared in place, which of course adds more cement.  Sometimes
living with what you have is a challenge.  There is a good article in the
current Fine Homebuilding re staining and finishing concrete floors.  Your
floor could still be kerfed....to look more like tile.

Barbara