[Cob] Wall building problems

[Mark Thomas]

Hello from Southwestern New Mexico. 

Attempting to build a small cob building on my property south of Deming. The cob dries fast in the dry, hot and often windy weather. I have not been able to work the next layer into the previous while it is still plastic yet firm enough for support. Tried covering with tarps and placing wet hay on the wall. 


Re-wetting the wall is difficult.  The semi-dried cob does not seem to accept water and soften up.   Have tried leaving holes in the top of the wall to be filled with water.  Maybe it is the expansive, montmorillinite clay?

Any cobbers out here? 

Any suggestions?


One good discovery. Crusher fines from the local gravel pit (about 3/8 minus). Cheap and a good additive to high clay soil that contains lots of fine dune sand. 



Mark