[Cob] Embedding metal

[Georgie Donais]

All,

In the ongoing saga that is the composting toilet/earthen building 
project in downtown Toronto, we have now been required to have not 
only an architect, but two engineers. The arch wants to build a metal 
frame to support the roof and then we'd cob up underneath; 
alternative roof support is the only way to get a permit. Four of the 
six supports are embedded in the cob.

Two questions:

Especially in an unheated building, it seems a questionable idea to 
embed metal support posts in cob, due to their different 
expansion/contraction rates. I can imagine strips of cob popping off. Comments?

He is requiring a bond beam around the top of the cob as it meets the 
roof, as per New Mexico's adobe building code. He is balking at my 
suggestion that it is not needed. Comments?

Any help would be appreciated.

Georgie
www.cobinthepark.ca