[Cob] sound proofing

[Raduazo at aol.com]

Sabrina: I have only built a very small storage building for a children's  
playground, but the technique I used might work for a larger structure.
    I stacked straw bales and put a roof on top of the  bales stabilized by 
diagonal braces but supported by the bails of straw. I then  had my crew mix up 
cob with a rototiller and pile it against the straw bales 8  inches to a foot 
thick. We then removed the diagonal braces. I built the  structure for a 
children's playground and they would not let me use any glass.  The structure has 
a living roof and it is pretty quiet in there, but I do not  know how it would 
be if the ground started vibrating from a train. Note too if  you can a thick 
piece of glass spaced from a thin piece of glass will damp sound  because 
they have different vibration frequencies.
 
Ed