Cob: Alternative insulation

[Sojourner]

Here's an idea from "The Owner-Built Pole Frame House" by Ken and
Barbara Kern.

Take a piece of 5" stove pipe.
Wrap it in Kraft paper.
Seal the tube with tabs of masting tape, crimp one end.
Fill the pipe with sawdust.
Remove the pipe.
Crimp and seal the open end.
Lay up on its side in the wall cavity.
Lay "insulation tubes" end to end and stacked between girts.
He doesn't say this, but I would stagger the ends of these like you
would if you were laying up bricks.

He further suggest mixing the sawdust or wood shavings with 10% (by
weight) ammonium sulfate or borax to increase fire retardance, although
packed sawdust is already not particularly flammable.

I can get all the sawdust I want around here for free.  I'm going to
give this a try.

Only problem is I'm not sure how to evenly mix in the fire retardant.

Holly ;-D