[Cob] Marlin's rubble trench

[Mary Lou McFarland]

Marlin you mentioned in your post that you like the washed gravel over the 
crushed limestone.  Just wondering why you had that preference.  Hadn't 
thought about it before but had assumed that I would use the crushed stuff 
because of it's greater stability  when taking on weight or impact like 
floor or arena base or shoulders on secondary highways.  For clarification, 
when you say crushed limestone, I am assuming that you mean what we call 
base gravel around here and it has all the fines in it and that is what 
gives it it's strength.  Also wondered what size you usually go with.