I plan to build a couple of concrete block walls with stone veneer. Everything I'm reading in regards to a seating wall basically says to dig a trench about 6" deep for the base. I'm in Colorado and thinking that this will not hold up for long due to freeze thaw issues. Won't the veneer eventually crack? I plan on a concrete foundation for the wall approx 16" deep (the height of the seating wall). Would a 6" base under this be sufficient or does the foundation need to be below the frost line? 32" in my area but I'll probably dig another 6" just to be on the safe side. (Boy that would be a lot of concrete! $$$$) If I do need to go below the frost line could I make the base and sub base fill most of this depth instead of concrete? So say a base and sub base of 22" and then build the 16" foundation? Thanks.