We have our own barn and pasture and we are in the process of putting dirt under the barn to prepare the stalls. We bought a pre-made shed row barn from the Amish and so we created a foundation for it and in order to make it level, it is raised 19" on one side. Because of that, we have to put dirt under it. We are filling it with "bank run" which is a high-packing dirt. We plan on putting mats in the stalls, so we were told to put bluestone dust on top of the dirt and then put the mats on top of that. My mom read that we need to have 4-6" of bluestone dust under the mats for proper drainage.
My question is this: Is 4-6" really necessary, or can we use more along the lines of 2-4"? It just seems like an awful lot of bluestone, and we are getting strapped for money as it is since the project ended up costing a lot more than originally planned. Any advice, suggestions? If you have your own barn, how did you plan for the mats, if you use them? Thanks in advance!