I actually had to build the floor up around 18-24 inches (under the concrete) because the shop was in a low spot. It was built up a few inches at time with "AB" (a term used out west to grade the material). It's what is commonly used to "bed" concrete in this area, it compacts very well. Every few inches I compacted the AB with a gas powered compactor.
I'm pretty confidant that the bedding was done very well if not over done. |