How the ground is prepared plays a huge role in the longevity of a building.  It is often thought, “just throw some dirt down and get it level”, but there is much more that needs to be done to increase the stability of your building.  All vegetation including grass and tree roots must be removed so they don’t decay and allow the building to settle.  Granular, non-organic fill must be used to allow water to easily flow away from the slab and is highly compactable.  Properly compacting the fill is key to ensuring further settling does not occur after the building is constructed.  Movement due to frost will occur under a normal slab for a detached accessory building but taking the proper steps during preparation will minimize this problem too.