New client that had a large stump in the front yard. Someone at some point and time has attempted to grind it. It now sits well below the surface. My question is how much topsoil do I need to be able to put on it before I can Kay sod over it? I'm thinking I can probably get a good three inches plus sod and still have it be fairly even with the other grass. She is refusing to grind it anymore so that is not an option. Thought tips ideas ?