I am planning on laying a granite patio 10' X 30' with a roof over it. I have a pile of granite pieces 4'X7'X2 1/2' high, scraps from a local granite shop. The pieces are irregular shapes with very few straight edges and 3/4" thick. I have been in the building trade for 30 years but have never done a patio with anything but concrete. Any advice on base for laying the granite and grout verses sand filler?