im looking to start a shop with cnc machining. i will defiantly have my slab engineered and designed before i build but for budgeting purpose and understand what im looking at how thick would my slab need to be. im planning a 100ftx100ft slab with rebar and helix enforcement. im wanting to put several 28,000lb 114in x 189in machines in a main section of my shop and pour a thicker section for 382in x 215in 73,000lb machines