I have an old building that I am converting into a living space. The slab foundation is very old and uneven in a lot of spots. I need to level it, but I can't increase the height of the floors too much, or I won't have enough head room for the building code.
I would like the entire floor to be level, so I can finish it with tile, carpet, or laminate. My original thought was to lay sheets of plywood down and level them with shims. I would only lose about an inch of height. The obvious way would be to use leveling cement, but that is too expensive. At 800sqf it would be around $4,500.
Is there an industry standard or would laying plywood down be my best option?