I am looking to convert an old garage into a workspace. The total concrete area is about 20ftx22ft, and has one seam down the center. The pad on the north side of the seam is level. The pad on the south side has a grade from settling after 60+ years. It averages a downward grade at about 1.25 inches over 9 ft. I am going to be putting LVP down eventually, so I need it moderately level, and have been trying to think of a cost effective way to fix the slab.
The first option I thought of was self leveling concrete, but the amount of material that I would need would come out to $1,600+. Which is a lot of money that I don't really want to spend.
The second option I thought of was to put down OSB on one side, and then build tapered joists for the grade side, but I probably would want to put some type of dimpled plastic membrane down? I am not too concerned about water leakage, but it is probably something that most people would recommend.
Another option is to use Dri-Core, but can I shim that much of a grade to level?
Are there other options I could do? What is the best way to level such a large area with that deep of a grade?