Cheap lifts?
So I cut the slab and poured thicker footers. I ended up with 16" thick and went 8" under the existing slab around the edges -- overkill, but I feel nice and confident when I'm under a car. I also hired a company to install it, which I highly recommend. Bolting together the assembly is easy enough, but the setup required adjustments that I would much rather leave to a professional.
It's not the end of the world if you end up needing a thicker slab. My 12k required 6" minimum, and I had 4" (story of my life... :))
So I cut the slab and poured thicker footers. I ended up with 16" thick and went 8" under the existing slab around the edges -- overkill, but I feel nice and confident when I'm under a car. I also hired a company to install it, which I highly recommend. Bolting together the assembly is easy enough, but the setup required adjustments that I would much rather leave to a professional.