My slab spec was 4500psi 6" slab, foam insulated, mesh reinforced, with PEX installed for the heating system.

When I drilled through for the hoist install I found out it was actually about 7 and 1/2".

Had to decide before the slab was poured exactly where hoist posts would potentially go, route the pex around those areas, etc.

It's possible to saw and jackhammer out smaller selected areas and pour thicker reinforced areas for hoist, if existing slab isn't quite thick enough.