(I originally posted this under the "Foundation" board, but I think it belongs here....)

I would like to make my slab-on-grade floor level. I'm considering having hardwood floors installed, but even if I go with carpeting, I want the floor flat and level. I recently had a 1/4" wide crack which runs from an outer wall across my living room/dining room (caused by settlement of my 10-yr old townhouse) repaired by a concrete contractor hired by the condo association. The slab is uneven with non-uniform vertical displacement of the slab on either side of the crack, with the highest hump in the middle of the room (~1/8"). Near the walls, the slab is even on both sides of the crack.

The contractor filled the crack and laid a concrete patch over it, but didn't level the patch with the slab. The patch is actually somewhat mounded, so now the higher points in the slab are even somewhat higher, more like 1/2" instead of the original 1/8".

What is the best way to level this slab floor? Grind the high points of slab down to match the rest of the slab? Cut the worst sections out and repour? Somehow chip or cut away the higher parts and pour a thin concrete layer to smooth it out to match the rest of the slab? Or could a self-leveling mixture be used to bring the whole floor up to the level of the high point? Other??

I'm not planning to do the work myself. Would a concrete contractor need to do this? Would a flooring installer do this sort of work?

Good Morning, NJ,
The easiest part of your answer is yes, your flooring installer should be able to accomplish the slab leveling before installing your floor.

He/she will most likely use a combination of exactly the techniques you mention--grinding off the high spots, and using some amount of latex float (leveler) to create a level surface for your hardwood. For your peace of mind, and to know you have a qualified installer, watch him on the first day of install, aside from the obvious grinding, then adding leveler, he will run a bubble level, probably a 4' one in all directions, and over all of the floor, checking for high and low spots, correcting them when found.
To qualify my answer for you, we are a high-end custom design/build firm out of the Dallas area, and just did this--having our floor subcon company install very spendy wide-plank handscraped floor in a slab home remodel--the prep time to be sure the floor was ready, was nearly as long as the 600 sq ' of flooring laid.

Thanks much for the info, Texas Builder!
Sounds like a messy and costly job if it takes as much time to prep as it does to lay the floor. I might not be able to afford hardwood after all. But at least the floor will be even for whatever I lay down.
I'll have to get talking to some floor installers.