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?

There are contractors who have the ability to level concrete slabs such as yours by forcing a special concrete mix under the lower section(s) under pressure. The process is known by several names, including mudjacking, slabjacking, concrete lifting, and concrete leveling. This process is usually much less expensive than replacement. Try your yellow pages or a web search to find a local contractor.

Are you reasonably sure no more differential settling is occurring? From your description, it appears that the slab has settled on either side of the slab which caused the crack in the first place. When the repairs you mentioned were made, did they also take steps to stabilize the exterior walls that have settled?

HSIGene

Thanks for the advice folks...

but after all this, I'm thinking I better forego hardwood installation. Seems too risky with the uncertainty of the settling situation. I don't trust that the engineering firm hired by the home owner's association (which is responsible for repair/replacement of structural elements in my townhouse) did a particularly thorough evaluation of the problem. Maybe I'm just overly cynical. But they didn't check the foundation footers(?) or do any soil sampling. They evaluated the evidence in the house itself: no cracked walls, no separation between wall and ceiling, no windows or doors out-of-alignment, etc..

I'll maybe have the lovely cosmetic hump that was left by the contractor ground down and have the slab evened out some, and then I'll just lay new carpet in this area and take the money I saved by not installing hardwood and buy a big screen TV instead. ;-)