Looking for an opinion. I'm planning a remodel, which includes converting an existing attached garage into a kitchen and dining room. (We will be building a detached garage, so I'm not concerned about losing the space).

We obviously need to level the floor, which slopes a standard 4 inches for drainage. We will be putting an island in the kitchen, so there will have to be some chopping done to run the water, vent, and waste lines. Also, we're removing two columns and replacing the header with with a 20 foot steel beam, which will need a footing for the new column.

I've spoken with a number of contractors during the bidding process, and I've received a mix of opinions:

Half recommend chopping the slab and patching, as needed for the plumbing and columns. Then, they will level the garage floor with mud and tile.

The other half recommend removing the slab completely and pouring a new one. The added benefit of this is that we will gain 4 inches of ceiling height (~8'4" instead of 8').

The incremental cost of the new slab is about $4,000.

I'm leaning towards the latter, but I am not 100% sold. Is leveling the floor with mud a solid approach? I'm wondering if it'll create a headache if we retile the floor in 10 or 20 years and aren't planning to remove the cabinets?