When people come over to my "house" for the first time, there's usually some confusion: Why are there two front doors? Is this an apartment and who's in the unit next door? It's that it wasn't always a house but originally more of an early 1900's mixed-use building with retail (bar then corner grocery) on bottom and small-ass apartments on top, hence the two entrances. At some point (assuming when it became a grocery) a 4" concrete slab was poured over the original oak floors. At some other point the sheer weight and age led to some sinking. This was all reinforced but the floors became hella unlevel.
When I bought it it had been a domicile for about a decade and the concrete flooring was carpeted over with a raised platform over the most un-level area. I gutted, reconfigured the layout and rebuilt. Everything turned out great except the floors. I went through bag after bag of self-leveling stuff before laying a 3/4", click-and-lock, floating bamboo floor, which now drives me up a wall. They bounce a ton (a year later), scratch easy, always look dirty (cuz they're dark), and are starting to separate in several places. I think they will significantly impact resell value and just ruin an otherwise good remodel.
Now, I'm considering my replacement options. There are two big ones being considered and probably a million I'm not. Both options involve ripping up the bamboo.
Big option 1: somehow cut out all the concrete without affecting the existing walls, counters, built-ins, etc. Build a new frame on top of the existing hardwood, which I can assume is trash now, but shim and rip where necessary to make perfectly level. Lay sub floor, then go with a hard wood that is either glued or nailed down. Concrete would need to exist under the cabinets, island, built-in and a handful of interior walls.
Negatives: sheer ton of work, amount of dust that will go everywhere, complexity of cutting or chipping out around existing structures, and the mystery of what's under there. Positives: if done right, it would be a truly new floor that should last for decades, it would eliminate my biggest barrier to running new electrical or plumbing lines for a couple future projects I have in mind.
Big option 2: skim coat the concrete floor with those new, fancy overlay products. Positives: much less work, would eliminate all bouncing and give a nice, strong, industrial look. Negatives: probably wouldn't make it truly level. would be cold on the feet and less appealing to those not into the complete industrial look. would add yet more weight to the structure.
I plan to trick some architects into taking a look and giving some advice but I wonder if any DIYers or pros out there want to weigh in. Oh, and we're talking somewhere between 800 & 900 sq ft.
Thanks!