I know we got some contractors/engineers out there. My slab garage slab failed. I knew it was a problem when I bought the house and priced that in accordingly; I'm just getting around to dealing with it. I am pretty sure it failed because: (1) un compacted fill and no compacted rock under the slab; and (2) drainage issue allowed water to run between a hole in the dirt where the driveway meets the slab, around the footing and under the slab. There was about a 8-10 inch void under about half the slab where the dirt settled before I took the sledge to it. I don't have issues with the footing; the house is level; and there is no cracking or sticky doors anywhere in my house; I have a basement and there are no issues with the basement. I'm also independently fixing the drainage issues, which is a whole separate project.
The slab appears to be just floating separate from the footer. Can I just use the current footer as a form, fill the floor with compacted crushed rock and a vapor barrier and pour, or do I need some sort of form between the footer or the concrete driveway and the slab so that the slab floats only on the dirt? I was thinking it might need some sort of rubber between the slab and the footer to let it float and deal with shrinkage or expansion if any occurs.
I also want to do it right. Is rebar overkill? I've been reading you just want good concrete with fiber and maybe metal mesh and a good base. My biggest concern with rebar is, fuck me, getting it out if I ever need to again. Hammering out no-rebar concrete is a fucking pain in the ass, I can't image how bad it would be with re-bar running through the middle of it.
I plan on doing as much work as I can myself and only hire when I need to. I will likely hire help for the flat/finishing work when I am at that point but I'd like to get the prep work mostly done myself.