New garage with concrete issue

[garagewithattachedhouse]

I 'm a new member but been reading this site quite a bit. I hope someone can help with my issue. We recently moved into a new home with a 1000sq ft garage. During the original slab pour in December 07, it rained on the surface. I had someone come out who was going to lay down epoxy in July and he started to shot blast the floor but the surface flaked off and was not consistant. At this point, the builder was brought in and the concrete contractor used a scarifier to remove the entire top of the surface down about 3/4" to exposed aggregate. They then poured a 9k psi no rock concrete mixture over the surface. It looked good but then started cracking. A few taps of something metal and you can hear its hollow in about 50% of the floor. The structural engineering firm now suggests adding vertical rebar posts and horizontal mesh and repouring on top of the bad concrete 2" thick. This would mean I would have qty 2 2" bumps to drive into the garage and also the garage doors would not fit correctly. I don't want to go through the rework and wait another 28 days to find out its no good. Are they any overlay products that can resolve this issue? I really just want a nice epoxied floor! I have also been researching race deck since this might be the easiest solution. Thanks in advance!!

 

[larry4406]

If the house is still under warranty, have them remove the slab. Been there, done that. Have also capped slabs that were poured low (roughed the surface first and applied a bonding agent, then added 4 inches of concrete with mesh) and had to raise the garage header to restore the door height. Managed to catch this before the driveway was installed.

Is your slab a slab on grade, a structural slab with grade beams, or a monolithic pour? Your ability to remove the slab will also depend on how the walls are framed (i.e., off of the slab or on stem walls). In the case of a structural slab with stem walls, you might be able to remove the slab, retain and dowel into the grade beams, and repour.

 

[Jaguar Fan]

Man, that sux. Talk to the structural engineer about removing & repouring the slab... assuming the engineer is OK with it, make the contractor take out the old one & put in a new one.

 

[AlphaGarage]

Of course you can epoxy over it, but clearly that will probably be a waste of resources.

The floor needs to be examined and repaired by someone who knows what they're doing. It sounds like the builder has had two chances to provide you with a serviceable floor and managed to fail both times. I'd be hard pressed to trust a structural engineering firm that came out to fix a specific problem and yet managed to foul up the fix.

Schedule a reputable concrete contractor to evaluate the situation and estimate what a proper course of action would be. Present the info to the original builder and have him fix it. If he balks, which is very possible, it's time to find out what your legal remedies are.

 

[garagewithattachedhouse]

Thanks everyone for the advice. The garage and house are all one slab and there is plumbing in it also for a garage sink. I'm going to look for a different engineering firm and concrete contractor to see what else there might be. I was hoping for some sort of high performance overlay that cures faster than 28 days that I could still epoxy. Thanks again.