Concrete foundation crack? What's the appropriate way to fix?

Hi All,

We had some insulation problems around one of the baseboards downstairs. Warm air would coming in from under the baseboard along one of our exterior wall in the summer. Our townhome is on a concrete slab in North Carolina. We had to take off the baseboard and open up the drywall to inspect. Turns out there is a long crack in the foundation (after opening up the drywall we can see this line goes all the way along the entire exterior wall). The crack seems to be between the concrete foundation and the wood beam/brick wall surrounding the foundation (not sure what's the correct term for this thing). And we had several contractors came and they agreed its a construction defect. One of them said the builder built the frame on the brick wall instead of the concrete foundation! (If looking from the outside there are some brick walls along the foundation and on top of them are the vinyl sidings.) And now the wall is moving away from the foundation and the crack appeared. But we are not sure if thats really the case. All we can see by opening up the drywall is this crack along the beam. Any one knows how to repair this?? I've attached a pic.

Thanks!!!

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I'm not sure I completely agree with the contractor's assessment. The wood is on the actual foundation and the brick is, most likely, just a veneer facing applied-to or tied-to the foundation's concrete. What you have is improper and looks to be a slab that was poured or laid after the wood started going up...a floating slab.

- This isn't top quality nor proper and may not even be legal for anything but a detached garage or basement. Although, to "fix-it" I'm not sure is worth it. I'd have the place checked for dangerous Radon Levels and Gauge the crack changes over a year before doing anything about it.

- If Radon doesn't turn out to be any concern and the crack just grows and shrinks with temperature changes, then you can just Spray Foam and Caulk the crack shut to keep out bugs, air, water and humidity.

- A low-level fix would entail drilling through the brick and screwing the foundation back to the slab in hundreds of places. But really, the proper fix would be to remove the entire slab, jack-up the house and re-pour it over the foundation to then re-install the walls. Do this one wall at a time and you lose the sinkhole and ground subsidence warning and protection.