This past winter, my concrete driveway heaved 1.5" above where it meets the garage floor. It is three years old. Also, we dug along the sides of the drive to try to guage if a 4" slab was actually poured- discovered many crevices on the side. Could this cause a problem later? Specifically cracking?
Concrete drive heaves where it meets garage floor
concretedriveway
Related Solutions
You can install an interior weeping system similar to what you would normally do on the outside, but without the waterproofing.
Start by jackhammering out about two feet of floor around the edges of your garage, as close to the walls as you can get. Dig down until you reach dirt, and if that's not at least two feet down, keep going. Now, put down a couple inches of 3/4" crushed gravel, and then install weeping tile (it's not tile anymore; it's 4-6" corrugated plastic drain pipe with a nylon mesh sock over it). Make sure the sock is continuous across any joins you make in the weeping tile for corners etc. This is a good time to direct those drain holes down into this trench, where the water they drain will flow into the weeping tile. You'll also need a sump, or a connection to a downhill storm sewer; direct the weeping tile to this sump pit or the storm drain. While you're doing all this a center drain can't hurt too much; you can tie it into the weeper wherever it's convenient, just make sure the garage floor and the drain flange are level, or that the garage floor slopes slightly to the drain.
Now, you can install waterproof sheathing on the interior walls contacting the concrete. Normally this product is designed to go outside the foundation walls, but in cases where that's infeasible it can work this way too. The idea is to trap moisture that weeps through the wall behind the sheathing, where it will then be directed down the wall and under the slab to the weeper. So, you'll install the sheathing, which should have an air space between wall and most of the layer, and make sure the end is down in the trench by the weeper.
Backfill the rest of the trench with 3/4" crushed gravel up to the slab footing, then patch the slab with new concrete. Your garage should stay much drier.
What you want is something like this:
Get some Red-Heads or other appropriate concrete bolt and fasten it down. Slip the 4x4 in and tighten it up.
Ideally, you should still have some posts properly embedded in the ground to help support the torque caused by someone leaning on the fence, but you can use these in between.
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Best Answer
Frost heaves are caused by water in the ground freezing and pushing up. The thickness of the slab has nothing to do with it. The force caused by ice expanding when it freezes is huge, and it's almost certainly not practical to resist it. Better to remove the force in the first place.
There are only two ways to prevent frost heaving, and neither is perfect:
Dig down below the frost line. This is obviously not practical for a driveway. (Also, even a foundation whose bottom is below the frost line may be susceptible to heaving if water can freeze around the sizes and pull it up.)
Reduce the amount of water underneath the structure with grading, drains, etc. A properly-prepared subsurface can also help here by reducing the water content of the soil
What is the drainage situation like around your driveway?