You pull in and the car drops right as the tires hit the apron at the garage. The slab might look fine out in the middle, but at the door there’s a dip that holds water, a gap you can catch a toe on, or a crack that keeps widening. Sometimes the garage floor stays put while the driveway settles. Sometimes the whole apron goes down and the first control joint opens up.
In Albuquerque, NM we see this a lot after a wet monsoon season, or after a winter where freeze and thaw works on a spot that already has water under it. The problem usually is not the concrete itself. It’s what’s under it, and what water is doing around it. The fix depends on how far it’s sunk, how sound the slab is, and whether we can stop the water that caused it.
Settlement at the garage is usually base, soil, and water working together
That garage approach is a transition zone. You have roof runoff, yard runoff, and often a downspout that dumps near the corner. You also have vehicle loads concentrating as you brake and turn, right where the slab meets the garage floor.
Under a driveway we want a compacted base, typically a crushed aggregate base that locks together, not loose native dirt. If that base was placed too thick in one lift, or not compacted with a plate compactor or roller, it can settle later. Settlement shows up first at the garage because the slab edge is restrained by the garage floor and the stem wall. The driveway slab can drop while the garage slab stays.
Expansive soils add another layer. Clay can swell when it’s wet and shrink as it dries. That movement makes voids, and then the next storm pushes water into those voids. You end up with a slab that is spanning, not bearing.
What expansive soils do under a driveway slab in our high desert climate
Expansive clay is a volume problem. It can change shape with moisture, and it does it unevenly. The soil near the garage stays wetter because of shade and runoff patterns, while the middle of the driveway bakes dry in the sun. That moisture gradient is what makes one end move and the other end stay.
You’ll see a few common failure modes:
- A crack that starts at the garage corner and runs diagonally toward the first joint.
- A settled apron with a “birdbath” that holds water for hours after rain.
- A gap at the slab edge where you can see daylight under a corner.
We manage expansive soil by controlling what the slab bears on and how water is handled. On replacements, that means removing soft subgrade, installing a well graded base, and compacting in thin lifts. It can also mean a thicker edge and proper reinforcement at the approach so the slab acts as one piece. The point is to build a platform that does not change every time the moisture changes.
Monsoon runoff and roof drainage are the quiet drivers of sink-at-the-garage
If water is getting under the apron, the slab will move. It does not take a river. A downspout that dumps next to the garage corner through July and August can wash fines out of the base. That is how voids get created.
We look for clues. Splash marks on stucco near the corner. Erosion channels in the gravel. A downspout elbow pointed at the driveway. A flat spot where water sits against the garage stem wall.
The fix is not just concrete. It is drainage detail.
- Extend downspouts away from the slab, or pipe them to a safe discharge point.
- Maintain positive slope away from the garage. A practical target is 2 percent, which is about 1/4 inch per foot.
- Seal joints that are taking water. A joint that is open at the garage is a direct path for runoff.
In Albuquerque, NM monsoon storms hit hard and fast. If the driveway is the low spot, it becomes the collection pan. You can repair the slab and still lose the battle if the water path stays the same.
How we confirm the cause before we recommend a concrete driveway repair
We do not guess from a photo. We check elevation, cracking, and movement. A 4 foot level and a tape measure tell a lot. We measure the drop at the garage, the slope of the first 8 to 12 feet, and whether the garage floor is acting as a reference that has not moved.
Then we look at the slab condition. If the concrete is sound and the drop is localized, we can often save it. If the slab is broken into multiple pieces, rocking at corners, or has wide cracks that are offset vertically, it is usually past a simple lift.
A few specifics we pay attention to:
- Vertical displacement across a crack. If one side is higher, the slab is not just settling evenly.
- Joint condition at the garage. If the joint is washed out, water is getting under it.
- Edge thickness and reinforcement clues. A thin edge at the apron is more likely to break during lifting.
We also check irrigation. A drip line that runs along the garage wall can keep the soil wet all season. That is enough to keep the cycle going.
Slabjacking and foam lifting, where they work and where they don’t
If the slab is intact and has settled a manageable amount, lifting can be a good concrete driveway repair. The goal is to fill voids and bring the slab back to grade so water runs off instead of under.
There are two common approaches: cementitious grout pumping (slabjacking) and polyurethane foam lifting. Both involve drilling small holes through the slab, injecting material to fill voids, and carefully raising the concrete. The holes are then patched.
Where lifting works best:
- A settled garage apron with minimal cracking.
- A slab that dropped as one piece at the first joint.
- A situation where we can also address drainage so the problem does not repeat.
Where lifting is a bad bet:
- Multiple broken panels with loose corners.
- Severe base loss that extends far under the driveway.
- A slab with thin, crumbling edges that will spall under pressure.
Lifting is not a magic reset. If water keeps running to the same spot, it can settle again. We treat lifting as part of a system repair, not a standalone trick.
Partial replacement at the apron, how we tie new concrete to old so it holds
When the damage is concentrated at the garage approach, we can often remove and replace just that section. The detail that makes or breaks it is the tie-in.
We sawcut a straight line, then remove the failed panel down to subgrade. We rebuild the base, compacted in lifts. On the concrete side, we dowel into the existing slab so the new panel does not drift or settle independently.
A typical dowel detail is #4 rebar (1/2 inch) drilled and epoxied into the existing slab at regular spacing. We use a structural anchoring epoxy rated for concrete, not a general purpose adhesive. We also isolate where we should. At the garage slab, an isolation joint keeps the driveway from pushing on the garage floor during thermal movement.
For the new pour, thickness and reinforcement matter. A driveway panel is commonly 4 inches thick, with thicker edges where vehicles transition and turn. Reinforcement can be rebar or welded wire reinforcement, placed at the correct height so it does its job.
Partial replacement works when the rest of the driveway has stable base and good slope. If the middle is also moving, patching the front just delays the full fix.
Full replacement is the right call when the base and drainage are wrong everywhere
Sometimes the apron is just the first place you notice it. The whole driveway can be riding on inconsistent base, with low spots and cracks telegraphing the same story. If multiple panels have settled, or if the driveway has been patched several times and keeps moving, replacement is usually the cleanest path.
A proper replacement is not just tearing out and pouring back. We correct the things that caused the sink.
- Subgrade prep: remove soft spots and organics, then recompact.
- Base: install a crushed aggregate base and compact it in thin lifts so it is uniform.
- Slope: set grade so water runs away from the garage and off the driveway.
- Joints: put control joints where the slab wants to crack, and keep joints tight and sealed where water can enter.
Timing matters too. Concrete placement and curing in New Mexico has to respect temperature and wind. Hot, dry days can pull moisture out fast, which is why curing methods like wet curing or curing compound are not optional if you want a durable surface.
If you want the driveway to stop moving, we have to give it a stable platform and a place for water to go.
Key Takeaways
- Settlement at the garage usually starts with water getting under the apron and weakening the base, not with “bad concrete.”
- A 2 percent slope (about 1/4 inch per foot) away from the garage helps keep runoff from feeding voids.
- Diagonal cracks from the garage corner and “birdbaths” at the apron are common signs of base loss and moisture cycling.
- Slabjacking or foam lifting can work if the slab is intact and the drop is localized, but it will fail if drainage is not corrected.
- Partial apron replacement holds best when the new panel is doweled into the existing slab and the base is rebuilt and compacted in lifts.
- Full replacement makes sense when multiple panels are moving, the base is inconsistent, or water management is wrong across the whole driveway.
Conclusion
If your driveway is sinking at the garage, the first step is figuring out where the void came from and why it keeps getting fed. That’s usually a drainage path, a base that was never compacted right, or expansive soil that’s being kept wet on one end and baked dry on the other. Handle it the same way every time: measure the drop, look at runoff, and decide if the slab can be lifted, if the apron should be replaced, or if the whole driveway needs a reset from the ground up. If you’re in Albuquerque, NM and that dip is holding water at the garage door, it’s worth addressing before it starts pushing water into the joint and breaking the first panel.