Concrete leveling: mudjacking and foam
Fill the hollow under a settled slab and bring it back up, usually in a single visit.
A slab doesn't sink on its own. Something under it has washed away, compacted or shifted, and the concrete has dropped into the gap. Leveling works from the top: the contractor drills through the slab, pumps material into the hollow, and lets the pressure raise the concrete toward its original height.
What can be raised?
- Front walks and public sidewalk panels
- Driveway slabs and garage aprons
- Patios and back stoops
- Front steps that have dropped or leaned
- Some garage and basement floors, depending on what's underneath
What happens on the day?
- Look and measure. The contractor checks how far each slab has moved, whether cracks run all the way through, and where downspouts and sump lines empty.
- Drill. Holes go in a pattern planned around the void and the cracks.
- Inject and lift. Slurry or foam fills the void first, then raises the slab a little at a time so it doesn't crack.
- Patch and seal. Holes are filled, and joints and cracks are sealed so meltwater can't wash the base out again.
How do mudjacking and foam compare?
| Mudjacking | Foam | |
|---|---|---|
| Material | Cement-based slurry | Two-part polyurethane |
| Hole size | Roughly 1 to 2 inches | Roughly 3/8 to 5/8 inch |
| Added weight | Heavy | Light |
| Back in use | Usually the next day | Often within an hour |
| Relative cost | Lower | Higher |
Does sandy ground change anything?
It can. Much of the St. Cloud area sits on sandy soil that drains fast but moves easily when water runs across or under it. If a downspout has been eroding the base under a slab, the void can be bigger than it looks. A contractor should fill the whole void, not just lift the edge, and you should redirect the water.
When is leveling the wrong fix?
If the slab is broken into several pieces, the surface is badly flaked from salt, or it has dropped several inches because of a drainage problem nobody has fixed, replacement may be the better use of your money. A straightforward contractor will tell you so.
What drives the price?
- How many slabs, and how big
- How far they need to come up and how large the void is
- Mudjacking or foam
- Access for the rig, and whether steps are involved
- Sealing and crack repair afterward
Pricing is set by the contractor after an on-site look, once they know how big the void is and what caused it. We don't quote prices, and a number given over the phone before anyone has seen the slab is only a ballpark.
Where we connect you with help
Common questions
How long does a lift last?
Mostly as long as the cause stays fixed. If water is kept away from the slab and joints stay sealed, a lift can last many years.
Can concrete be leveled during a St. Cloud winter?
Foam can sometimes go in at lower temperatures than slurry, but frozen ground limits what's possible. Most contractors schedule leveling between spring thaw and the hard freeze.
Related services
- Sidewalk repair and trip hazards
- Driveway and garage apron repair
- Steps, stoops and patios
- Joint sealing and crack repair
More background: St. Cloud concrete repair guide.
Slab dropped over the winter? Walk turned into a trip hazard?
Call and a local concrete contractor will come look at it and quote the fix.