Concrete does not really sink. The ground under it gives out, and gravity does the rest.
Olathe sits on silt loam topsoil over a heavy clay subsoil. That clay swells when we get a wet spring and shrinks back when we get a hot, dry August. Every time it moves, the support under your flatwork gets a little worse, and eventually there is a void under the slab with nothing holding it up.
A few things make it happen faster, and we see all of them here:
If water is what is undermining your slab, lifting it is only half the job. That is why we also handle drainage solutions and gutter installation, so the same washout does not start over next spring.
Poly jack is short for polyurethane injection, and it is less dramatic than people expect.
We drill a few nickel-sized ports through the concrete and inject a two-part high-density foam. It expands underneath, fills the void, tightens the loose soil, then lifts the slab. We raise it in small increments until it is back to grade, then patch the holes.
The foam sets in about 15 minutes. Most jobs are done in a few hours, and you can park there the same day. No heavy equipment on the lawn, no demo pile, no week of curing.
It is also waterproof, so it will not wash out, and it weighs only 2 to 4 pounds per cubic foot. That matters in Olathe clay. You are not stacking more weight on soil that already failed once. More on how the process works is on our main Kansas City polyjacking and concrete leveling page.
We price poly lifting by the material, at $10 per pound of foam. So your concrete raising cost comes down to how much foam it takes to fill the void and lift the slab. Square footage, how far it dropped, slab thickness (a 10-inch garage floor eats far more foam than a 4-inch sidewalk), and how close we can get the rig.
You can find cheaper quotes in Olathe. The difference is usually how much foam goes into the ground and what grade it is. Skimp on either and the slab drops again, which is how people end up paying twice.
Compare that to the alternative. Tearing out and replacing a driveway runs $18 to $22 per square foot, and a patio $20 to $24. Then you wait days for it to cure, and the new slab goes right back onto the clay that failed the first time.
Full rates are on our pricing page.
Mudjacking pumps a heavy sand and cement slurry under the slab. It works, and it is usually a little cheaper up front. But in Johnson County it has two problems: the slurry is heavy, roughly 100 pounds per cubic foot, so it loads more weight onto soil that is already failing, and it is not waterproof, so heavy rain can erode it out again.
Here is the short version:
| Poly jack (polyurethane) | Mudjacking | Replacement | |
| Ready to use | Same day, about 15 minutes to cure | 24 to 72 hours | Several days |
| Weight added to soil | 2 to 4 lbs per cubic foot | About 100 lbs per cubic foot | Full new slab |
| Water resistance | Waterproof, will not erode | Can wash out | Base can wash out again |
| Holes drilled | About 5/8 inch | 2 to 2.5 inches | Not applicable |
| Cost | Moderate | Lowest up front | Highest by far |
If your concrete is structurally sound and just out of level, lifting it is the smart move. If it is crumbled, spalled, or broken into gravel, no foam will save it, and we will tell you that. In that case, our concrete contractor crew can talk to you about a replacement pour.
If it is a free-floating slab, we can almost always lift it:
That last one is worth calling out. If we find a void but the concrete has not settled much, filling it now is the cheapest visit you will ever have from us.
Call (913) 592-3300 or send us the address and a photo of the slab. We will get you on the schedule for a free look, usually within a few days.
On job day, we drill nickel-sized ports through the settled sections and inject the polyurethane. We raise the slab in controlled increments, checking the surface as it comes back to grade so it lands level with everything around it. Then we patch the ports and clean up. Most Olathe jobs are one visit, often half a day.
The foam cures in about 15 minutes. Walk on it, park on it, roll the trash cart over it the same afternoon. The trip hazard is gone, the water drains the right way again, and the slab is sitting on something solid.
We price poly lifting at $10 per pound of foam injected, so the number depends on how big the void is and how heavy the slab is. A couple of sidewalk panels are a very different job from a settled garage floor. Estimates are free, so you get a firm number before anything gets drilled.
Polyurethane foam does not dissolve, erode, or wash away, so the fill itself is permanent. What can change is the soil around it, which is why drainage matters so much here. If water keeps eroding the base next to the repair, a new void can form nearby.
For most Olathe properties, yes. Foam is waterproof, weighs a fraction of what mudjacking slurry weighs, cures in minutes instead of days, and needs much smaller holes. Mudjacking can still be cheaper on the right job, and we will tell you if yours is one of them.
Usually. Garage floors are one of the most common lifts we do in Olathe, as long as the concrete itself is not badly broken up. Thicker garage slabs take more foam, so they cost more than a sidewalk of the same size.
Most residential jobs take a few hours. The foam reaches strength in roughly 15 minutes, so you can typically walk on the slab and park on it the same day.
You will see small patched circles, about the size of a nickel, if you look for them. We fill and smooth them, but we will not tell you they vanish completely. They are far less noticeable than the 2-inch holes mudjacking leaves.
Olathe’s building code exempts sidewalks and driveways that are not more than 30 inches above adjacent grade from permit requirements, so a typical residential lift on your own property does not need one. Work in the city right-of-way, like a driveway approach, is a different story. We handle those requirements as part of the job.
In Olathe, property owners are expected to keep driveways and public sidewalks safe and to maintain the adjacent right-of-way. A raised panel that trips a neighbor is a real liability, and it is a lot cheaper to lift the panel than to replace it.
Not if the reason it sank gets addressed. The foam fills the void and stabilizes the soil, but if a downspout is still dumping at the slab edge, the washout continues. We look at that during the estimate and can fix the drainage while we are at it.
No, and be careful with anyone who says otherwise. Poly lifts free-floating slabs like driveways, patios, and garage floors. If your house itself is settling, that is a job for foundation piering, and we will point you there instead.
You do not have to live with the lip at the garage, the puddle on the patio, or the sidewalk panel everybody steps over. Give us the address, and we will come and look, and you will get a straight bid with a real number on it.
Call (913) 592-3300 or request your free estimate online. Olson Foundation Repair has been lifting Kansas City metro concrete since 1986, and we would be glad to handle your polyjacking in Olathe, KS.
Get professional basement waterproofing & foundation repair services at a
fair price with the quality of service you deserve.