Mudjacking is a traditional concrete-raising method that lifts a sunken slab by pumping a heavy, water-based slurry of soil or clay, sand, limestone, and a small amount of cement into the void beneath it.
In depth
Mudjacking has been used for decades and does raise concrete, but it carries real disadvantages. The slurry weighs more than 100 pounds per cubic foot, adding significant weight to soil that is already failing, which can encourage the slab to settle again. It requires large injection holes, typically 1-5/8 to 2 inches, and many of them because the thick mixture does not flow easily, and it needs 1 to 2 days to cure before the surface can bear weight.
The slurry is also aggregate-based, so its composition varies from contractor to contractor and it remains vulnerable to erosion and washout over time. These limitations are why polyurethane foam was developed as a lighter, more consistent, longer-lasting alternative.
How Acme applies it. Many highway, tollway, and municipal projects in Illinois no longer permit mudjacking at all, specifying polyurethane for its consistency and load performance, the standard Acme works to.
Related terms: Polyurethane Concrete Raising, Polyjacking, Slabjacking, Soil Washout
Frequently asked questions
Why does mudjacking not last as long as polyurethane?
The slurry is heavy enough to overload weak soil and cause renewed settling, and because it is aggregate-based it can erode and wash out when exposed to water and moisture over time.
How big are mudjacking holes compared with polyurethane?
Mudjacking typically needs holes 1-5/8 to 2 inches across, while polyurethane injection uses holes about 5/8 inch, the size of a dime, that patch more cleanly.