A frequent question we hear is ‘what is the difference between mud-jacking and foam concrete lifting?’ Here are a few points to help you make an educated decision on what is best for you and your concrete lifting needs.

Mud-jacking and Polyurethane foam injection are both methods commonly used to lift and level concrete slabs that have settled or become uneven. There are several differences between the two methods.


The most obvious difference between the two methods is the material used. Mud-jacking uses a slurry mixture of water, soil, and cement. Polyurethane foam is a two-part liquid material that when combined, a chemical reaction takes place causing foam to expand. Part A and Part B of the polyurethane foam are mixed at a precise time during the injection process allowing it to flow smoothly into voids and expanding deep within to fill all spaces.

Injection Process

Mud-jacking involves the drilling of larger holes in the concrete through which the slurry mixture is pumped underneath the concrete slab. Polyurethane foam is injected below the concrete through smaller holes, called ports, where the liquid material expands, filling the voids beneath the concrete. The mud-jacking holes are approximately 2”, which is roughly the size of a billiard ball. Whereas the holes for foam lifting are 5/8”, approximately the size of a marble.

Curing Time

Mud-jacking can take several hours or even days to cure completely. Polyurethane foam cures within minutes. Clients who use foam concrete lifting can park on their driveway immediately after the job is completed.


Polyurethane foam is considerably lighter in weight than the mud slurry used in mud-jacking. This is an important consideration as it exerts less pressure on the underlying soil and surrounding structures.


Polyurethane foam creates a more precise and controlled lift than mud-jacking. As the foam is injected, it uniformly expands to fill voids and crevasses. The rate of injection can vary to achieve the desired amount of lift. Since mud-jacking is not an exact science, it has the potential to create uneven lifts and may not provide as precise of a result.


Polyurethane foam is more durable and longer-lasting than mud-jacking. Foam does not settle or shrink whereas mud-jacking can be washed away over time.


The 6 main differences between mud-jacking and foam concrete lifting:

  1. Material Used
  2. Injection Process
  3. Curing Time
  4. Density
  5. Result
  6. Durability

Overall, Polyurethane foam offers a precise, efficient and long-lasting solution for lifting and leveling concrete slabs.

Learn more about our concrete lifting services, and learn more about the process and environmental benefits of TCB Foam Solutions >