24 Feb Mudjacking vs. Concrete Lifting: How are They Different?

Mudjacking vs. Concrete Lifting

Concrete lifting refers to the process of injecting a material under a concrete slab that has sunk or settled in order to raise it. For this reason, concrete lifting is also called concrete leveling, and the terms are used interchangeably. The goal is to bring the sunken or settled slab back or as close to its original position without demolition or replacement.

This injected material can be composed of different mcixtures. This slurry fills the space between the concrete slab and the soil until the desired height is reached. Once the injected material dries, it becomes a strong and solid base.

Polyurethane foam or foam concrete can provide this stable base, so does stone slurry grout. Another method of concrete lifting involves a concrete slurry that’s sometimes called “mud.” This method is known as mudjacking.

What is mudjacking?

As a method of lifting or leveling concrete slabs that have settled or sunk, mudjacking also involves a type of injected material. This is the concrete slurry or mud, which varies depending on the contractor and equipment. Typically, it consists of a mixture of cement,  soil or sand, and water. Some contractors might add limestone too.

The slurry should be just the right consistency that it can both move through the hose and injection gun as well as dry out or cure quickly. As the mixture is pumped through the hose under the slab, the pressure causes it to rise. Contractors will add just the right amount of this slurry to level the concrete slabs. Some people say the action of the slurry pushing up the concrete slab is similar to jacking up a car and hence the name.

Mudjacking is an old concrete lifting method which has been around for more than 70 years. It is widely used to repair sunken or settled concrete slabs as it is affordable and quick, with the entire process completed in as little as a matter of hours.

How Does Concrete Lifting Work?

Regardless of the type, concrete lifting follows the same basic steps. These are:

Step 1: Drill holes in the concrete.

These holes can be as small as ⅝ inches to as large as 2.5 inches, depending on the type of filler or method used. Contractors drill these holes in strategic locations of the sunken or settled concrete slab.

Step 2: Inject the filler mixture.

Using a hose and hose gun, specialized equipment pumps the chosen mixture under the concrete slab. The stone, foam or mud slurry will fill the voids underneath and raise the slab. Contractors add as much slurry as necessary to lift the affected slab to the same level as the others.

Step 3: Patch or seal off the holes.

Once the slabs are leveled, the holes are sealed.

Mudjacking vs. Other Types of Concrete Lifting

Mudjacking is sometimes used as an umbrella term for concrete leveling, but it is actually a type or method of concrete lifting. All types of concrete lifting follow a similar process but mudjacking differs from them in the following ways.

Lifting compound

As mentioned, mudjacking uses a mixture of cement, sand or soil, and water. Contractors who want a stronger mud or slurry use Portland cement.

Stone slurry grout concrete lifting, on the other hand, uses just two ingredients: water and crushed agricultural limestone. This mixture is strong and dense and can be made even more stronger with Portland cement.

Meanwhile, polyurethane foam concrete lifting only uses a two-part polyurethane foam. Once injected under the concrete slab, the foam expands and lifts the slab back in place.

Drill hole size

Polyurethane foam concrete lifting or polyjacking uses the smallest drill hole size of the three methods: just ⅝ inches in diameter. Drill holes for stone slurry grout concrete lifting are a little bigger at 1 inch in diameter, which is about the size of a quarter. Mudjacking requires the biggest hole size because of the higher pumping pressure it uses. The holes can be 1.5 to 2.5 inches in diameter.

Applications of Mudjacking

Mudjacking is best for sagging parking lots, uneven patios, cracked sidewalks, and other sunken or settled concrete slabs located outdoors. Basically, concrete slabs that present a tripping hazard can be leveled through mudjacking.

It is a quick fix to these problems. Contractors can be done with the job within a half or full day and it only takes 24 hours up to  three days (for larger jobs) for the mud slurry to dry out or harden. Plus, it does not entail demolition or replacement. When done right and maintained properly, mudjacking can last from 5 to 20 years.

Furthermore, mudjacking is an affordable option to fixing uneven and settled concrete. It is less expensive than replacing the slabs. Some estimates say it is about 10% cheaper than the other types of concrete lifting, depending on location and other factors.

Limitations of Mudjacking

Despite the benefits or advantages of mudjacking, it does have some limitations. First of all, it’s a temporary fix and will not address any structural issues. For instance, mudjacking can’t be used to raise foundations or intact concrete slabs. It also can’t be used to repair pools and potholes. In addition, mudjacking will not be able to repair severely damaged concrete slabs; these have to be removed and replaced with new ones.

When it’s done, drill holes will be visible and existing cracks or other blemishes will also still remain. And, after some time, mudjacking will start to decay, erode or break apart. There’s also a possibility of the concrete slab sinking or settling again either because of the soil, water, or the added weight to the concrete.