Polyjacking vs. Stone Slurry Grout: Choosing the Right Concrete Leveling Method for Your Settled Concrete

See how foam concrete leveling and stone slurry grout concrete leveling stack up against each other.

If you’re struggling with trip hazards and bad-looking settled concrete around your home or business, concrete leveling just might be the solution you need.

The goal of concrete leveling is to preserve your existing concrete rather than replace it entirely, which ends up saving you time, money, and hassle. While this is the goal of all concrete leveling methods, polyjacking, stone slurry grout leveling, and mudjacking each have their own unique benefits that should be considered before deciding on one over the other.

Here at A-1 Concrete Leveling, we’ve been experts in the concrete repair industry for over 30 years, and in this time we’ve gotten to know which methods best serve different purposes along with the advantages and disadvantages of using each.

In many of our 50+ locations, we offer both polyjacking and stone slurry grout leveling services. Providing both of these services allows us to use the concrete leveling method best suited for each situation. 

But how should you choose which one to go with for your repair? In this article, we’ll define and compare polyjacking and stone slurry grout leveling so you have the knowledge you need to make an informed decision about your concrete.

What Is Polyjacking?

Polyjacking is a newer concrete leveling process that involves injecting expanding polyurethane foam beneath the sunken concrete slab through strategically drilled holes. It’s also called “foam leveling” and “foam injection leveling”.

When the foam enters the voids below the slab, it expands and puts enough pressure on the slab to lift it back up to a level position. Then, the foam hardens under the slab, usually within an hour, and keeps it in its new level position.

Polyjacking Strengths and Weaknesses

Polyjacking Strengths

• Accessibility 

Portable leveling units enable technicians to level concrete in inaccessible areas that can’t be reached with stone slurry grout hoses (200-300 feet from the leveling truck).

• Drill Hole Size 

Polyjacking requires the smallest drill holes compared to the other concrete leveling methods, making them less noticeable and ideal for decorative surfaces.

• Faster Injection Speed

The expanding foam material can be injected into the void beneath a sunken slab at a faster rate, which may mean quicker repairs, particularly when dealing with large voids.

• Quick Cure Time

Polyjacking foam typically cures and can be ready for normal use within one hour. Stone slurry grout leveling repairs can be walked on immediately but are not recommended for normal use for 24 hours.

Polyjacking Weaknesses

• Higher Cost

The materials used in polyjacking are more expensive, resulting in higher repair costs overall.

• Less Control 

The foam expansion during a polyjacking repair offers less control over the exact extent and direction of the lift, which may result in over-lifting or other unexpected outcomes.

• Staining

Care must be taken during the polyjacking process to keep the foam off the surface of the concrete, as it can cause staining that is difficult to remove.

• Uncertain Void Fill

There is a possibility that not all voids under the settled concrete will be filled completely, potentially leading to a weaker repair.

• Potential Hazards

During the chemical reaction that causes the foam to expand and lift the settled concrete, there is a risk of melting or explosions.

What Is Stone Slurry Grout Concrete Leveling?

Stone slurry grout leveling is a concrete leveling process that involves pumping a mixture of crushed limestone, water, and sometimes Portland cement under the settled slabs.

As the mixture is pumped below the surface, it spreads out to fill voids and raise the settled slabs back to a level position. 

This concrete leveling method is often confused with mudjacking, but they are distinct processes.

Stone Slurry Grout Leveling Strengths and Weaknesses

Stone Slurry Grout Leveling Strengths

• Strength 

Stone slurry grout leveling is stronger than both foam leveling and mudjacking due to its ability to fill all voids and create a solid base for the slab.

• Control 

The slow stone slurry grout pumping process allows for precise control, making it suitable for complex repairs.

• Eco-Friendly 

The pumping compound used in stone slurry grout leveling is made with all-natural and environmentally friendly ingredients, ensuring a greener approach to concrete repair.

• Locally Sourced Materials

Stone slurry grout leveling utilizes locally sourced limestone, supporting local industries and reducing transportation costs.

Stone Slurry Grout Leveling Weaknesses

• Drill Hole Size

The drill holes for stone slurry grout leveling are larger compared to foam leveling, measuring 1" in diameter.

• Limited Accessibility 

Stone slurry grout leveling does not utilize mobile carts, meaning the job site must be within a 200-300 foot reach of the truck and hoses.

When to Choose Polyjacking

Polyjacking is ideal for decorative surfaces, like stamped concrete, due to the smaller, less noticeable drill holes.

It’s also better suited for smaller areas or locations that need fewer or smaller voids filled, due to the higher material costs.

Polyjacking may not provide sufficient strength to support heavy loads, making it better suited for non-weight-bearing areas, like sidewalks or patios.

When to Choose Stone Slurry Grout Leveling

Stone slurry grout leveling is great for both interior and exterior concrete slabs, making it an option for virtually any application.

Due to its lower material cost compared to polyjacking, stone slurry grout leveling is a good choice for larger-scale projects or when large voids need to be filled under the settled slabs.

If strength is a priority, such as in weight-bearing areas, stone slurry grout leveling is the better alternative to polyjacking. Also, in situations where control and precision are important, like around pools or A/C unit pads, it’s better to go with stone slurry grout leveling.

Which Repair Method Is Right for You?

Both polyjacking and stone slurry grout concrete leveling offer a convenient and cost-effective solution when compared to full concrete replacement, but it’s important to weigh the pros and cons of each option to figure out which method will be best for your specific project requirements.

While you should read and learn about each method on your own, it’s also a good idea to schedule inspections and cost estimates with as many concrete leveling companies as possible, as trustworthy and experienced professionals will be able to advise you on the best course of action.

Here at A-1, we believe in giving our customers the whole picture, rather than selling them a one-size-fits-all solution. For this reason, we have even more articles like this one in our online resource library, Concrete Academy, to help you learn as much as possible about your options.

These resources will help you learn more about polyjacking, stone slurry grout leveling, and mudjacking, which is worth exploring as an option as well, even though we don’t perform it here at A-1:

• All About Polyurethane Foam Concrete Leveling
• All About Stone Slurry Grout Concrete Leveling
• What Is Mudjacking?

If you are interested in seeing what polyjacking or stone slurry grout can do for your settled concrete, click the link below to schedule a free onsite cost estimate and concrete inspection with an A-1 expert!

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