polyurethane injection sites

When is Polyurethane Grout Rehabilitation an Effective Option?

The use of polyurethane grout rehabilitation for soil densification and structural rehabilitation has been revolutionizing the way public works managers and building managers think about rehabilitation vs. replacement. Due to cost-effectiveness and innovations in injection techniques, the viability of the solution has been “fast-expanding” and the applications are spanning across a variety of uses, such as roadway lifting, manhole and joint sealing, dam seepage barriers, seawall stabilization, and building foundation realignment. The question is, when does polyurethane grout make sense as a rehabilitation solution?

As you can imagine, this question is filled with a ton of variables, but we will try our best to identify typical rehabilitation opportunities and questions you should ask yourself around overall viability.

1.) Is the issue repairable via polyurethane injection?

The first thing to consider with this question is “Is the issue soil-related?” First and foremost, polyurethane injection is used to fill voids, whether large voids where no soil is present, or voids that exist between unconsolidated soils. The polymer is fast expanding, so once the voids are filled the polymer then compresses and densifies the soil and increases its weight-bearing capacity. So, if your problem is being caused by weak or weakening soils, then polyurethane may be an excellent solution.

CST polyurethane injection

2.) What is the condition of the structure being rehabilitated and what are your goals?

While we obviously think polyurethane injection is pretty great, the fact is, it isn’t a silver bullet. If the intended use of the structure is for continued use, the structure ought to be in a relatively operable condition. While we have been able to do amazing things with brick manholes that have lost grout, we are mainly focused on ensuring the structure can still meet current demands by rehabilitating the soil around or underneath the structure. But if the structure is crumbling or there is a focus on having the structure meet considerable volume increases, rehabilitation may not be a solution.

3.)  When considering sewer infrastructure, when is polyurethane applicable?

Polyurethane injection is highly adaptable when it comes to pipe and manhole joint rehabilitation. The reason is the application can be performed from inside the structure (access permitting) or from the surface.  The polymer is ideal for sealing leaking joints or stabilizing the structure.  Once injected, the polymer expands throughout the voids, sealing joints against Inflow and infiltration. In addition to sealing joints and filling voids, the polymer stabilizes the adjacent soil providing increased support for the structure and preventing future washout of the stabilized soil.

polyurethane injection in lateral line CST

As mentioned in item #2, the condition of the structure and its future requirements are a consideration when determining whether polyurethane injection is a viable rehabilitation option. That being said, groundwater leakage and inflow and infiltration can be a major cause of sanitary sewer overflows and, if mitigated, can result in better utilization of your actual wastewater flows and you may find your current designs to be more adequate than thought.

4.)  Can polyurethane injection be used to increase soil load-bearing capacity to handle heavier loads?

In short, the answer is yes, but it really depends on how much weight, the soil quality, and the nature of the geology and subsurface structures. There are several instances where we have helped repurpose foundations to handle dramatically increased loads, such as silos, cranes, heavy equipment and machinery, and structural support columns. In each instance, the injection approach was uniquely designed to take advantage of the current soil and geological makeup of the site.

CST polyurethane injection sites

Not every site is capable of load-bearing increases.  In sites with highly plastic soils, the polyurethane’s bearing increase becomes limited to the bearing capacity of polyurethane itself as it is unable to permeate the soil and cannot build structural integrity by mixing with the soils. For ideal bearing-capacity increase, the ability for the polymer to saturate and bind the soil into a contiguous structural layer must be available.  The injection design can help develop a bridging technique to help distribute the loads more evenly over the newly strengthened soil.

In short, polyurethane is an excellent rehabilitation solution when structural circumstances permit, and financial conditions make sense. When determining these issues, we recommend running an ROI analysis, developing rehabilitation, and having an injection approach designed which would meet your project goals.

Slab leveling

Slab Leveling: Top Five Most Common Customer Questions

Just like with any construction project, customers are going to have a variety of questions to help them understand how their project is going to go and what to expect from the contractor. This is no different when trying to determine if slab leveling with polyurethane is the right solution for their project. Here are a few common questions that customers have when evaluating the slab leveling process. 

  1. How does slab leveling with polyurethane work?

Slab leveling with polyurethane is a relatively simple procedure to understand.  The polyurethane is a specialized geotechnical system that is formulated to compact and densify soils with enough expansive capacity to lift concrete.When the polyurethane is injected below a slab it reestablishes contact between the slab and the soil, helping to transfer the load of the slab back into the soil.  Once the soil beneath the concrete is fully compacted and densified, injections are continued while closely monitoring the surface for movement.  The expansive force of the polyurethane then pushes upward and lifts the slab.  

  1. Does polyurethane slab leveling require excavation?

No excavation is required with slab leveling. The process works by drilling 5/8″ holes, less than the size of a penny, through the slab to give access for the polyurethane below the slab.  Once injections are complete, the holes are filled with a non-shrink grout to help deal with potential aesthetic issues.  

  1. How long does polyurethane slab leveling take?

Polyurethane slab leveling is a fast process. Geotechnical polyurethanes range in expansion and cure time, but they typically cure up to 95% capacity within 25 minutes. This means you can drive a car over the treated area within 25 minutes after injections are completed. The project length is dependent upon the size and scope of your project, but typical residential projects are completed in less than a day. 

  1. Does polyurethane harm the environment?

Since polyurethane is injected into the soil, it is reasonable to have concerns about the environmental impacts of the polymer.  Our geotechnical polyurethanes are environmentally inert, meaning they do not leach chemicals into soils or water.  In specialized formulations, our polyurethanes meet NSF-61 ANSI safe drinking water standards, meaning the polyurethane can be put in contact with drinking water without concern for contamination.  Polyurethane slab lifting also uses less energy thank rip out and replace and reduces greenhouse gas and landfill waste by extending the useful life of existing concrete.   

  1. What is the cost of polyurethane slab leveling?

It goes without saying that polyurethane slab leveling costs are dependent on the size of your project and site conditions.  However, in most cases when compared to the cost of replacement, polyurethane slab leveling is significantly less expensive.  When comparing with the cost of older slab lifting methods or rip out and replace, ancillary costs such as down time, removal of landscaping or irrigation systems, and interrupted access should be considered. 

If you have additional questions about the slab leveling process, contact us today for a free consultation on your concrete repair project.

Settled concrete sidewalks and walkways

Top 3 Benefits of Lifting Settled Concrete Sidewalks and Walkways

Settled concrete sidewalks and walkways can pose some serious risks that require attention. Sidewalks and walkways will begin to sink and shift over time as soil erosion and settlement occur. As a property owner, you have repair options to choose from to remedy these issues. A fast, effective, and affordable option to repair sinking sidewalks or walkways is with polyurethane concrete lifting. 

What Causes Concrete Sidewalks and Walkways to settle and shift?
Over time, concrete sidewalks and walkways will settle and shift naturally due to erosion and settling soil. Commonly, these things are caused by moisture from leaking pipes or weather events like rain, snow, or freezing. Tree roots growing beneath concrete slabs and digging rodents or other pests can also cause soil erosion.   Also, newly constructed concrete slabs may settle due to poorly compacted base soils beneath the concrete.  These areas may continue to densify and compact over the first few years following new construction.   

While it can be tempting to ignore the issue, there are some key benefits to having sunken or settled concrete sidewalks and walkways lifted before the problem gets worse and more expensive.  

  1. Safety Hazard Mitigation
    Lifting your settled concrete sidewalks and walkways can resolve trip hazards, a serious safety issue especially in areas that experience high pedestrian traffic. Uneven or misaligned concrete slabs pose a serious risk to public safety and major liability concern for public or private property owners, HOA’s, and municipalities. If neglected, sidewalk or walkway trip hazards could cost thousands in lawsuit settlements and legal fees. Polyurethane concrete lifting raises and levels sidewalks back to the correct grade, saving you from the consequences that may occufrom potential trips, falls, or injuries.
  2. Improving Water Drainage
    Sunken sidewalks and walkways can cause water to pool and prevent proper drainage. Improper water drainage can lead to further concrete damage due to soil disruption and erosion. If the problem is ignored long enough, it can eventually cause structural damage to the surrounding property. Over time, pooled water can cause concrete surfaces to deteriorate and weaken the integrity of the slab.Standing water also poses a risk to public health. In warm climates, standing water is a breeding ground for disease-carrying insects like mosquitos. Rodents seek out water sources near their nests, so an area that frequently pools with water may attract these pests and encourage them to nest in or around your property.  In addition to being a risk to our health, rodents and other pests can cause serious and often expensive structural damage. 

    3. Preserving Property Value
    Aside from the safety, health, and financial risks associated with sunken concrete sidewalks and walkways, there are also cosmetic benefits to lifting and leveling those concrete slabs. Well maintained sidewalks and walkways add value to a property and improve curb appeal.  Sunken concrete sidewalks and walkways can be a clue to potential buyers that the property was not well kept and could be a red flag for hidden issues.  If settled and uneven concrete slabs are left untreated, voids beneath the slabs may occur due to water infiltration.  Those voided areas create unstable support systems for the concrete and can cause concrete to shift and break.

Lifting concrete sidewalks and walkways with polyurethane is a costeffective, fast, and efficient solution that can improve safety conditions, drainage capabilities, and adds value to property while saving owners the headache and financial cost of additional, costly repairs in the future. Contact us today for a free consultation on your concrete lifting needs. 

Polyurethane foamjacking

Polyurethane Foamjacking: A Non-Disruptive Concrete Raising Solution 

Polyurethane foamjacking is a concrete raising solution that has captured a lot of attention over the past two decades and for good reason. The process has been deemed clean, fast, safe, and cost-effective. This article is meant to summarize what polyurethane foamjacking is and how the process is minimally disruptive for your concrete slab, your schedule, and your pocketbook. 

How Concrete Raising with Polyurethane Foamjacking Works  

Foamjacking works by addressing settlement, voids, and loose soils underneath a concrete slab with a high-density polyurethane. The concrete raising contractor injects the polyurethane through a 5/8″ hole that is drilled through the slab to give access to the void and weak soils underneath. The polyurethane initially enters the soil or void in liquid form. The material reacts and expands as it travels through the soil or void. Once the void is filled, the polyurethane densifies and recompacts the soil beneath the slab. Once soils are sufficiently compacted, the injection process is continued with careful monitoring until the pressure created by the polyurethane lifts the slab. With the right contractor, the slab can be lifted back to level, re-establishing contact between the soil and slab, and the weight load of the slab is reestablished back into the soil. 

How is Polyurethane Foamjacking Minimally Disruptive? 

Polyurethane Foamjacking requires no excavation and is very fast. The concrete raising solution only requires nickel-size holes to be drilled into the slab and that is it. After the injections are complete, the holes are filled with a non-shrink grout that hardens and is nearly imperceivable. The injection process is minimally disruptive and clean so you won’t be fretting over the condition of your concrete or yard. 

The speed of the concrete raising solution is also minimally disruptive to your time. Once the polyurethane is injected, it cures to 95% capacity within 20 minutes (you can drive your car over it!) A typical slab lifting project normally only takes a couple of hours to 1 day, depending on size and complexity. 

What About Costs? 

Concrete raising with polyurethane foamjacking is in most cases, less expensive than tearing out and replacing the concrete. This advanced technology helps save you money, extends the useful life of existing flatwork, and decreases disruption to your bank account! 

What Should You Do Now? 

Get a free estimate today! 


Concrete lifting contractor shakes hands with client

How to Find the Best Concrete Lifting Contractor in Your Area

Finding a qualified and professional contractor can seem like a daunting task. With these tips, you’ll be on the right track to find the best concrete lifting contractor in your area to handle your concrete repair project.

Ask Friends & Family for Referrals

One of the best ways to ensure that you find a qualified and professional concrete lifting contractor to resolve your sinking concrete is simply by asking people in your network for references. Concrete issues are common, so chances are you know someone who’s had to have a similar problem addressed. Talk with friends, family, and coworkers to see who has performed work for them.

You can also expand your network by asking friends, family, or coworkers if they know someone that has had to have concrete lifting work performed. The people just outside of your network may have different experiences with the same contractors recommended by friends or family, or they may know of someone else who’s done a similarly good job for less cost. There are great opportunities to see completed work in person which is more reliable than photos you might see on a contractor’s website.

Google Concrete Contractors in Your Area

Speaking of contractor websites, this might be an obvious solution, but it’s a great idea to start your contractor search online. Check out some of the top-ranking listings for concrete lifting contractors in your area, but keep in mind, just because they show up at the top of your search engine doesn’t mean that they’re the best. Make sure to look at reviews on Google in addition to social media sites like Facebook and LinkedIn. It’s also a good idea to check out contractor review sites like Angie’s List and Home Advisor. These sites and the reviews they contain can help you catch on to any potential red flags and give you a better idea of who is the best contractor for your job.

When you find a few highly reviewed contractors, go ahead and check out their websites. Look at some of the projects they’ve done that are similar to the issue you have with your concrete and check out before and after photos to visually judge the quality of their work. Many contractors will also have videos available that can help you understand the process of their concrete repair solutions.

Schedule a Consultation with a Concrete Lifting Contractor

After you’ve done your research with your network and the internet, the next thing you can do to ensure you’re hiring the best concrete lifting contractor is simply to schedule a consultation. Many contractors offer free consultations, and it’s a great opportunity to ask a series of questions that can tell you if the contractor you’re considering is the best person for the job.

One of the best questions to ask is how long the contractor has been in business performing work similar to the job you need done. Knowledge and training can go a long way, but nothing beats time tested experience. A reputable contractor should also be willing to provide their license and insurance information, so if they don’t offer it up front, be sure to request it. Before committing to hiring them, double-check with your local Division of Occupational and Professional Licensing to verify the contractor’s license and insurance.

Finally, verbal agreements are hard to enforce so after deciding on the perfect contractor for your concrete lifting job, be sure to ask for the cost estimate and contract agreement, including any discussed warranties, in writing. A reputable contractor should provide everything in writing even if you don’t ask. This ensures that both you and the contractor have a recorded agreement, protecting both parties.

Following these steps will turn the daunting task of finding the best concrete lifting contractor into a much easier process. Remember to start by looking at referrals from your network of friends, family, and coworkers. You can extend your network by asking people within your network if they know someone who’s had similar work done. Check reviews and contractor websites online, don’t just rely on the top-ranking listings to tell you which contractor is the best. Schedule consultations with contractors you like, request their licensing and insurance information, and double-check with your local Division of Occupational and Professional Licensing to confirm their validity. Lastly, remember to get any estimates, agreements, contracts, and warranties in writing.


If you’re in need of a contractor, there’s no better place to start than Concrete Stabilization Technologies, Inc. Contact us today for a free consultation on your concrete repair needs. We are proud to service the entire United States and have offices located in:

  • Denver, CO
  • Salt Lake City, UT
  • Wheatland, WY
  • Montana
  • Waukee, IA
Concrete raising with polyurethane foam jacking

Concrete Raising with Foam Jacking

You’ve probably stumbled across uneven concrete slabs in your neighborhood. This is a common problem, especially if the concrete slabs are placed over soft ground. Fixing this issue isn’t as complex it may seem because replacement isn’t the only option. Concrete raising is a cheaper option as opposed to replacing concrete. One of the ways concrete is raised is by using polyurethane foam, a foam that expands instantly. This process is known as polyurethane foam jacking. Read on to learn more about how foam polyurethane can be used to aid in concrete raising.

Soil Load-Bearing Capacity

Another crucial aspect of concrete raising is soil load-bearing capacity. If the soils are weak or unconsolidated the weight-bearing ability of foam polyurethane isn’t effectively distributed into the ground. This is due to the fact that the soil, if not densified, will inevitably slip under the weight of the concrete. This, in turn, causes the concrete to become uneven once again. If soil densification is determined to be a necessary process, it’ll look something like this:

A lengthy inspection will be done to determine where the injections must be done in order to effectively densify the soil. A large 3-5ft square grid pattern will be laid out where the injections will be done at multiple depths.

The initial injections are completed at the top level in order to condense and strengthen the soil and use the concrete slab as a way of consolidating the top layers for the lower injections to work against.

The remaining injections are shot from the top-down, with each lower layer having the capability to densify against the denser top layers. This strengthens the overall weight-bearing ability and ensures that the slab will not slip back down by consolidating the lower soils over time.

Choosing The Right Type

There are two main types of foams that are used for concrete raising. The reactivity and density of the foam need to be determined before moving on with the concrete raising process. Here’s a guide to the two factors that come into play:


A foam that reacts slowly is typically used when a large void needs to be filled. The foam will spread evenly and thicker, allowing for more coverage. A foam that reacts quickly won’t spread evenly and won’t have the same amount of spread that is offered with a slow reaction. Having control allows the workers to ensure that the slab isn’t raised too much and lines up precisely with the other slab. This ensures the success of the concrete raising process.


A foam that is much denser will be used if a larger weight needs to be born. If the slab doesn’t weigh as much and the void is large, a foam with a lower density will be used to fill in the void easier. Density is important to keep in mind as this determines the success of the operation and whether or not the polyurethane will be able to hold the weight of the concrete slab.

For Your Understanding

In short, though concrete raising is based around the environment, there is a basic process to it. Because polyurethane can be used to lift concrete in almost any area including foundation, sidewalks, driveways, steps, garages, pool decks, etc. it’s important to gauge the environment and reasons why the concrete slabs are uneven to begin with. This information will determine what kind of polyurethane will be used and what style of injection will be done. Slow reaction polyurethane is typically used for large voids to increase the spread and ensure an even rise. Density is also a factor that will be determined based on how much weight the polyurethane needs to bear. Polyurethane jacking is the most effective form of concrete raising and is far superior to replacing concrete altogether.