Concrete Raising

Concrete Raising

Concrete Raising

Concrete raising saves 50% of the costs in comparison to concrete replacement. It raises concrete slabs and proceeds to the filling of void spaces beneath them.

Polyurethane foam is hydrophobic, impervious to water, and cures in one hour after its injection.

Restoring the preexisting concrete by pumping a liquid beneath the slab to elevate it to its starting state.

It’s feasible to employ a high-density polymer to raise, level, and consolidate your settling concrete slabs. The greatest thing is that it is a fast, convenient, and affordable alternative for your house.

Foam-raising concrete is a long-term fix that may save you money. Especially if you are thinking of putting your house on the market and want to make your concrete seem better right now. The whole procedure is explained in detail further down the page.

Concrete RaisingPoly FoamMudjackingConcrete Replacement
Long LastingYes Yes
Economical Yes Yes
Completed in a few hours Yes Yes
No Disruption to Landscape Yes Yes Depends on each project
Cosmetically Appealing Yes Yes Yes

Reasons For Concrete Sinking And the Requirement For Concrete Raising

Even though concrete is a long-lasting substance, the earth underneath it may cause it to move and sink over time. This is particularly true in areas with erratic seasonal cycles like those seen in the tropics.

It is possible for your concrete to sink and fracture over time. If the concrete was poured on top of dirt or stone that was not adequately compacted, this might happen much faster.

Another culprit is water. It steadily eats away at the foundation material by penetrating surface fractures.

You may be putting off concrete repairs because of the expense. Left ignored, cracked and sunken concrete may lead to tripping hazards and other issues with your property, especially if water accumulates.

If you are considering selling your home, the appearance of concrete may impede your ability to do so. This look can have a negative effect on its curb appeal, which in turn may make it harder for people to make offers.

Concrete is used in all types of construction projects, but it will start to shift over time. Concrete is made up of sand, gravel, water, and cement. Over time the water molecules will begin to evaporate out of the concrete leaving the parts that are heavier than concrete behind. This causes concrete to start cracking or shifting with the ground beneath it.

Concrete Raising With Foam

While the most obvious solution in the past was to simply to perform a replacement of the affected concrete surfaces, there is a cheaper and very effective solution through the injection of poly foam. Let´s see it in detail.

Polyurethane Foam is injected into pre-existing concrete slabs through tiny holes that are created in the floor. By dislodging air pockets and water or moisture-saturated material from under the slab and raising it to a new level, a hard permanent subgrade is formed.

Comparable to mudjacking, but with better long-term outcomes and with less disruption to the environment. As the high-density polymer is injected under a sunken concrete slab, the system raises and stabilizes the soil at the same time. When compared to typical mudjacking, the polymer is lightweight and exceptionally robust, making it a longer-lasting repairing solution.

A sunken concrete slab is a common occurrence in homes and businesses. It happens due to ground settlement, foundation subsidence, or soil shrinkage. These slabs can be fixed using a technique called mudjacking. This process is similar to raising sunken walls but the results are temporary and not as durable as traditional methods of fixing a slab. The system works by injecting high-density polymer below the slab to raise the height of the surface and then cover it with a topping material such as asphalt, concrete, or paving stones.

When it comes to repairing concrete, using foam or polyurethane products to raise it is an excellent option. Besides extending the lifespan of your concrete, this method also saves you both time and money in the process.

You will also save money and lessen your environmental imprint if you raise your concrete rather than replace it.

The PolyLifting system’s outcomes will stay far longer than mudjacking. Using a polymer that is both light and robust reduces the risk of material shifting. As a result, it is a fantastic option.

It also saves a considerable amount of time. In contrast to mudjacking, polyurethane may be utilized immediately upon installation.

Concrete Raising Process

Injecting the polymer foam under the sinking concrete slab is how it works. This allows it to ascend to its suitable location. It also facilitates loose soil. Once finished after only a few hours, the concrete may be utilized again immediately after it cures.

The end result is a concrete floor that is level and smooth. Only dime-sized holes are utilized to inject the polymer. As a result, they are hard to spot.

Do you want to learn how to do it? The whole procedure is fast and uncomplicated. Therefore you won’t have to disturb your normal routine to get it done. Let us demonstrate how easy it is.

Visit from Professional Estimator

Before work begins a trained professional estimator will visit your property to take a look at your concrete. He or she will determine what’s causing the settlement. Measurements are also taken so that a cost estimate can be provided.

It begins with our trained professional estimator visiting the site, evaluating the possible cause for the settlement, taking measurements and then generating a detailed estimate. This can be done without needing to be home unless it’s an interior slab.

If it’s a concrete slab located outside, then you won’t even need to be home for the estimate to be done.

Drill Concrete

Once you have obtained the quote and agreed to the process, professionals will come to drill little 5/8″ perforations onto the recessed slab. This is deliberately accomplished with the goal of minimizing fracturing while ensuring the foam is poured in the precise spots.

So let´s put it clearly:

Small 5/8″ dime-sized holes are carefully bored onto the sunken slab once the team arrives. Due to the modest size of the orifices, they are hardly noticeable once completed, and there is little possibility of the slab splitting.

Injection Of The Foam Into The Cavity

For the following stage, the polyurethane fluid will be injected into each of the holes in order to seal them. When inside, the liquid condenses into a foam and expands to cover any open spaces or holes. This will immediately strengthen the poor soil and elevate the sinking slab.

So the technician now gently introduces a two-part liquid polymer into each one of the orifices.  The liquid transforms to expandable foam when it is combined underneath the slab, swiftly filling open gaps, strengthening weak soil, and elevating the slab.

Patching The Holes Drilled

After the polyurethane foam or the cement slurry, or any similar mixture is poured successfully into the drilled cavity, the service contractor will complete the concrete raising process filling the voids of the drills done at the beginning.

When the concrete slabs are thoroughly levelled and stabilised it is the professional turn to proceed with filling of each little orifice with grout. This will create a long-lasting, watertight seal on your concrete.

A long-lasting tight seal is achieved by having the technician plug each little hole in the concrete slabs after they have been leveled and stabilized. Concrete is now raised and the fix is barely evident.

Curation Process

It takes about fifteen minutes for the polyfoam to cure. Some mixtures can cure in up to an hour. However, in a short period of time after the concrete raising, the surface is ready to be utilized by pedestrians or automobiles.

Concrete Raising Pros And Cons

Pros

Concrete raising is much cheaper than concrete replacement: The cost of concrete raising is on average 58% lower than the concrete replacement for the same surface footprint. Sometimes it can reach near 70% lower than replacement.

Fast process: It is completed in a bit less than a working day. All materials are mixed on-site and injected.

Superior waterproofing in comparison with mudjacking: When it comes to waterproofing, ordinary mudjacking substance fails miserably. As a result, subsequent degradation and settlement are less likely.

Does not add more weight to the soil: Despite its strength, expandable polyurethane foam is easy on the environment since it does not add density to the already unstable soil.

Immediate Use – In most cases, concrete repaired through concrete raising can be used almost immediately following the completion of the job. In contrast, new or replaced concrete has to cure for a minimum of 28 days.

Long-term Fix – Concrete slabs raised with our cementitious slurry or polyurethane foam can carry a warranty of up to 2 years. The length of warranty depends on soil conditions, drainage and other factors. The polyurethane material will not shrink, breakdown or wash-away like cement or mud-based materials can overtime.

Very Small Injection Holes Required: Since Polyurethane begin as a liquid, much smaller holes are needed (penny-sized) compared to mudjacking (golf ball sized)

No Disruption to Surrounding Landscape – No need to repair surrounding areas of grass, trees, and/or shrubbery as you would have to with concrete replacement.

Reduce Liability – Eliminate trip hazards, excessive step height, improper pitch of slabs.

No Environmental Impact – Green! – Landfill legislation in many parts of the country lists old concrete as Hazardous Waste, adding an additional recycling cost to those choosing to replace concrete (for both the operator and the customer).

Improves Curb Appeal: If the concrete raising is performed in a visible part of your property, such as a driveway or a sidewalk, it will clearly look much better. This is also an advantage of concrete replacement.

Cons

I could not find any disadvantage for the concrete raising process. It is much cheaper and faster than the alternative of concrete replacement. It also cures quicker and can maintain longer.

Concrete Raising Cost

Concrete raising is typically about half the cost of replacing the same concrete.  Ultimately, the cost of raising or stabilizing concrete is a direct reflection of how much material the project will take.  A simple project to raise a slab of concrete will cost less than, if there is a large void under the slab requiring more material.  In general terms, concrete raising can cost between $2-$5 per square foot.

For example: a 10 ft. x 10 ft. section needs to be raise is 100 square feet.  This job could cost between $200 and $500 to repair.  Depending on how far the slab is settled, if there are voids present, or if other sections need to be involved in the repair, will determine where in the scale the job would be bid. 

Raising concrete is an extremely affordable option when compared to replacement. Since every job is unique in terms of the amount of material needed and the size of the area being raised, giving an average cost is difficult. 

In general, raising concrete with polyurethane is typically 50%-80% less than replacement.  The size of the area and the amount it has sunk are the biggest factors that determine the price.   

Fill a form to obtain FREE estimates, so a seasoned estimator can look at your project, and provide you with an accurate estimate of what it will cost to complete your specific project.

Mudjacking As A Variant Of Concrete Raising

In this technique of concrete raising, there is no polyurethane foam injection. I was recommending it until our 2022 update of this article. Since then, I consider that the poly foam injection is better for concrete raising.

In the past, mudjacking was the only method available for homeowners looking to lift and level their sunken concrete. Mudjacking, which works by pumping a cement and sand slurry below a slab to lift it back up. Mudjacking has been a popular method in the past however it was never regarded as a long-term solution since the slurry material tends to break down over time and the heavy weight of the material can cause the slab to re-settle again.  It also required drilling large 1″-2″ holes into the concrete which didnt look too great and weakened the slab. To solve these issues polyurethane foam is now the preferred materiel to be used when lifting and stabilizing concrete.

An experienced mudjacking contractor knows how important it is to pump the proper thickness of mud slurry. Often, the thickness is changed several times when raising a slab correctly.

Some contractors have a transportable pumping device that is specifically envisaged for mudjacking.

With our shorter pump hose, we can change the thickness of our slurry much faster and more efficiently. Others are stuck with a lot of material in a long hose that could be the wrong thickness. Pumping the wrong thickness of slurry often leaves cavities under the slab and could even break the slab during concrete leveling.

Scope Of Work For Concrete Raising

Concrete raising or lifting, can be performed in any flooring concrete arrangement.

You can raise, level and stabilize sidewalks, curbs, gutters, streets, highways, parking lots, garage floors, patios, pool decks, industrial floors, bridge approaches, basketball courts. 

In essence, most any residential, commercial/industrial, and/or municipal concrete slab on grade can be raised, levelled and stabilized.

Longevity Of Concrete Raising

Polyurethane since it’s a synthetic material, will not change shape or breakdown like other materials such as sand or cement. However, the ground can and will move overtime depending on soil conditions, especially with the frost cycles we experience here in the Midwest.   Also, water intrusion from poor drainage can erode the soil, which can cause re-settling.   Lastly, a long dry spell over the summer can cause the ground the shrink, which can impact your concrete. So typically if there is any re-settling it’s most likely due to soil conditions, poor drainage or extreme weather all of which would also affect new concrete. 

Concrete Raising vs Replacement Of The Existing Concrete

Polyurethane injection (PolyLift) to be most effective alternative to replacement. Below are the reasons why concrete raising may be a better choice for repairing sunken concrete.

  • Very Affordable: Raising concrete is normally around 50% to 70% less than having it replaced!
  • Quick: Our raising process can be completed in 30-60minutes compared to days with replacement.
  • Less Hassle: No need for permits, inspections, landscape restoration and all the noise, dust and other things that are part of the concrete construction.
  • Green: If are trying to do your part to minimize your environmental footprint, then raising your concrete rather than replacing it is one way to do it.

Of course, not all concrete can be raised. Raising may not be a viable options when there is a large amount of cracking and/or surface wear.

Mudjacking vs Foam For Concrete Raising

 there are a number of advantages to using polyurethane vs mudjacking to raise concrete in regards to appearance, longevity and process. Read below to learn why more and more homeowners and property managers are using polyurethane to raise and level their sunken concrete.

Both methods will certainly lift and level your concrete however there are many advantages to using polyurethane over mudjacking. Below are the main advantages and benefits to using polyurethane over mudjacking:

Appearance

Smaller Injection Holes: A key benefit many property owners love about using polyurethane to repair concrete compared to mudjacking are the smaller holes that are required. Our polyurethane method only requires 5/8” holes (the size of a penny) compared to 1”-2” size holes needed for mudjacking. Our process produces a nearly invisible end result. This is especially important when repairing decorative stamped concrete.

Fewer Holes: Our polyurethane foam needs fewer holes to be drilled in your concrete for a cleaner look compared to mudjacking. Because polyurethane foam is sprayed below the slab as a highly pressurized liquid, we can cover a larger area from each injection port. The foam can flow and expand from 4 to 15 feet from each injection port. Since mudjacking uses a heavy slurry, only 1-2 feet can be covered below the slab from each hole. This means more holes are needed to raise and level concrete when using mudjacking. Those who prefer their concrete to not look like Swiss cheese after it’s raised prefer using the polyurethane method.

Longevity Of Foam Injection vs Mudjacking

Lightweight: Mudjacking uses a grout made of sand, cement, and water. On average this can weight around 100lbs per cubic foot. This heavy material can put more burden on an already weak base which can cause future settling to occur. Polyurethane on the other hand only weighs 2lbs per cubic foot. Which means our lightweight material will put much less (about 50 times less!) weight on your base which decreases the chance of future settling when compared to mudjacking.

Non-Shrinking Material: polyurethane material is made from environmentally safe materials and becomes an inert, high-density solid material minutes after it’s injected and will forever keep its shape and strength. Mudjacking, on the other hand, is made from water, sand, and cement, which means it can shrink, wash away and can be susceptible to moisture and erosion.

Process Execution

Cleaner: Our material is contained in our specialized trailer, it is then pumped to each injection port through a hose. That’s it! Unlike mud jacking, there is no need for heavy equipment to be used on your property and messy grout spills to be cleaned. Also, since our holes are so small, there is less dust created compared to mudjacking. Of course, any dust that we do create is quickly vacuumed up!

Faster: Once the polyurethane is pumped in it only needs 15 minutes to cure before it’s ready for cars to drive over the concrete. No need to wait days to get your car back in your garage, which is the case with mudjacking. Business owners can also allow customers and employees to use the area immediately after we leave. A much cleaner process and the area is usable 15 minutes after installation vs 24 hours with mudjacking

concrete raising
In this isometric view, the service technician is completing the injection of foam inside the concrete. The next step will be to fill the voids produced by the drilling performed at the beginning of the concrete raising process. Source Shutterstock

Contractors who argue that mudjacking is the best method are either misinformed or are just reluctant to update their equipment and process.

Concrete Sinking Again After The Raising

The great thing about using a polyurethane foam is that it’s a synthetic material that will not breakdown or change shape.

Since polyurethane is extremely lighter than mudjacking material the chance of re-settling is greatly reduced.

That reduces the likelihood of your concrete sinking at the same rate.

However, just like new concrete, changes in soil conditions can happen due to frost cycles, poor drainage, or erosion. This can cause your concrete to sink over time.

The key to preventing concrete from sinking is by filling voids and keeping water away. Open voids below your concrete should be stabilized with polyurethane foam. All open gaps such as cracks and expansion joints should be caulked to stop water from getting below the slab and eroding the base. Also, all water should be directed away from your concrete such as downspout. The sides of your concrete should also be properly graded so that the base cant wash away. 

The best way to prevent your concrete from sinking once it’s treated with foam is to keep water away. This can be done by redirecting water using a downspout. You should also grade the sides of your concrete properly so that the base can’t wash away.

Continue to maintain your concrete for longer by filling voids with polyurethane foam. You should also make sure gaps and expansion joints are caulked to stop water from getting beneath the slab.

Photo of author

BY M. Kogan

Hello, I am Marcio. I am an architect and designer, alma mater is Mackenzie. Retired in theory, but an architect never retires completely. Along with architectural projects, I am a filmmaker and have completed some short documentaries. Filmmaking and design are my passions. In HomeQN I write about home decoration and foundations. The goal is to teach homeowners to DYI as much as possible, and when this is not possible, enable them through knowledge, to evaluate service quotations and choose the best service technicians.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.