The superior polyurethane method is required over mudjacking techniques for large DOT Highway projects.
Frequently, the scope of work of concrete lifting is simply to fill some voids in the concrete produced through cracking. Even in these cases, slabjacking is a preferred technique instead of mudjacking.
I recommended mudjacking in previous versions of this article, but after the 2022 update I started to suggest the readers to opt for slabjacking as a methodology for concrete lifting. Homeowners should negotiate this with the prospective service contractorduring the quotation process.
Concrete lifting is a time tested alternative to replacing sunken or uneven concrete, restoring sunken concrete slabs to their original grade at a fraction of the cost of replacement
Concrete slabs are an essential component when you’re building a home. Not necessarily for the home itself- although many homes do have a slab foundation- but for everything around your home. You have one or more of the following: sidewalks, patios, driveways, porches, steps… There may also be a slab beneath your air conditioner or as the base of a retaining/privacy wall.
When these slabs crack, shift, or sink, they create problems. Uneven concrete can be a trip hazard, it can collect water, and it can redirect water in an unwanted direction.
Raising sunken concrete through slab jacking extends the life of your concrete and prevents the need for replacement.
Concrete lifting is also an eco-friendly solution as it allows existing concrete to be leveled with no need to dispose of old materials and avoids wasted excess material as our materials are mixed on site and used as needed. The same process used for lifting concrete can be used as a preventative measure by filling voids beneath the concrete caused by settling or collapsible soil before the concrete settles and possibly breaks.
Slabjacking vs Mudjacking As Concrete Lifting Methodologies
Concrete lifting returns a concrete slab back to its original position by filling the ground beneath it. There are two methods of concrete lifting available: mudjacking and slabjacking. Both are cheaper and faster than tearing out and replacing the concrete. They are also less invasive and damaging to your landscape and property.
eliminates the color difference between new and old concrete.
|Material||Concrete slurry: a mix of limestone, concrete, sand, and water||Polyurethane foam|
|Drill size||1 to 1.5 inches||⅜ of an inch|
|Curing time||Hours or days, depending on quantity of material||Less than an hour|
|Durability||5-10 years||In most cases, permanent|
|Potential issues||Like concrete, it can decay, break apart, erode or sink||Can sink if soil erosion is significant underneath the injected foam.|
|Warranty offered||1-5 years||5 years|
Mudjacking uses water in the mix, and this makes it susceptible to the effects of weather. It can freeze, which means it cannot be used if the air temperature is at or below freezing. Slabjacking can be done unless the actual ground is frozen, regardless of air temperature.
By using polyurethane injection foam, we can raise your concrete to provide a sturdy, permanent solution to sinking concrete. It’s cleaner, too – we use 5/8″ holes to inject our foam, as opposed to 1 ½ – 2″ holes for traditional mudjacking operations.
compared to concrete replacement, the process of raising concrete with polyurethane foam is inexpensive (compared to the alternatives), and is exponentially faster than replacing the concrete.
The foam used in slabjacking begins as a liquid, so it can be injected through a much smaller hose than mudjacking slurry. Once the slabjacking liquid begins to foam and react, it sets up within minutes.
Slabjacking can be a permanent solution, if the cause of the sinking is corrected. For example, let’s say your sidewalk is sinking because a downspout drains next to it. If you extend the downspout so the water drains into your yard, the sidewalk should remain in place (once slabjacking is completed). Mudjacking uses a diluted version of concrete, which can degrade or erode over time. This is why the warranties differ between the two methods.
Mudjacking As An Alternative
Mudjacking is a method used to raise sinking concrete by pumping a mortar-based mixture beneath the uneven concrete slab.
The injected material is made of water, limestone, sand and Portland cement that eventually cures, becoming a solid and stable filling material. The fill is more stable than the soil, yet lighter than the concrete.
It is a concretecl lifting process that is done by injecting material beneath the concrete until it is lifted back into a level position. Mudjacking uses a grout mixture to fill voids beneath concrete and then uses additional grout to push the concrete slab upward to create a level surface.
The process of mudjacking for concrete lifting is quite simple.
A series of holes are drilled in an existing slab of concrete, a custom slurry mix is pumped under settled concrete slabs, stabilizing the subsoil, filling the follow areas under the slabs and lifting the concrete to it’s original grade. The holes are then patched with cement leaving a strong, permanent support under the concrete surface.
Polyurethane Foam Injection For Concrete Lifting
Mudjacking has been the industry standard for concrete leveling for many years. It utilizes a clay/mud material pumped beneath the concrete slab to achieve lift. Mudjacking requires a 2″ hole to inject material and, like concrete, can take several hours or even days for the material to fully cure.
Polyurethane injections are quickly replacing the tradition mudjacking as it requires a smaller injection hole of about 0.5″, cures in a matter of minutes, and carries a much lower risk of additional settling later due to its light weight properties. Polyurethane injections use a two-part mixture injected beneath the concrete to create an expanding foam to achieve lift. By the time the technician has finished lifting and cleaning up the work area the material is already cured and safe for regular traffic again. Polyurethane is less likely to experience additional settling later as it is very lightweight and the material does not break down or wash away with moisture.
Polyurethane injections are quickly becoming the industry standard as it causes less cosmetic damage to the concrete and uses lighter weight materials than traditional mudjacking. Both methods are guaranteed solutions to level concrete and are more cost effective than concrete replacement.
Polyurethane foam injection lifts uneven, sunken, cracked concrete.
Unlike traditional invasive concrete repair methods such as mudjacking and concrete replacement, polyurethane foam injection utilizes high-density polymers to stabilize and lift concrete.
Polyurethane foam injection is both lightweight and durable and is able to support and lift sunken concrete without any extra added weight.
Polyurethane foam injection provides an affordable and less invasive solution to your sunken, cracked, uneven concrete issues.
Rather than using a mixture of concrete and mud, polyurethane foam injection uses high-density polymers to raise concrete slabs using a simple 4-step process:
- Step 1 – Penny-sized holes are drilled in the concrete slab
- Step 2 – Foam injection ports are installed
- Step 3 – Expansive polyurethane foam is injected to support and lift the slab
- Step 4 – The drilled holes are patched and smoothed out
Pros And Cons Of Concrete Lifting Using Polyurethane Foam Injection
- Fast-acting: Reaches its final strength and is ready to support weight within 15 minutes
- Noninvasive: Less messy than the mixture of concrete and mud used in mudjacking
- Lightweight- Weighs 4-6 lbs. per cubic foot when installed, which is significantly less than the 120 lbs. per cubic foot as typical fill material
- Waterproof – Cannot be washed out and is not affected by freeze and thaw cycles
- Precise & Accurate Lift – foam reaction time provides target lifting operation
- Environmentally friendly – Foam does not react with soil and does not release harmful chemicals
Polyurethane can cure in warm, cool, and even wet conditions. There are very few scenarios that concrete lifting is not recommended. One example of concrete lifting not being recommended is if a slab is cracked into multiple small pieces as it becomes very difficult to lift all of the pieces evenly. Concrete leveling is not recommended when the weather is below-freezing and the ground has frozen.
Usage Of Polycrete For Concrete Lifting
Similar to mudjacking, “poly jacking” is a concrete lifting process that is done by injecting POLYcrete,a two-part polyurethane mixture, beneath the concrete slab. When the two parts are combined it creates a rapid expansion of foam that lifts concrete in the same way that mudjacking does.
Concrete Sinking Reasons
The most common reason for concrete to settle is due to moisture. As the soil beneath the concrete gets wet and dries out it compacts the soil or leave voids in the soil that allow the concrete to settle. To avoid settled concrete, it is recommended to correct drainage near the concrete by extending your rain gutters away from the concrete and maintaining a positive grade. Soil can also compact due to the weight of traffic using the concrete surface or it can settle naturally over time.
The concrete around your home sinks for a number of reasons. The most common causes are: changing soil conditions, improperly compressed soils, erosions from downspouts or drains, and uneven weight distribution. If left untreated, you may need to replace the sunken concrete, which can be expensive, messy, and leave you unable to use the concrete during the repair.
Concrete Sinking Again After The Lifting
Within the first few years after concrete has been poured the soil compacts naturally and will not experience such a dramatic compaction again unless the soil is disturbed, flooded, or significant weight is added. Concrete corrected by mudjacking is more likely to experience additional settling than concrete corrected by polyurethane injection because the material used is not only adding up to 150 pounds per cubic foot to the void beneath the concrete, but it can also be washed away and broken down. Polyurethane injections are less likely to experience additional settling as the material weighs in at about 2 pounds per cubic foot and is hydrophobic so it will not break down or wash away due to the weather.
Advantages Of Concrete Lifting
You can raise your concrete for less than half the price of replacing the concrete slab.
Eye sores and additional structural cracks can be the result of unlevel concrete. When a concrete slab settles, consequently, doors and windows stick and structures connected to the slab may crack and settle as well.
Trying to sell your home? First appearances is everything to a home buyer.
Water damage: Water follows the path of least resistance and a settled or sunken driveway may end up costing a homeowner more money over time in foundational repairs.
Raising concrete with polyurethane foam often takes a couple of hours and is ready immediately upon completion.
Concrete Lifting Scope Of Work
Essentially, we can raise any form of concrete slab. Solid slabs of concrete can be raised and stabilized. Gravel areas or blacktop are unable to be repaired, and need to be replaced or re-installed to remedy settling issues. Slabs of concrete that are badly cracked may also be too damaged to lift.
The scope of work for concrete lifting can include pool decks, sidewalks, void fills almost anywhere, driveways, core fills in general, commercial and industrial floors, steps, gutters, curbs, terraces and patios.
Concrete Lifting Cost
“How much does concrete lifting and leveling cost?” Although there isn’t an easy cookie-cutter answer, on average, the cost of lifting and leveling your concrete is between $7.00 and $12.00 per pound of polyurethane foam depending on a few additional factors:
- Scope of Work
- Size of the Void
- Access to Work Area
Let’s review the average price of concrete lifting and leveling and break down factors that could affect your price. Keep in mind that when you are looking to invest in your property, it’s a good idea to get a couple of quotes from different contractors.
Costs of Leveling Concrete
The average cost to have a property owner’s concrete leveled is between $548 – $1,341. Other sources site the average cost is $2 – $5 per square foot. While that may give you a decent idea where your costs might fall, we can dig into it a little deeper. For this article we will concentrate on concrete lifting and leveling utilizing polyurethane foam.
The cost of lifting and leveling your concrete is all based on volume. Meaning, the cost is primarily based on the cubic feet or cubic yards of material that will be required to level your concrete. This is a little more confusing than simply calculating square footage, in addition to the area, we need to consider the depth.
For example, a typical sidewalk section is 5’ x 5’, equaling 25 square feet. Now consider how deep the sidewalk section has settled. Say it has settled 1” on all four sides of the section in question. Multiple the 25 square feet by the 1” (0.083’) of depth and you will get 2.075 cubic feet or converting that into cubic yards (divide by 27) equals 0.077 cubic yards.
Depending on the density of polyurethane foam the contractor is using, they will convert the cubic yards required into the required pounds of polyurethane foam needed to fill the space to level the concrete. An average density of polyurethane foam is 120 pounds per cubic yard. Multiplying the cubic yards required by the material density will tell you how many pounds of foam are required.
So, 120#/cy x 0.077cy = 9.24 pounds of polyurethane foam needed. Most contractors will base their cost to you on a range of $7 – $12 per pound of foam required. So, this section of sidewalk slab would cost between $64.68 – $110.88. Yet, there are other factors that contribute to the cost of leveling you concrete.
How the Size of Your Concrete Affects Cost
It would be tough for contractors to survive if they went out and installed a whole bunch of $64.68 projects. Therefore, some contractors will set minimum prices regardless of the amount of work or material required.
Successful contractors will be able to defray the minimum service cost by grouping multiple projects in your area to be performed on the same day so they can service the small and large projects without minimum costs.
The opposite end of the spectrum is also true, meaning that there are economies of scale for the larger projects. Each project has a minimum amount of set up and break down time. Larger projects will have a lower cost per pound as the costs for setting up and tearing down are spread over a larger volume of work.
How Concrete Void/Gaps Affect Cost
Again, the primary cost driver is volume. The greater the elevation of lift that is required, the higher the price will be. A project with a bunch of slabs that only need lifted ½” will be far less than a project that needs the same number of slabs lifted 3”.
Another consideration beyond the distance in elevation between the slabs is if there is a void under the area in question. Some slabs may only settle 2” and get hung up on something but there will be a 4” void under the slab that may have been caused by flooding or water runoff. The entire void would need to be filled to be able to successfully lift and level the slab in question. In this example, the number of pounds required would be based on a total of 6”.
Experienced contractors will be able to recognize the necessity to consider the additionally void fill. Although, there are some instances where the void is completely unforeseen. At this point, the contractor and owner would need to discuss what the additional requirements are prior to proceeding with the work.
How the Access To Your Concrete Area Affects Cost
The projects that are smaller in size might be the sidewalk slab immediately adjacent to road making set up and access very simple. The same size project maybe at the rear of the house, down steps and around the pool. The contractor will need to consider the additional time it is going to take to reach the work site. Others may be in a confined area right next to a wood deck making it difficult to access the slab, requiring more time to complete the project.
How Weather Conditions Can Affect The Cost of Your Project
The climate where your project is located and time of year will have an impact on your cost.
If you live in the southern and southwestern temperate climates, contractors are able to work all year long and can defray their operating costs over more projects, therefore, reducing their price per pound of material compared to contractors in the northern climates where most can only work 9-10 months per year.
The temperature of the soil or substrate can also have an impact on your costs. As the soil temperature decreases in the northern regions, the yield of the polyurethane foam decreases, requiring contractors to use more material to accomplish the same work during the warmer months, therefore, needing to increase the cost per pound charged to the client.
So, there you have it – our costs for concrete lifting and leveling utilizing polyurethane foam.
When you include the pounds of foam required, the size of the project, additional voids, weather and access to the work site, the average cost of lifting and leveling your concrete is between $7.00 and $12.00 per pound of polyurethane foam. It’s important to remember that based on your contractor, location, and age of concrete, these prices will vary.
How Long Does It Take To Do A Concrete Lifting?
Most concrete leveling installations take only a small portion of the day. When using polyurethane the material will be cured by the time the installation crew has finished patching the injection holes and cleaning up. In most cases you’ll have a level, fully functional concrete surface within just a couple of hours
Concrete Lifting Conclusions
Concrete lifting, also known as concrete leveling, mudjacking, or slabjacking, easily lifts sinking concrete to eliminate tripping hazards and cosmetic eye sores. Walkways, sidewalks, driveways, concrete steps, patios, mailboxes and garage floors can all be easily lifted and made level again for less than half the cost of concrete replacement. Concrete lifting saves time and money. It eliminates the need for demolition and disposing of old material, minimizing preparation time, and taking little to no time to clean-up the affected area.
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.