Facts About Concrete Voids and Concrete Damage

concrete crack repair

Though concrete is a durable and inexpensive material used both inside and outside the home, concrete does not last forever. Cracked, uneven, or sunken concrete can occur for many reasons. In rare cases, damaged concrete results from ice, earthquakes, impacts, or overloading. More commonly, however, voids under the concrete are responsible for damaged concrete. When a void is responsible for concrete damage, concrete crack repair may be ineffective without first filling the void. Here are some facts about concrete damage and the process for repairing it effectively:


Voids are underground areas where soil is less dense and, consequently, able to support less weight than compacted soil. This fact is confusing to some people because the general view is that the ground is stable and should always remain so. However, voids under a concrete slab can be caused by a number of conditions:

  • Water flowing under the concrete slab causing soil erosion
  • Underground water flows dissolving limestone shelves and causing soil to collapse
  • Insufficient soil compaction before construction, exacerbated by the weight of the structure built on top of the uncompacted soil
  • Loss of lateral support due to nearby excavation, mining, or construction activity

The risk of voids can be reduced by properly draining soil around the structure and completely compacting soil before construction. However, some voids are, no pun intended, unavoidable. Voids due to dissolved limestone or subsidence probably cannot be prevented in any event.

Concrete Damage

Concrete is strong under compression forces, but weak under tension forces. Prestressed concrete, which has steel rebar embedded in a concrete slab, was designed to compensate for concrete’s weakness in tension. In tension, the steel bars bear the load so that the concrete does not need to. However, there are limits to the tension forces any concrete slab can bear. When those limits are reached, the concrete will crack necessitating concrete crack repair.

Imagine, for example, a concrete slab that is supported in the middle by compacted soil but has voids under each end. The concrete slab would be balanced like a see-saw, with both ends sagging. At this point, gravity takes over and the concrete slab will eventually reach a more stable position. The slab may pivot and slide laterally into a void, resulting in a raised or sunken concrete slab. Additionally or alternatively, the sagging ends will cause the concrete slab to crack in the middle.

Concrete Repair

Concrete crack repair is not as simple as filling the crack. Anyone who has used DIY concrete crack filler knows that filling the crack will be an ineffective form of crack repair absent filling the void that created the crack in the first place. Merely filling the crack will often fall short as a form of concrete crack repair because the crack will reopen as the concrete continues to sag into the underground voids.

The process used to fill concrete voids has existed for nearly 100 years. The process was formerly referred to as mudjacking or slabjacking because the process is exactly as the name implies – grout (referred to as mud in those days) is injected into the void, where it expands and hardens. Filling the void under a concrete slab with grout accomplishes a few important tasks:

  1. Injecting grout into the void densifies the soil, supporting the concrete slab and filling the void
  2. Grout expands, lifting the concrete slab and straightening it
  3. Grout hardens, preventing further soil collapse

There are a few different forms of grout used to fill voids. The “mud” version of grout is a mixture of water, cement, and a fine aggregate, such as fly ash or sand. The grout is usually looser than concrete, since the goal is to fill all the cracks and crevices in the void. As an aside, concrete and cement are not synonymous; cement holds concrete together but cement also holds grout together.

Another form of grout is polyurethane, a polymer. Polyurethane is delivered as a foam which expands and hardens inside the void. The primary benefit of polyurethane foam over cement grout is that polyurethane foam cures quickly and can be injected even when the soil is moist.

In sum, the most common cause of concrete damage voids under the concrete slab and, consequently, repair of cracked, uneven, or sunken concrete often requires that the voids be filled first.

When To Call For Concrete Crack Repair Services

concrete crack repair

If you’ve got concrete in your home as part of your basement construction, foundation, garage floor, or elsewhere, proper maintenance is a must-have. Without taking care of your home’s concrete, you could potentially end up with cracks. Concrete crack repair services are available if you’ve already noticed some damage in your home or are looking to make home repairs in addition to your concrete. Here are just a few common signs that it might be time to call a professional about concrete crack repair services.

Cracks In Structural Areas

Not all concrete damage and cracks are created equal. While cracks in concrete anywhere can be a problem, the ones to ultimately prioritize are the cracks that could impact structural integrity. Due to concrete’s excellent durability and performance, polished concrete flooring has quickly become a popular alternative to marble, granite, tile and linoleum for many commercial facilities. Cracks in flooring can be serious, but cracks in a foundation or load-bearing wall are issues to address as soon as possible.

Signs Of Water Damage

Depending on the location of the concrete damage, it’s possible that it could be allowing water into your home or place of business. A little bit of water might not necessarily seem like an issue, but water damage can quickly become serious and damage the structure of your home or workplace. If you can trace signs of water damage back to cracks in concrete, call for concrete crack repair services as soon as you’re able.

Preventive Maintenance

Sometimes you might come across a crack in concrete that doesn’t seem terribly serious at the moment. Maybe it’s a small hairline crack in your garage’s floor, or you remember a particular issue that caused the damage. Even if the crack isn’t a structural issue or causing more serious types of damage, it’s still important to get it taken care of quickly. Fixing a crack in concrete sooner can help avoid more expensive damage later on.

Knowing when to call for concrete repair services can help you protect your home or workplace from serious damage. For more information or to schedule concrete repair, contact Slabjack Geotechnical today.

BUSTED: 3 Myths About Concrete Leveling

filling voids in concrete

Concrete is the most-used manmade material in the world. Humans have found a way to incorporate the strong and durable material — which is capable of withstanding 3,000 psi (lbs/square inch) on average — in every area of industry and life. However, that doesn’t mean it’s indestructible; concrete crack repair services are often required to avoid the complete replacement of slabs. Concrete raising (also known as concrete leveling) offers an effective and affordable solution to filling voids in concrete, but there are many myths and misconceptions in circulation regarding the practice. Let’s find out the truth.

MYTH: Concrete Leveling Is Expensive

Most people are familiar with the cost of concrete slab replacement, which is notoriously expensive. However, just as repairing your roof is cheaper than replacing the entire thing, concrete leveling is much more manageable financially. If you’re looking for a way to improve the health and appearance of your concrete driveway or walkway without breaking the bank, concrete leveling is an excellent option.

MYTH: Anyone Can Do It

While there are many home repair projects that you can do yourself, filling voids in concrete via concrete raising is not one of them. Simply watching some Youtube videos and reading an article does not an expert make, and expertise is required for this process. There is specialized equipment involved that takes knowledge and hands-on experience to operate; if you try to tackle this project on your own, you could end up with a slab that looks awkward, lacks integrity, and will continue to degrade regardless.

MYTH: Caulking Is Just as Effective

Caulking works for most indoor cracks and splits, so your logic may tell you that it can be used on concrete just as well. You’d be wrong; the real problem in cracked concrete lies far below, so if you caulk the area that you see, you’re not actually doing anything to fix the root of the issue. Concrete raising involves filling the soil underneath the slab that has shifted and caused the crack to appear; only by going all the way down can you ensure it has been stabilized and restored to its original strength.

If you’ve noticed cracks in your concrete, don’t wait (or try to repair them yourself); call a concrete contractor as soon as possible.

When Is It Time To Consider Cement Raising?

cement raising

Many homes generally have concrete in some part of their structure, whether in the basement, garage, or elsewhere. In fact, it’s used so frequently in construction that concrete is used more than any other manmade material in the world. While concrete is a great choice to use in construction due to its durability and strength, it needs maintenance and repair like any other material used in your home. If you’ve got concrete in your home, here area few signs you might be in need of cement raising or concrete leveling services.

Cracks In The Structure

Whether they’re in the concrete itself or elsewhere in your house, cracks can be a sign that your concrete isn’t entirely level. These tend to show up over time as your home settles following construction, so you might not necessarily notice them right away. Check your exterior walls, around windows and door frames, and in the concrete itself if the concrete is visible. While you can use concrete crack repair services, it may be a temporary fix; you may need cement raising to really solve the problem.

Warping Floors

While floors can naturally settle and adjust over time, serious warping might be a sign that the concrete foundation underneath is cracking or otherwise uneven. A foundation that isn’t level might look perfectly fine, but on further inspection can have slight imperfections that warp your floors.

Walls Or Floors Pulling Away

Sometimes, the cracks that normally occur along window frames or in places where you can otherwise see them end up in locations that are extremely hard to notice. When this happens, they tend to worsen and cause further damage in your home. This sometimes can result in walls, floors, patios, or other structures seeming to pull away from the surrounding walls. These can create serious safety hazards when left unchecked, and you’ll want to look into cement raising to address this as soon as possible.

Damage to the concrete foundation of your home can be a serious issue that puts the overall structural integrity of your home at risk. For more information on cement raising and how it can help prevent damage in your home, contact Slabjack Geotechnical today.

Top 3 Mistakes You Could Be Making When Grinding Concrete

concrete grinding services

Concrete, of all things, is used more than any other man-made material in the world. Which means you should probably know how to take care of it. Surface preparation is a pretty competitive industry. Making sure you’re choosing the right concrete grinding services is vital if you want a quality outcome. Maybe you are experienced and feel confident in your own ability to prepare your garage floor, for example. Either way, here are three common mistakes that you want to avoid whether you’re a professional or not when you get down to the concrete grinding phase in your construction or home improvement projects.


1. Ignoring Scratches


When concrete grinding, you’ll want to keep an eye on the finish that is being produced as you go. If you are seeing faint scratches appearing, you have to remove them as soon as possible. Hoping the little nicks and scratches will go away on their own will only contribute to continued manifestation as you polish your concrete floor. If you start to see scratches after using your first resin, you should never assume that your second step in the process will “fix it”. Basically, do not leave the cracks and hope they go away because, inevitably, they won’t, and as a result, your final product will suffer.


2. Grinding Too Fast


A common mistake that operators make is running the grinder too fast. All commercial concrete grinding services should know not to do this. However, this tends to happen when the operator wants to produce results faster, so they will turn up the speed of the grinder in an effort to get more done in a shorter amount of time. However, the increased speed can overheat and glaze over your diamonds. This happens more often than not on harder concrete. This glazing over prevents them from cutting properly. Of course, finding the right speed is important but speed on its own doesn’t equal better production rates. At the end of the day, greater downward pressure equals faster grinding. A heavier machine will obviously allow for more head pressure. The opposite is true of larger machines where a double segment offers better performance due to the fact that it is grinding a larger space at one time. Concrete floor grinding is a competitive industry as well as being something of an art. Knowing that you’re choosing the best concrete grinding service, or being fully informed when doing it yourself is what is most important for a great outcome.


3. Not Inspecting Beforehand


While it sounds silly and probably seems impossible, you would be surprised how easy it is to look at a surface and assume the process. Especially if you work for professional concrete grinding services. You’ve pretty much seen it all before. However, that is not an excuse to not examine the surface you’re working with before you do anything to it. You need to inspect the floors for anything above grade and cut it off, hand grind it so it’s level, or hammer it to below grade. Address any crack repair you may need, and once you’ve eliminated any and all above grade issues, you can begin grinding it with the concrete, which results in an interesting detail which can add personality to the floor. If you DON’T inspect the floor and address the above grade parts before you start, you will almost surely damage your machine. Concrete floor grinding is probably a task that is best left to the professionals, call local concrete grinding services to get quotes and expert advice.


How to Handle Damaged Concrete

concrete grinding service

As an informed homeowner, it’s important to stay on top of home repaired. Everything from the roof to the foundation should be considered to ensure the safety and comfort of you and your family. If you happen to have damaged concrete, this can lead to several potential problems in the future. But there is good news. A quality concrete grinding service guarantees timely, cost-effective repairs so you can get back to the things that matter.

Several factors contribute to concrete damage. Seasonal changes such as heat, humidity, and moisture can dramatically impact the concrete used in and around your home and garage. Further, the threat of soil erosion can cause major structural issues that, if left unaddressed, can affect everything from doors and windows to tile and flooring. When concrete is damaged, it leads to a fundamental imbalance in your home, which causes off-kilter pressure to be placed upon certain areas of your structure. When you consider the holistic wellbeing of your property, concrete damage ranks high in importance, and repair should never be neglected.

Depending on the state and nature of your concrete installation and damage, different concrete services may be advised. Some of the most common procedures are crack repair, slab jacking, and cement raising. A major advantage to raised concrete is that it can be used immediately, unlike new concrete where you need to wait 2 – 7 days, or traditional mudjacking where you need to wait a minimum of 24 hours. Raised concrete can hasten your workflow whether you’re filling voids in concrete or trying to raise the garage floor. New developments in concrete grinding service have a wide range of applications and advantages when compared to the industry’s more traditional, outdated methods.

Handling your concrete problems sooner is always better than waiting for things to get worse. It’s wise to stay informed on industry practices as well as keeping a detailed expense budget so that you’re never surprised by the costs associated with concrete repair. By staying on top of repairs and hiring a credible concrete service, you give yourself the security of knowing that the work is done right to save you money down the road, and keep your home in its best condition.

FAQ About Concrete Raising

concrete services

Concrete or cement raising (also known as slab jacking) offers a cost-effective solution to damaged concrete surfaces. Although the practice has been around for nearly 100 years, many people don’t know very much about these concrete services. Let’s take a look at some of the most frequently asked questions regarding concrete raising.

How much does concrete raising cost?


Concrete raising is usually about half the cost of concrete replacement. At the end of the day, however, the cost of the process is a direct reflection of much leveling material the project will require; generally speaking, slab jacking can cost between two and five dollars per square foot. You’ll need to contact your local concrete company to find out their specific rates, but either way, you’ll be saving money by opting for raising over replacement.

What kind of material is used to raise concrete?


Polyurethane foam (in liquid form) is injected under the damaged concrete. It solidifies into a rigid foam as it raises the slab back into position; this material does not lose its density or shrink in any way, so you won’t need to worry about future issues. As a more advanced form of the traditional mudjacking material, less holes are required to use it, and the holes are smaller so the repair is virtually invisible.

How are the holes sealed?


After the concrete has been raised via mudjacking, a foam plug is inserted into the hole and then patched over with cement. The foam plugs act as shock absorbers when slabs are affected by seasonal frost. For concrete raising that uses polyurethane foam, these plugs are not required because the foam performs both functions. Although the final product will be ready for use immediately, it’s recommended to allow the patch material to set first.

What concrete can be raised?


As one of the most beneficial concrete services, any cracked concrete slabs are able to take advantage of concrete raising. However, there is a limit; slabs that are horribly cracked may be too damaged to lift. Your local concrete contractor will be able to let you know the status of your repair and whether or now it can be performed.

If you’ve got a concrete driveway or garage floor, cracks are bound to emerge. Eliminate them immediately with slab jacking concrete services.

How To Repair and Care for Your Concrete Floors

fill concrete voids

Concrete’s performance and affordable price point have led it to replace traditional flooring materials such as marble, granite, tile, and linoleum over the years.

The types of concrete flooring available for your home

There are three types of stylish concrete flooring available for your home:

  • Plain concrete
  • Stained concrete
  • Polished concrete

Concrete flooring is as functional as it is stunning

What are some other upsides of polished concrete flooring?

Concrete is incredibly durable. In fact, its average strength is about 3000 psi, meaning it can withstand more than a ton of pressure!

Pet stratches and even the pointiest of high heels are no match for this tough substance.

But enough about the perks. If you already have concrete floors installed, or are seriously thinking about it, continue reading to learn how to care for and repair them.


Concrete floors a low maintenance, so they’re perfect for the minimalistic homeowner. The first thing you want to do is opt for a sealer to help prolong the life of your concrete floor. When choosing a sealer keep in mind that there are many options to chose from. A water based sealer is non-toxic and perfect if you live with pets or small children.

Other sealers that each offer their own can add a beautiful shine to your floors include:

  • Acrylics — come in water-based formulas and a variety of different finishes
  • Epoxies
  • Polyurthanes
  • Siliconates — offer a matte finish

When it comes to cleaning your floors, the process is simple. Use a microfiber cloth when mopping and make sure to use a ph-neutral based cleaner. Avoid chemicals such as bleach and ammonia as they are too harsh and can damage your floors.

The issues and what to look out for

Though concrete is sturdy, air or water can cause small holes to appear on the surface. These are called voids or bugholes.

So now you’re probably wondering how you can fill concrete voids. They can be easily smoothed out and you only need a few things and some extra time on your hands to do the job.

How to fill concrete voids

Filling voids in concrete doesn’t have to be a difficult process.

  1. First, you’ll need to drill four holes around the indented area. The holes should be about one inch in diameter.
  2. Once you have done this, connect a slabjacking pump and hose, made to fill reparative material under the concrete slab.
  3. Next, combine one part cement to one part fly ash with two parts clean sand and mix with an expander additive. Add water until the mixture has a grout-like consistency.
  4. Set the slabjacking pup to 10psi after feeding the mixture into the machine and pump the material through the hose.
  5. Fill the void evenly and allow it to dry.

Concrete crack repair follows a slightly similar process if you’re looking to fix an unsightly crack instead. But when dealing with holes, that’s how you fill concrete voids a few steps. If you’re still struggling, don’t be afraid to call in a professional.

The takeaway

Concrete floors can compliment your home beautifully. Especially if you know how to care for them and understand how to fill concrete voids. There’s no reason they shouldn’t last you for years to come.

Fixing Concrete Voids Before They Cause Massive Damage

raise the garage floor

Perhaps you are looking to raise the garage floor. Or maybe you just suspect that there is trouble around the corner with your concrete driveway. Regardless what type of concrete raising or concrete service you are looking to perform, it is important to know how to recognize when you have a potential void in your concrete that would require filling.

What is a Concrete Void?

The first thing to understand is that voids in concrete are not visible. Unlike traditional crack repair (which is very visible), a void in the concrete can build up over time, eventually causing massive damage to the surface of the concrete, requiring large repairs. One of the reasons voids are not detectable by surface damage at first is that concrete is very strong. Average concrete can withstand about 3000 psi (pounds per square inch), and some concrete has a strength of over 20,000 psi. Because of this, the concrete will withstand enormous amounts of pressure and stress, until eventually the entire slab just cracks. When it does crack, the crack is usually massive.

The most high-tech solution is to use a GPR, or ground penetrating radar. GPRs are used by contractors to detect voids or holes under a concrete slab. If you are looking to raise the garage floor, it could be because you have a void in your concrete. Garage floor voids are difficult to detect without a GPR. Without a GPR, you might be able to detect a void by driving into your garage and listening to see if you can hear a shallow or hollow sound as you drive over the concrete. Sometimes there will also be tiny cracks throughout the concrete, or sometimes you will be able to detect a shift or tremor in the concrete. All of these are signs that you should look to raise the garage floor and fill the void.

How to Fill Concrete Voids

Filling concrete voids can be tricky. Because the void typically isn’t accessible through a visible crack (yet), there are only a couple of options. For small slabs, such as a sidewalk, it is possible to pack under the slab with gravel or some other material to keep the void from damaging the concrete. For larger slabs, such as a patio or garage, this isn’t usually an option.

One of the best methods for large slabs is to use some sort of expanding polymer substance, such as Polyurethane. Polyurethane can travel several feet through openings on the side of your slab to find and fill the voids underneath. This can sometimes be enough to prevent any further damage to the slab, even if you are looking to raise the garage floor.

When to Hire a Professional

Concrete can be expensive, and so is fixing it. Sometimes, because of the nature of a slab (especially in a garage), it can be difficult to access places where you can easily fill a void using Polyurethane or another expanding substance. Even if you want to raise the garage floor, you will need to fill the voids underneath in order to ensure good concrete strength and durability. There are plenty of options for slab jacking and soil cement stabilization that can be done professionally to ensure that your concrete is secure and solid for years to come.

Before you sell – Fix the foundation, before the inspector fixes your pocket book!

pressure grouting contractors

Are you getting ready to put your home on the market, but worried about what they might find during the foundation inspection? Potential home buyers want to make sure that they are buying a property that is built on a strong and lasting foundation. If you know that your foundation has structural or cosmetic damage, now is the time to take action and hire pressure grouting contractors.

Pressure grouting contractors can maintain or improve your home’s value by repairing foundation issues that are small or large. Pressure grouting is a shoring method that fills, solidifies and lifts target areas in the soil beneath your home.

This concrete raising process improves the load bearing capacity of your foundation. It will lift up and level out any uneven or sunken concrete slabs. The soil cement stabilization process protects your foundation against future problems from shifting or moving earth.

Concrete raising is not a new process. Originally called slabjacking, this minimally evasive technique has been used for almost 100 years. In addition to leveling your foundation. it can be used to fill concrete voids in driveways, for crack repair and to raise the garage floor.

Pressure grouting is very versatile. It can be used for new construction as well as existing construction. It can be used to fix an existing problem or to prevent a future problem. Concrete professionals consider pressure grouting as a very cost effective measure.

The reason you are experiencing foundation issues, may have nothing to do with the home itself or previous maintenance. There are certain geographic regions that are known to have softer, more loosely packed soils. When soil structures are weak, the earth can shift and cause structural problems.

There are many reputable and experienced pressure grouting contractors available to help you. These concrete service professionals will visit your home, complete their own detailed inspection, and then recommend the right repairs for your unique problems.

When you put your home on the market you can show buyers a copy of your work order to prove that you resolved any existing issues. This will give potential home buyers piece of mind.

Take action today!

If you suspect that your home has foundation problems and you are about to put the home on the market, take action and schedule a foundation inspection right away. Potential home buyers want to make sure that they are buying a property that is built on a strong and lasting foundation.