4 Common Causes of Cracks on Concrete

Concrete is a popular building material used across the world — more than any other human-made material. You most likely have concrete structures on your home, be it on the floors, sidewalks, or patios. Concrete cracks and voids are the bane of every homeowner. When you spot cracks, you should seek concrete crack repair services as soon as you can. Here are the common causes of cracks.

1. Excess Water in the Mix When Installing Concrete

Concrete is made from combining cement with sand or gravel, and water. It takes an experienced and expert contractor to strike the right balance of cement, sand, and water when making concrete. When excess water is used in the mix, it leaves cracks and voids on the slab when it eventually evaporates. Experts call it plastic shrinkage cracking. You may spot these cracks a few days after the job is complete.

Mostly, the cracks will start around the re-entrant corners, and where the concrete intersects with objects such as pipes, utility holes, and drains. When you spot these cracks, you should get a repair service before they spread. That’s why you should be very careful when picking a contractor for your concrete works. When concrete is installed correctly, you’ll not worry about crack repairs for the foreseeable future.

2. Thermal Changes

Temperature differences within the concrete or the surroundings can result in cracks. Generally, heat causes it to expand. When this happens, and it does not have enough room to expand, it pushes other structures like brick walls or house pillars that stand in its way. This causes stresses and cracks start emerging with time. Typically, contractors utilize expansion joints that relieve the stress created by the expansion.

Additionally, extreme temperature changes like excess heat in the summer or the chill cold in winter may also trigger cracks. Therefore, during summer, your concrete expands. Come fall, it contracts. With time, the stress impacted on it may exceed the in-place tensile strength. Before long, your concrete begins to crack. However, thermal cracking can be combated by preparing in advance and seeking crack repair services.

3. Overloading the Concrete Slab

You may over-estimate the maximum weight that your concrete can hold because we all know that it is massively strong. However, when you overload it, cracks are bound to appear. This is more common on commercial concrete floors than on residential concrete in your home. But after extended periods of heavy rains, the ground below the concrete may get soft if some of the water penetrates to the underground. Therefore, it will sink when heavy objects like your RV runs on it.

4. External Stress on the Concrete

When you are repairing the immediate area around or within your concrete, it’s possible to interfere with the structural integrity of the concrete and cause cracks. For instance, you may be doing plumbing repairs and have to access a pipe that overlaps with the concrete. During the repair process, you may interfere with the concrete and cause some cracks around the corners. If you don’t get the cracks repaired, they’ll soon spread to the rest of the concrete floor. When you have any repairs or renovations in your home that touch the concrete, it’s wise to seek concrete services to repair any damage that may have been imparted on your concrete.

You must engage a reputable contractor for your construction projects. Professional installation will not only yield floors that are appealing but also long-lasting works. Nonetheless, cracks may still invade the floor even then. This is not a reason to panic, as you can engage crack repair services to fix any cracks and voids. There are many methods of crack repair which include void filling, joint caulking, epoxy injection (exterior), or polyurethane injection (interior).

The mistake that most homeowners make is trying to DIY crack repair. Instead, you should trust an experienced contractor near you for professional crack repair services.

How To Prevent Concrete Voids

fill concrete voids

Voids within concrete floors can ruin the look of a floor, looking like air bubbles or pinholes are there. It’s important to take the necessary steps to prevent this from happening, as it negatively affects the aesthetic of the floor. There are steps that can be taken to prevent these voids, so it is never necessary to fill concrete voids.

Acknowledge Change in Concrete Mix Design

Concrete voids are caused when there is air trapped inside the concrete during the curing process. Any changes made to the concrete mix can have an impact on the viscosity. It’s important to be aware of these changes to make that the correct viscosity is available during the application process. By having the correct viscosity, this will greatly reduce the chance of air being trapped during the curing process.

Increasing Time Mixing Concrete Mold

By increasing the mixing times, this helps break up any bubbles formed and prevent excess air from forming within the concrete. With the mixing time being extended, this allows for the air and water within the mixture to break up. The final result will make the concrete mix more consistent than it would be with less mixing time. All of these actions decrease the chance of needing to fill concrete voids.

Using Vibrations</h3

Vibrations have the ability to deter the possible forming of surface voids. When vibrating the mold, any excess water or air will be pushed to the surface of the concrete mix. This makes vibrations an excellent tool to prevent any surface voids from forming in the concrete, allowing you to save time and money by eliminating the process that would fill concrete voids .

Using Aggregate

By using aggregate that is more uniform, the concrete gains a more fluid texture. With this positive change in the texture, the chances that any air or water will get trapped within the concrete mix decreases greatly. It’s important to use an aggregate that doesn’t have out of order pieces in your concrete mix. Performing this step is a great way to prevent ever having to fill concrete voids, which can be costly.

Use the Correct Method of Concrete Placement

When placing concrete down, this process can easily be the cause of concrete voids forming. It’s very beneficial to correctly place concrete down because doing so will eliminate a large chance of any voids forming. By slowing the placement method down, this can prevent any extra air from being encased in the concrete while the placement method is occurring. If you speed up the placement process this can cause the concrete to separate, which ends up causing more surface voids. Using the correct placement method is a great way to ensure that no surface voids affect the concrete surface.

Use the Right Release Agent

It’s vital to use the correct release agent for the process of removing concrete on the molds that form the concrete. If this isn’t done correctly, puddling can occur in the concrete. Puddling traps any air and water, effectively stopping them from being removed during the vibration process mentioned above. The release agent needs to be applied thinly and accurately for the best possible results. When it is thinly applied, this allows for air to escape the concrete and prevent any air bubbles from forming.

By avoiding concrete voids, this decreases the chance of needing to use a concrete crack filler. The best way to ensure that it won’t be necessary to fill concrete voids is to take these preventative steps beforehand. That way, the concrete will be placed and have the best possible quality.

4 Benefits of Concrete Crack Repair Service

concrete crack repair service

Concrete floors make some of the most elegant, durable, and affordable house floors. They are classy, attractive, and resilient under heavy usage. However, concrete cracks are the one thing that steals the thunder from concrete floors. Cracks can be an eyesore on your concrete floor, and you should seek concrete crack repair service to repair them.

Concrete Crack Repair

As soon as you spot a crack on your concrete floor, you should seek concrete crack repair service, and let the experts handle it for you. Cracks are like cancer to your concrete floor, and if you don’t have the cracks repaired, they will soon spread and completely damage your floor. In that case, you’ll have to redo your floors all over again, and this won’t sit well with your wallet. However, professional crack repair will fill concrete voids and revitalize your damaged concrete.

Concrete Services

Once you hire concrete services, the experts will first assess the extent of the cracks before deciding the best method to repair the cracks. If the cracks are uneven and deeply entrenched on the floors, concrete raising is done before any repairs. Concrete raising has been utilized for about 100 years, and it was originally known as slabjacking or mudjacking.

After leveling the cracks, the concrete repair professionals can use a concrete crack filler to fill the concrete voids or choose to repair the cracks. For the most part, concrete crack repair service utilizes polyurethane injection or epoxy injection.

The common mistake that most people make is trying to fix the cracks using crack fillers without first evaluating the extent of the concrete damage. Most of the time, when you apply a quick-fix solution to a concrete crack, you are merely masking the cracks, which will soon reappear and cause more damage to your concrete. That is why you are advised to seek concrete crack repair services to help you repair the cracks.

Here are more benefits of utilizing concrete crack repair service.

1. Prevents Further Damage

This is one of the primary reasons people seek professional concrete crack repair. A small crack on your concrete might look minor, but it may be indicative of a serious structural problem. An expert will take time to scan the entire concrete to establish the root cause of the cracks and repair the cracks appropriately. Resultantly, there will be no further damage to the concrete.

2. Save You Time

It may take you a while to repair all the cracks on your concrete. You may not have the experience to spot the root cause of the cracks. Blindly filling any crack that crops up is counter-intuitive as more cracks will soon pop up. That way, you will never repair the cracks permanently, despite using up more of your time. On the other hand, concrete crack repair service will apply a permanent fix to your cracks in lesser time.

3. Utilizes the Right Tools

Not unless you are a professional concrete crack repairer, you may not have the tools of the trade. Concrete repair utilizes some expensive equipment such as epoxy injection machines, concrete grouting machines, and slab jacking pumps. This equipment helps crack repair companies fix all types of cracks, including plastic shrinkage crack, heaving crack, and expansion cracks.

4. More Convenient and Saves You Money

Why go through all the hassle of trying to repair all the cracks on your concrete or buying or renting crack repair equipment? In the long end, even after all the inconveniences, it will still be expensive to repair the cracks if you don’t have enough expertise. Hiring concrete crack repair service will save you both money and time.

Ultimately, professional concrete crack repair service will fix your concrete damage comprehensively. Cracks on your concrete may indicate serious structural problems with your concrete floors. That is why you should only trust the reputable and experienced concrete crack repair companies to repair the cracks on your concrete.

Top 4 Best Concrete Crack Repair Methods

concrete crack repair

Concrete is a vital construction material extensively used in buildings, roads, bridges, and dams. However, like most commonly used construction materials, concrete may develop cracks over time. This is because crack not repaired can continuously expand until it becomes dangerous enough to cause structural failure. Repairing a cracked concrete is both time and cost-constrained, and as such, adopting the right concrete crack repair method is important so as to significantly save time, money, energy while producing a long-lasting result.

Understanding the type and nature of cracks that have occurred in a building is the first step towards selecting the most effective method of concrete crack repair. Common crack types include horizontal, vertical, diagonal, and step cracks.

A simple concrete crack repair for a small vertical or diagonal crack without signs of distress may involve filling voids with additional concrete to keep moisture out. Otherwise, the following top crack repair methods are usually adopted.

Epoxy Injection

Epoxy injection for concrete crack repair is useful for filling cracks as narrow as 0.002 inches (0.05 mm). The technique here generally involves establishing entry and venting ports at close intervals along the cracks, sealing the crack on exposed surfaces, and subsequently injecting the epoxy under pressure. However, unless the underlying cause of the cracking has been corrected, it will probably recur near the original crack.

The efficiency of epoxy injection is greatly affected by problems such as silt contamination and leakage, both of which need to be fixed for epoxy injection to last. This crack repair method requires someone with the right combination of skills, discipline, and tact for successful execution.

This method is unsuitable if cracks are active and in large numbers, as well as if water leakage cannot be controlled. On exposure to fire and elevated temperature, epoxy resins lose strength significantly and thus may require fireproofing.

Routing and Sealing

Routing and sealing is the simplest and most common concrete crack repair method. The idea here is to treat the crack like a joint. The technique simply involves enlarging the cracks on the surface and then sealing them with a joint sealant. However, it is vital to adopt the right width to depth aspect ratio when sealing the joint so as to leave enough room for movement. This method is unsuitable for structural repair, serving only as a remedy for minor cracks.

Stitching the Crack

Just like the name implies, the crack can be stitched as a form of repair. The procedure involves drilling an entry and exit hole across the cracked surface and running a number of U-shaped metallic staples through the holes, anchoring them firmly in the hole using either an epoxy-based system or grout. This repair method is efficient and long-lasting.

Drilling and Plugging

This method is recommended for its cost and time efficiency. However, it is only suitable for repairing vertical cracks running in straight lines. During this procedure, a series of vertical holes are drilled in the crack and grout is passed down the holes, forming a key. The key prevents leakages and loss of soil from the wall.

Other concrete crack repair method includes gravity filling, dry packing, overlay and surface treatment, etc. Which is best for a specific case is largely the decision of the concrete service expert. If you have questions about concrete crack repair, contact us today.

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.

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.

Will concrete crack when raised?

One of the questions we are asked is “will raising our concrete damage it?” With over a thousand jobs under our belt and thousands of slabs raised the answer is generally no but it is something that is hard to predict. Some of the most gentle lifting on minor settling may generate a crack whereas a huge lift may not. Why?

  1. Concrete of a thickness of less than 5″ is more prone to cracking, unfortunately this includes nearly all the poured slabs out there. Slabs 4″ thick are twice as resistant to fractures (heavy loads from above as well as lifting from below) than are 3″ slabs. The problem is slabs may be 5″ thick in one area and 2 1/2″ in another. Because we can’t know where a thin spot may be we may attempt to lift from the weakest spot on the whole slab which may generate a crack.
  2. Occasionally a slab may bind on something such as a foundation wall or another slab which can cause a crack. Most of the time slabs bound on other slabs are simply cut free of each other which eliminates the problem. Slabs bound against foundations generally can’t be cut free and if stuck cannot be raised without risking cracking.
  3. Finally, there are often cracks that are invisible to the untrained eye already in your slab. These cracks are often in areas that have settled slightly and pinched the crack together or the slab hasn’t been thoroughly cleaned and the cracks are filled with dirt or sand which conceals the fractures. Either way when raised the cracks will open up to some degree when leveled or raised.

In the end the consumer accepts the risk of a cracked slab either when hiring a replacement concrete contractor or someone to raise their concrete. By hiring the most experienced contractor whether replacement or repair you have less chance of a cracked slab when complete. For concrete raising that contractor is Slabjack Geotechnical.

Call today 1-855-752-2522


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Concrete crack and deep concrete crack repair by Slabjack Geotechnical


Concrete crack repair and concrete crack filling are jobs that are often done by DIY’ers but to be done properly and to last several years certain steps need to be taken.

Choosing the proper material is important, whether you choose to use a polyurethane caulk which may adhere better or silicone caulk that is able to stretch further, preparing the concrete to receive the caulk is the most important step for a lasting repair.

If you have grass and weeds growing in your concrete cracks and joints you will want to remove the growth and any dirt that will interfere with the bond between the concrete and the caulk. This may mean pulling the weeds, pressure washing the dirt and debris out of the crack and then waiting sufficient time for it to completely dry. Even in cracks that appear to be clean either vacuuming or blowing out is a step that should be taken to remove dust and debris that will interfere with the concrete bond.

If the crack is deeper than a half an inch you will need to fill the crack with foam rope. Foam rope does two things first it allows the caulk to bind to both sides but not the bottom this aids in the ability of the repair to flex. Secondly the addition of foam rope greatly reduces the amount of material needed for the repair. Most big box home-improvement stores and small mom-and-pop hardware stores will carry one or two sizes of foam rope. Professional caulkers will carry three or four different sizes and have access to many sizes all the way up to three and even four inches in diameter.

The next choice you have to make after the type of caulk is whether you want self-leveling or non-sag caulk. Self-leveling flows into the crack and as the name suggests levels itself out eliminating the need to tool the repair. In contrast non-SAG is placed in the crack and then forced into the crack with caulking spatulas and then tooled to an attractive profile. Most professional Caulker’s prefer non-SAG material, while more difficult to use initially the material itself is more durable, less messy and more consistent.

Generally for concrete crack filling a standard gray, aluminum gray, or sandstone color will closely match concrete whether it be brand-new, a few years old or very old. There are however an entire pallet of colors available for color matching stained or colored concrete.

If you have concrete cracks that you need filled to preserve the look and keep your concrete from settling give the concrete raising and leveling professionals a call today, we fill thousands of linear feet of concrete cracks each year.



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Cracked concrete repair by Slabjack Geotechnical


Repairing cracks in concrete is a question we often get, here’s what you need to know;

Once concrete has cracked it will act as a control joint, in other words it will continue to move, it can be stabilized to a degree but virtually any rigid topping placed over it such as more concrete or tile will crack exactly over the original crack line.

There are several things to consider with cracked concrete, first, is it a heated space? If so movement of the concrete will be greatly reduced due to heating and cooling (expansion and contraction) as a result floor coverings such as hardwood, laminate, linoleum and other semi rigid surfaces will generally be safe to install, you may even get away with some tile but ask your flooring expert which would be “safer” and less resistant to stress cracking.

If it is an exterior slab such as a driveway or sidewalk your best remedy is filling the crack with caulk, these are available in different formulations such as polyurethane, acrylic and silicone each with its own advantages and disadvantages. While we are on the topic, filling control joints is also recommended especially once the joint has broken. Keeping water, weed growth and ant colonies away from cracks and joints is key to keeping concrete stable.  Water moving through cracks, root growth and pests all create issues that caulking will help prevent.

In addition to raising and leveling settled concrete we repair and fill thousands of feet of cracked concrete so if you choose to hire someone to deal with your cracked concrete give us a call and we will take care of you.



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