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Concrete Pitting, Flaking & Staining

Concrete pitting, flaking, and staining can occur anywhere there is concrete. What is it, and what are the warning signs to watch out for?

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Most homeowners have concrete somewhere on their property. Whether it’s their foundation, patio, driveway, steps, or even their floors, concrete has a place because it’s cheap, durable, and long-lived. However, there are some issues that come along with concrete, especially over the years. In particular, the main issues can be pitting, flaking, and staining. 

What leads to this? How can it be fixed? And most importantly, how can you spot the problem signs before it gets out of hand? Let’s explore all that and more, so you can learn how to keep your concrete in peak condition with the help of Ohio Basement Systems. 

What Is Concrete Pitting, Flaking, and Staining? 

Concrete pitting refers to the formation of small holes in the concrete. These small holes are called pits. This phenomenon can be quite common if you live in Cleveland or Toledo, Ohio, since the primary cause of concrete pitting is the repeated freezing and thawing of water inside the concrete. Since both Cleveland and Toledo experience an average of low 30 degrees Fahrenheit weather during the winters, concrete is very vulnerable to forming pits. 

Concrete flaking is also known as “spalling”. This occurs when any small flakes of concrete break off a larger body of concrete. 

Concrete staining is when the concrete becomes stained with a substance, usually something liquid or chemical. Although it may not look like it, concrete is a very porous material. Any substance it can absorb has the potential to stain your concrete. 

Problem Signs of Concrete Pitting, Flaking, and Staining 

cracks

Many of the problem signs of these concrete issues overlap each other. In fact, you may also find that one of these concrete problems is a warning sign for another. This makes it easier to watch out for concrete pitting, flaking, and staining all at once. 

  • Pop-outs or Leaks  

“Pop-outs” refer to a spot in the concrete where the top of the concrete has separated, creating what looks like a hole. You may find water leaking from these pop-out holes, too. However, these “leaks” are usually dry. Instead of spreading water, they can let other substances leak through, which commonly form concrete stains. 

Pop-outs usually happen in sections with high iron and coal concentrations within the concrete. Exoerts call these “soft stones” because they can absorb more water compared to many other stones. This water absorption can soften the concrete and cause the top layer to pop out.   

Not all pop-outs are accompanied by dry leaks, but many of them are. If you find an area of your concrete that has a pop-out, this is an early sign of concrete staining. Anything that leaks from these concrete holes may potentially stain your concrete. 

  • Discoloration or Immovable Stains 

Any form of discoloration or stains that cannot be easily washed away with water is a very prominent sign of concrete staining. Likewise, any stains on the concrete that cannot be washed off with water are a very likely sign a substance has made its way into your concrete’s pores. At this point, the concrete sets, resulting in immovable staining. 

  • Cracks  

One of the earliest warning signs of concrete flaking is cracks. Cracks can be indicative of structural shifts within the concrete. Concrete flaking is often a result of shifting within concrete slabs; therefore, if you find any cracks, you may be dealing with concrete flaking. 

Using cracks as a problem sign of concrete flaking can be tricky, however. Although it is, indeed, a warning sign, cracks can result from many other issues as well. If concrete cracks are accompanied by other areas of chipped concrete, this is more evidence that you have concrete flaking problems rather than another structural issue. 

  • Chipped and/or Coarse Concrete 

If you find any concrete that looks chipped or that there are small portions of concrete missing, you may have concrete flaking on your hands. Any concrete area that has become coarse or rockier than before is a more subtle sign of concrete flaking. This is because when pieces flake off, it exposes the rough, rocky underlayer of your concrete. If you are confident that the texture of your concrete was smoother in the past, there is a high likelihood the concrete has flaked off.  

  • Concrete Pitting 

Once you notice some signs of pits in your concrete, you want to start seeking out viable solutions. Please note that most of these holes can be very small—as small as the tip of a pencil lead even—so you may want to look and inspect your concrete very closely. 

Concrete pitting is, however, a problem sign of concrete flaking and staining. This is because concrete flaking is more likely to occur if the concrete is exposed to the elements. Since concrete pits allow substances to enter more readily, there is a possibility that such substances can shift the concrete structure around. This structural shifting can result in concrete flaking. 

Similarly, the pits help concrete beds absorb substances quicker. If any staining substance becomes absorbed by this pitted concrete, concrete staining is very likely to happen. 

Keep in mind that substances that can enter concrete pits vary in composition. They can be almost anything—anything solid, such as debris, or anything liquid, such as rain, snow, or any form of chemicals that you may own. As such, the increased (or decreased) chances of concrete flaking and stains will also vary. 

What Causes Concrete Pitting, Flaking, and Staining? 

Now that you have identified if you have concrete pitting, flaking, or staining, you can understand what causes these problems in the first place. 

  • Freeze-Thaw Cycles of Water  

If water is repeatedly frozen and thawed in concrete, it can cause both concrete pitting and flaking. Because concrete is a very porous material, it readily absorbs any water that lands on the surface. This is not usually problematic until this water undergoes continuous freeze-thaw cycles. 

During the frigid winters of Ohio, snow can pile on your concrete and cause any excess water to freeze. Frozen water can expand up to nine percent larger than liquid water. When water that has been absorbed inside the concrete freezes, it also expands the pores of the concrete. Once this water thaws, the concrete pore has become permanently enlarged. This invites more water to enter the concrete pore, and the cycle continues with the seasons again and again. 

These repetitive freeze-thaw cycles place a lot of pressure on your concrete, resulting in concrete pitting and, in more extreme cases, concrete flaking. This is because the concrete is prone to changing shape and breakage due to the continuous stress and movement caused by freeze-thaw cycles.  

  • Excessive Salting 

Salting your concrete may be a natural thing to do, especially when you need to remove the ice and snow to walk or drive. Unfortunately, salting may be the root cause of why your concrete is flaking or pitting.   

Salting concrete is a solution for melting snow and ice when needed. However, using salt can invite more water to enter your concrete, making pitting and flaking possible. Salt can melt ice by lowering the freezing point of the water in the snow. After some time, the salt reduces the snow to liquid water. This liquid water can then enter your concrete with ease. 

Of course, the salt will not remain in the snow forever. Once the salt depletes, the liquid water is now prone to freezing again if the temperatures are right. Because this water has already been absorbed inside the concrete, once it freezes, the freeze-thaw cycles can apply a lot of pressure on the surrounding concrete and to the upper layers, resulting in concrete pits and/or flaking. 

  • Poor Concrete Placement  

Unfortunately, while this is rare, sometimes contractors make mistakes when pouring and curing the concrete for your house. Concrete that has not been mixed properly for your location and climate, or that hasn’t been cured correctly, is vulnerable to concrete damage later along the line. 

Concrete that has not been mixed properly is more likely to crack and break and thus more likely to flake off. This happens because mixing the ingredients contributes to its durability and strength. Because the ingredients in the concrete are not easy to blend, proper mixing for strong concrete requires patience. 

Curing refers to the process of providing the appropriate moisture and temperature conditions for the concrete to dry. Curing is also important for concrete stability and structural integrity. Improper curing results in weak concrete due to the unstable environment it endures while drying, therefore increasing the likelihood of breakage and pit formation.  

  • Rebar Rusting or Corrosion 

The rebar, also known as reinforcing bar, is the steel bar that provides stability for your concrete against tension. This rebar runs alongside the concrete so that it can improve its durability. 

Despite it being underground, the rebar is not impervious to rusting and corrosion. The presence of water and oxygen in the concrete are the main culprits behind rusting. Once both elements are introduced to the rebar underneath the concrete surface, they can chemically react with the steel material of the rebar, resulting in rust. 

Rebar corrosion is caused by the intrusion of chloride ions. Chloride ions are commonly found in deicing salts. 

Rebar rust can accumulate and occupy more space underneath the concrete, resulting in concrete shifting and, ultimately, flaking. Corrosion of the rebar can destabilize the structural integrity of the concrete it is meant to support, also leading to the flaking of concrete. 

  • Exposure to Minerals or Chemicals  

Concrete staining is often a result of spills. Oil from cars can easily be absorbed by your concrete due to its porous nature and trickle into the deeper layers, leaving a hard-to-remove stain. 

Minerals from rust pop-outs or fertilizers can also cause staining. Remember that pop-outs are caused by iron and coal within the concrete that “pop” after absorbing an excessive amount of water. When these iron and coal deposits encounter water and air, rust can form. This rust formation can stain your concrete.  

Fertilizers contain a bounty of minerals that can change color and stain concrete when it reacts with air and water. Some examples of these minerals are iron, magnesium, copper, and zinc. 

How Can I Fix Concrete Pitting, Flaking, and Staining? 

concrete lifting

Solving concrete pitting, flaking, and staining is not always easy. Fortunately, there are a number of solutions that Ohio Basement Systems offers to the Cleveland and Toledo area that can help to resolve these issues for good. 

  • PolyRenewal™ Injection Foam  

The PolyRenewal™ Injection Foam is an innovative polyurethane foam that can repair concrete pitting, flaking, and staining. PolyRenewal™ cures in 15 minutes, which lowers the risk of improper curing, helping to work against the formation of pits and flaking in the future. Because the foam has expansive properties, it will fill in any pits within your concrete and can repair pieces of flaked concrete easily and cleanly. 

The PolyRenewal™ foam is also waterproof. This can be very beneficial for preventing concrete staining because it inhibits the absorption of liquid substances into the concrete. 

  • Basement Waterproofing System  

Concrete doesn’t just happen outside. If you are experiencing any pitting, flaking, or stains in your basement, for instance, Ohio Basement Systems has a variety of solutions within our basement waterproofing system

Many basements are built with concrete walls, floors, or both. Ohio Basement Systems offers crack repairs for your concrete walls or floors using an impermeable and flexible sealant that also works preventively so that you do not experience future concrete breakage—whether it is in the form of pitting or flaking.   

Concrete Pitting, Flaking, and Staining

FAQs

Luckily, there are a few measures that you can take to avoid concrete pitting, flaking, and staining. These can be performed at home easily, with minimal cost on your part. 

  • Preventing Concrete Pitting, Flaking, and Staining  

De-icing your concrete with salt can help melt any snow or ice, but it can do a lot of damage to your concrete over time. To avoid that problem, it is best to avoid using salt when you want to melt the snow off your concrete. You can instead look for other alternatives. For stains, be sure to perform messy jobs, such as oil changes, away from your concrete. If using fertilizer, take extra precautions to not get any onto your concrete paths or driveway to prevent staining due to chemicals. 

Of course, understanding what causes the formation of concrete pits, flakes, and stains helps when working to avoid it. Because the main culprit behind concrete pitting, flaking, and staining is water (both liquid and frozen), inhibiting water absorption can go a long way. The most versatile prevention method is to protect your concrete holistically.    

  • Protecting Your Concrete  

Concrete sealants, when applied to concrete, fill in or block the concrete pores. This prevents water, salt, or other liquids from being absorbed. It protects against concrete pitting, flaking, and staining because it inhibits the penetration of most substances into the concrete. Many are made of silicon, a very water-repellent material. 

While concrete sealants can certainly work against future concrete pits, flakes, and stains, they are not permanent. Depending on the type of sealant, they last between one to five years, sometimes five or more years, before needing to be reapplied. Additionally, some sealants do not fill the pores of your concrete—they simply block it. The PolyRenewal™ Foam offered by Ohio Basement Systems is more permanent because, while it is waterproof like many concrete sealants, it cannot be washed away and is not affected by freeze-thaw cycles. Due to its versatility, it can also prevent other concrete-related issues on top of concrete pits, flakes, and stains. 

When in doubt, you should not work with any chemical-based material on your concrete if you want to avoid staining or the absorption of liquids. The following are some general guidelines of what substances to avoid if you want to maintain your concrete. 

  • Ammonium Nitrate and Sulfate  

Ammonium nitrates and ammonium sulfates can chemically react with your concrete. These reactions may cause damage by disintegrating the concrete, leaving it vulnerable to pit formation and flaking. As such, these open pores and flaked concrete will absorb substances more readily and therefore result in an increased likelihood of staining. 

These chemicals are often found in many de-icing salts and even some fertilizers. Never use a de-icing salt that has either of these chemicals, because they damage your concrete in no time at all. Ammonium nitrates and sulfates in fertilizers do less damage upon contact, but only if you remove the fertilizer off your concrete as soon as possible. If remnants are left on your concrete, they will absorb into it over time, resulting in fertilizer staining.  

  • Hydrocarbons, Cleaners, Solvents 

Hydrocarbons, cleaners, and solvents readily penetrate your concrete’s pores, resulting in stains. This is due to the chemical composition of these substances. When these chemicals land on your concrete, they decompose. The decomposition of these chemicals produces molecules that can eat away at your concrete, leading to stains. 

Some examples of hydrocarbon substances include oil and grease. Cleaners and solvents may include items such as bleach or paint.

There are a few alternatives to de-icing salts that you can use if you wish to melt ice and snow. 

  • Calcium Chloride Salts  

Most de-icing salts are made of ammonium nitrates or sulfates, which cause concrete damage. There are, however, some de-icing salts made of calcium chloride, a much safer alternative. 

Compared to typical salts, calcium chloride has a much lower freezing temperature. This consequently prevents freeze-thaw cycles from recurring because the calcium chloride is less likely to refreeze once it has been absorbed in your concrete. This can prevent concrete pores from being enlarged and concrete form being shifted, ultimately thwarting concrete pitting and flaking. 

  • Magnesium Chloride, Potassium Chloride, Sand  

Much like calcium chloride, magnesium and potassium chloride can be used as a safe de-icing alternative. Calcium chloride salts, however, have the lowest freezing point (-25 degrees Fahrenheit), which is why it is most recommended, especially if you want to avoid any chances of refreezing in your concrete. Sand can also be used, but it only serves to provide traction and does not melt ice. 

However, keep in mind that these are not preventative measures against concrete pitting and flaking. If you wish to avoid the possibility of concrete pitting or flaking from any form of de-icing salts, you should consider Ohio Basement Systems’ PolyRenewal™ Foam for outdoor use. Even if you were to use traditional de-icing salts, the PolyRenewal™ Foam is able to withstand absorption of excess water and salts, so you do not have to worry about your concrete forming pits or flaking off. If you have ice problems in your basement (which can happen in the winter), Ohio Basement Systems also offers waterproof walls and floors that inhibit water absorption and can also come with insulation that prevents future freezing.

Seek Out the Experts 

Concrete pitting, flaking, and staining can really make your home look more worn down than it is. It is not always easy to prevent this from happening to your concrete, especially with the weather in Ohio and other things out of your control. By getting in contact with Ohio Basement Systems, you can begin to reverse the damage and prevent future damage. Contact us to schedule your free inspection and receive a no-obligation quote on any work needed.  

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SERVING CLEVELAND, YOUNGSTOWN & NORTHERN OHIO

OHIO BASEMENT SYSTEMS

7950 Bavaria Rd.
Twinsburg, OH 44087
(330) 235-1229