Poured concrete is one of the most used building materials in the world today, and it is to the credit of this material that such a relatively low percentage of buildings experience any issues. When concrete becomes damaged or unstable, it is generally because of a fundamental flaw in the construction process or because of prolonged exposure to unhealthy environmental factors or pressures. Learning to spot and decipher the warning signs of damaged concrete will be of real benefit to any homeowner who wants to avoid unnecessary repair bills.
The Strengths and Weaknesses of Concrete
Concrete is one of the most popular construction materials for a reason; its benefits outweigh its weaknesses heavily in most situations. Knowing what the limits of concrete are may seem unnecessary for those who are not involved in construction, but it can be helpful for homeowners. Knowing the weaknesses of the materials used in making your home will help you to prevent and predict issues.
- Not susceptible to age-related deterioration
- Resistant to high temperatures
- Resistant to wind and water
- Easy to mold
- Relatively low tensile strength
- Less ductile
- Very heavy
- May contain soluble salts (can cause efflorescence)
One of the biggest contradictions of concrete is the way in which it is both resistant to water damage and susceptible to damage from prolonged dampness and seepage. All it takes is the right set of conditions.
What Can Cause Concrete Pitting, Flaking, and Staining?
Some kinds of concrete damage, like spreading cracks and sagging, are well understood. This is because they tend to be caused by serious, structural issues within a home. Most homeowners are aware of the signs of foundation damage, for example, as a matter of necessity. The causes of cosmetic issues like pitting, flaking, crazing, spalling, and staining are generally less widely discussed, possibly because they are cosmetic in nature (most of the time). What many homeowners do not realize, however, is that these issues can also show up as, or turn into, a part of a deeper and more dangerous set of issues.
The most common causes of this kind of damage are:
- Improper Mixing
Mixing concrete is a very changeable process that can be tailored to the needs of a specific project. This is one of the things that make concrete such a widely useful substance for construction. However, it can also lead to issues when the person mixing the concrete makes a miscalculation. Adding too much water to a mix, for example, can make it more prone to pitting, flaking, and scaling. Scaling, for those who don’t know, is a less severe version of spalling, in which the damage is almost exclusively cosmetic in nature.
Likewise, adding aggregate that is too loose or even sandy to a concrete mix can make it weaker and even cause it to crack and crumble under pressure. Finally, there are some minerals that, when added to a concrete mix, do not affect the performance of the surface, but make it more prone to staining and discoloration.
- Substandard Construction Methods
As well as issues with the concrete mix itself, improper practices during construction can leave flaws in concrete surfaces that later manifest as spalling, scaling, pitting, or even serious levels of cracking. Good examples of this are a substandard curing process, a lack of curing, or even over-curing.
Another example of how the method of laying concrete can cause damage is the use of hard troweling. Hard troweling is a process of vigorously troweling the concrete surface after it has been laid to compact it after it has become too hard to trowel. The key issue here, of course, is the disturbance of the surface after it has started to set. This can result in an improper water-cement ratio in certain areas. This will lead to discoloration, but can also lead to more serious issues by causing an inconsistent density across the surface area.
- Freeze/Thaw Cycles
Repeated snap freezes and thaws are incredibly damaging to most substances, and concrete is no different. If your concrete is properly mixed and has been laid in line with industry standards, snap freezes and thaws should not affect its structural integrity and strength, but they may result in cosmetic damage. Pitting, flaking, bubbling, scaling, and even spalling are common in concrete floors and walls that are exposed to repeated freezes and thaws.
Extreme cold is, of course, not overly common across Missouri, but the conditions don’t need to be arctic in nature to cause this kind of damage. You should check concrete structures after heavy snows or sudden storms, for example, to catch the signs of damage early.
- Persistent Leaks
When it comes to stained concrete, persistent leaks from either inside or outside the property are the usual culprit. Leaking basement window wells, for example, can cause large, unsightly stains to spread over the walls and floors underneath them (depending on the severity of the leak in question). Likewise, a leaking water heater or washing machine that is sitting on a concrete floor can stain the concrete even if the leak is minor.
Finally, leaks in your interior plumbing system can cause stains and even minor cosmetic damage to your property’s concrete surfaces if left unchecked for a prolonged period of time.
- Persistent Seepage
Seepage is a process by which water seeps through porous concrete and into a property. This can happen in any property with poured concrete foundation walls and flooring. It doesn’t necessarily require any damage to be present. Likewise, seepage will not always cause damage (caused by general dampness), but it can result in bubbling, flaking, and minor scaling if it is persistent and the concrete is already a little weak.
These are just some of the causes of concrete pitting, staining, and scaling, but they are the most common and damaging. It’s important to remember, however, that this kind of damage to your property’s concrete surfaces is also a problem sign for other issues.
What Concrete Damage Can Signify for Your Home
Spalled, damaged, or flaking concrete is a problem sign that you should not ignore. Despite being cosmetic in many instances, these issues can also be tied to more serious structural issues within your property. This is, of course, the case for many seemingly harmless things; damage to a property is almost always more complicated than it first appears. So, if you see spalling, scaling, pitting, flaking, or staining in your concrete walls or floors, the underlying issues that are most likely to be at work are:
- Excessive Hydrostatic Pressure
All properties are subject to some level of hydrostatic pressure (which is caused by the weight of water in the soil around a home). In fact, they are designed to withstand it, but it is possible for this pressure to become unbearable. When this happens, it is very likely that the structure of a home will suffer. One way this can happen is via a gradual buckling or bowing of the walls. This bend inward is worrying for a number of reasons and can cause collapse.
A broken, flaking, pitted, or spalling surface can be a visible sign of the early stages of this issue, especially if the surface is crazed (covered in a web of shallow, hairline cracks). If this is the case, you will notice that the damage is more focused towards the middle, top, or bottom of the wall, depending on where the deviation is most pronounced. Over time, this will develop into larger cracks and a noticeable bulge or lean.
- Weak or Unstable Soil
Weak or unstable soil can cause many different problems for your property, but the most obvious issues are those that start in the foundation. Foundation problems like subsidence and settlement are very serious and will require immediate professional intervention. When advanced they are likely to cause:
- Sticking windows and doors
- Deep, spreading cracks
- Uneven flooring
- General dampness and humidity
However, in the earliest stages, the pressure caused by the shifting process and the persistent dampness can combine. They will then lead to cosmetic deterioration in the concrete that is being affected. This is not hugely common, but it can happen. If you see excessive spalling, flaking, and spreading cracks in your basement floor, it is best to call a professional.
- Lack of Waterproofing
One of the most common causes of cosmetic, surface-level deterioration in concrete surfaces is repetitive freezing and thawing. If your property is otherwise healthy, but you have not invested in basement waterproofing systems, this cosmetic damage can be one of the main results. This is partly because of the moisture in the area and partly because of the fluctuations in temperature.
Basement waterproofing processes do not just address things like flooding and seepage, but also address the climate as a whole within the basement (and your home). Simply installing a vapor barrier and insulation could prevent flaking, pitting, and staining by regulating the humidity in your basement. They could also prevent the serious temperature fluctuations required for rapid freezing and thawing.
These underlying causes can also present themselves in a number of other ways. Other problem signs to be aware of include, but are not limited to:
- Increased energy usage
- Mold formation
- Pest infestation
- Sagging floor
Catching these early signs of damage will ensure that you can act before the problems snowball.
If you have bare concrete in your basement or garage, or even outside, and you have started to notice stains appearing from seemingly nowhere, it is normal to be concerned. After all, these stains are unsightly and can be symptoms of unseen damage in your home. Broadly speaking, there are two main causes of concrete staining:
Defects in the Mix
If concrete is to perform to its full potential, it must be mixed properly and to the right proportions. If the mix is measured or applied in a wildly inappropriate manner it can quickly break down and crumble. This is highly uncommon, however, as there are many safety checks in place in the construction process these days. A minor imbalance, however, can cause concrete to deteriorate in a superficial or cosmetic way over time.
Staining, pitting, flaking, crazing, and bubbling are good examples of this kind of cosmetic damage. These issues can be caused by an improper water-to-cement ratio at the surface levels, inadequate or inappropriate curing, and cement alkalis, among other things. In many cases, purely cosmetic staining can be removed with a power washer or chemical cleaning mix, but it is likely to reoccur over time.
If the concrete in your home was properly mixed, laid, and cured but is still starting to stain, it is likely a result of damage or adverse environmental conditions. In these cases, the staining is likely to remain localized to one area, or certain areas. Meanwhile, staining as a result of defects tends to span the whole surface in varying levels of severity.
The environmental factors that are most likely to cause concrete damage are dampness and pressure. If your basement is incredibly damp, for example, you are more likely to see surface-level staining, pitting, and bubbling in the concrete. However, if pressure is the cause of the damage—for example, pressure from foundation subsidence—you are far more likely to see cracks forming. Of course, this can cause dampness and stains too.
Spalling concrete that has started to peel, flake, or crumble at the surface level is incredibly unattractive. As well as being unsightly, however, it can be a source of issues within your home. As such, you should address it quickly.
Spalling may seem harmless at first, but it can actually result in more serious issues quite quickly. First and foremost, concrete that has become pitted or damaged to a severe extent can form a tripping or falling hazard for anyone in the room. Taking a spill onto a hard concrete floor is no one’s idea of a good time, and it can quite easily result in broken bones and serious injuries.
Furthermore, spalled concrete can create an unhealthy environment by increasing the amount of dust and debris that is washing into your sump pump, gathering in your drains, and even lingering in the air. As well as potentially causing appliance breakdown or drainage clogs, this can exacerbate any pre-existing respiratory issues you may have.
Spalling is a progressive issue that will only get worse over time. Once the smooth top layer of a concrete surface has flaked or broken away, the less durable and more porous center becomes exposed. This can result in small areas of pitting and flaking progressing into craters and severe dips in your floor. As well as the obvious tripping hazard, this will undermine the stability of your home over time by exposing the concrete to the elements more readily.
Furthermore, spalling can be a sign of more serious issues at work. For example, if you have fine hairline cracks or defects running through your concrete, moisture can seep in and exacerbate them. Spalling will be one of the first signs of this, but it can quickly progress into serious stability issues within the structure as a whole. As such, it is best to assess the situation as soon as possible.
Pitted, flaked, stained, or cracked concrete can be caused by many different issues, some of which are incredibly severe. If you try to address them alone, you run the risk of making things worse for your property and family in a number of ways.
Misdiagnosis Could Lead to Disaster
When addressing an issue like this, it is important that you identify all the underlying factors and account for them all in your solution. If you do not do this, you could end up making the problem worse with surprising speed. Packing filler into an unstable crack, for example, could make it spread and lead to a world of trouble.
Likewise, if you miss an underlying cause, you could implement an improper or unsuitable solution. This could simply cover the issue up until the damage shows through the repair work, or it could allow the issues at work to grow until the problem is too big to ignore. This could happen where damaged concrete is being caused by structural problems, for example.
Professionals Offer the Best Results
A professional is not only best placed to identify an issue and formulate a tailored solution, but they are capable of dealing with complicated or dangerous issues, like foundation damage and structural repairs. This means that expert assistance is more likely to give you a safe and speedy result that sticks the first time around.
It also means that you will get access to the best products, some of which are not sold through regular hardware stores. This means that while the cost of professional repairs can cause your eyebrows to rise at first glance, they are far more cost-effective in the long run than a DIY job will be. Finally, most professional services come with some kind of satisfaction guarantee—something that DIY simply cannot offer.
Concrete Pitting and Flaking: What Can Be Done?
There is not much you can do as a homeowner to deal with this kind of damage, even if it is purely cosmetic. You can, however, manage it by controlling the humidity and temperature in your home. Keeping these consistently within healthy parameters may prevent or slow the escalation of the issue, but the only way to get rid of the damage is to contact a professional.
A professional will first and foremost ensure that the damage is, indeed, purely cosmetic. Once they have done this, they will consider the state of the wall or floor. If it has started to bulge or sink, they will first lift the concrete. This could be done either with slab piers if the issue is with the foundation in your home, or via the PolyRenewal™ system. It depends on your particular situation and needs. Once the surface has been restored to optimum condition, they will discuss how to protect it from recurrence.
If the pitting and spalling were caused by the early stages of underlying structural damage this may be less of an issue. Any reputable professional will want to address the structural issues before the cosmetic damage. If the cosmetic damage was the result of adverse climatic or environmental conditions, they may suggest treating the concrete with certain products and sealing agents to prevent the recurrence of the issue in the long run. This can be a complicated process, as you can see, so it is best to get started as soon as you see problem signs.
Why Choose Foundation Recovery Systems?
Foundation Recovery Systems has been taking care of homes and homeowners in Missouri since 1992. From St. Louis to Kansas City, MO, our teams have helped thousands of homeowners to restore their concrete to health over the last two decades.
If you are concerned about signs of staining and spalling on your concrete surfaces, please contact our team today to schedule a free inspection and repair quote.