There are two kinds of concrete: the kind that has cracked, and the kind that is going to crack...
How do expansive soils cause problems for concrete slabs?
The freezing temperatures in Minnesota can result in some pretty dramatic heaving, movement, and cracking if the soils beneath a concrete slab aren’t chosen and prepared correctly and don’t have proper drainage. When we perform a home inspection, our inspectors at HomePro Inspections are looking for and documenting any potential issues with concrete slabs.
What are expansive soils?
Expansive soils are a type of soil that is known for its ability to swell and shrink in response to changes in moisture levels and temperatures. In this part of the country, blue and green clays are problematic. This can cause serious problems for structures built on these soils, as they can crack foundations and damage sidewalks and roads. In order to mitigate the risks posed by expansive soils, engineers typically use special foundations and construction techniques. However, even with these precautions, damage from expansive soils can still be a problem.
How do expansive soils affect concrete slabs?
When concrete cracks, it's usually because of expansive soil rising and settling. Also known as "swelling clay," expansive soils can wreak havoc on everything from sidewalks and patios to foundations.
Expansive soils contain minerals that absorb water and expand when wet. This can put tremendous pressure on concrete, causing it to crack and crumble, rise, or settle. In some cases, the damage can be so severe that the entire slab needs to be replaced.
Correct Base Material
There are several ways to deal with expansive soil, but the most important thing is to make sure that any concrete slab you pour has the correct base materials, appropriate drainage, and is properly reinforced. This will help reduce the risk of cracking and also provide some protection if the cracks do occur. Be sure to consult with a qualified contractor before beginning any concrete project in an area with expansive soils.
How do freezing temperatures affect expansive soils?
The problem lies in the fact that concrete is porous, meaning that it can absorb water from the ground below. When this water freezes, it expands, putting pressure on the slab above. Over time, this can cause cracks to form in the concrete. In severe cases, the entire slab can even collapse. So, if you live in an area with cold winters, it's important to keep an eye on your concrete slabs and take steps to prevent them from being damaged by freezing temperatures.
Why is it important to repair cracks in concrete?
Concrete slabs are subject to all sorts of stressors: expansion and contraction due to temperature changes, the weight of vehicles, and even just regular foot traffic. Over time, these stresses can cause cracks to form in the concrete.
Safety Hazards
While some cracks are purely cosmetic, others can pose a serious safety hazard. For example, if a crack is deep enough, it can cause a trip and fall accident. In extreme cases, cracked concrete can even collapse and settle entirely. That's why it's important to repair cracks in concrete as soon as they're discovered. By filling in the cracks, you'll not only improve the appearance of your concrete, but you'll also help to prevent further damage due to freeze-thaw cycles. To help our clients, we try to define concrete cracks as maintenance items or recommended repairs in our home inspection reports. This helps to prioritize how these issues are resolved.
What are the best methods for repairing cracks in concrete?
Concrete is a sturdy material that can last for many years with proper care. However, even the most well-constructed concrete slab is not immune to cracks. While small cracks may not seem like a big deal, they can cause serious damage if left unaddressed. Fortunately, there are a number of effective methods for repairing cracks in concrete.
Epoxy Resin
One popular method is to fill the crack with a flexible epoxy resin. This type of resin is designed to expand and contract as the temperature changes, which helps to prevent the crack from reappearing. Epoxy resins are available in a variety of colors, so you can also use this method to improve the appearance of your concrete.
Polymer-based Concrete Leveling Compound
Another option is to fill the crack with a polymer-based concrete leveling compound. This type of compound can be applied using a simple caulk gun, and it will harden in just a few hours. Once it's hardened, the concrete leveling compound will help to level out any uneven surfaces and prevent the crack from spreading.
Conclusion
Cracks in concrete are not only unsightly, but they can also pose a serious safety hazard. Fortunately, there are a number of effective methods for repairing cracks in concrete. By filling in the cracks, you'll not only improve the appearance of your concrete, but you'll also help to prevent further damage and keep your sidewalks, driveways, and patios safe.
Visit our website to learn more or to schedule your home inspection in the Rochester, Owatonna, and Faribault, MN areas. You can contact us today at (507) 202-8942 or use our online “Schedule Now” feature to set up an appointment.