Why Does Concrete Sink and/or Crack?

If you own a home in the State of Florida and are experiencing problems with your concrete sinking or cracking, there are some logical explanations as to why this is occurring. Unless the ground was properly assessed and stabilized during pre-construction, components such as a slab, sidewalk, driveway, and even concrete pool decks can sink and crack. The good news, modern applications like poly foam injections can lift and repair just about any concrete problem that Florida homeowners may be experiencing today.

What Makes Concrete in Florida Sink and Crack?

In order to understand why this phenomenon occurs, it’s important to understand the composition of the soil that is trying to support the weight of such concrete structures. While a bag of premix concrete typically weighs 80lbs, concrete when used for building structures can weigh 150lbs per cubic foot. Meaning, concrete slabs for average homes (24’x48’) in residential neighborhoods of Tampa, Naples, Orlando, Ft. Myers, and others can weigh between 5-10 tons fully cured.

The next thing to consider is the weight of building materials coupled with furniture and even people. Altogether, the ground your house is resting on is trying to support anywhere between 15-20 tons, if the soil is not properly reinforced, concrete will eventually settle, causing it to sink and crack. This can frustrate a lot of homeowners who have spent a significant amount of money either building or buying a new house.

If you are in the process of designing a new home and want to build it in the State of Florida? It is paramount to contact a professional ground improvement company to assess your soil and make the necessary modifications in order to prevent excessive sinking and settlement in the near future.

The Soil in Florida

The soil in Florida is not typical of other locations where water tables and soil composition must be considered before construction begins. The State of Florida is covered in more than 1.5 million acres of sand called Myakka, which is quite visible no matter where you go. Additionally, Florida also has a lot of clay soil, wetlands, sinkholes, and water flowing underneath the ground.

There are 12 basic “soil types” in the US alone and Florida contains about seven of them. The most common soils in the state of Florida are rich in organic matter, acidic, and dark in color. Depending on where you live, the soil can vary from city to city. For example, the soil in Orlando is very sandy and clay-based while the southern part of the state contains a mixture of sand, clay, and peat moss where marshes and bogs are more common.

Below are the seven types of soil found throughout the state of Florida:

Alfisols: This is a clay-rich soil that generally retains moisture and can decay quickly. It can be found along the east coast, southwest locations, and northwest coast.
Entisols: Are mostly undeveloped soils that can be found in areas such as flood plains, sand dunes and slopes. This type of soil is common in the panhandle, south coast, and central Florida.
Histosols: Found mostly in marshes and swamps in southern Florida. This is a good agricultural soil but can deteriorate rapidly without moisture in the soil.
Inceptisols: This type of soil can be found in central, east coast locations of Florida, and in the Everglades. Oftentimes this soil is very shallow with bedrock located underneath the soil.
Mollisols: Are found in most wetlands and contain dark and organic matter. They can hold a large amount of water and are scattered throughout the state. It’s not typically found in swamps or marshes, but rather underneath wet grasslands.
Spodosols: This is a very common type of sand-based soil found in central, eastern, and western cities such as Orlando, Tampa Bay, Ft. Myers, and Naples, etc. It is light-colored in nature, can be found a few inches under the topsoil, and generally has a high sand-content.
Ultisols: Ultisols are very much like Alfisols but lack its nutrients. It can be found along the northwest coast, east coast, and southwest regions of Florida.

Methods for Repairing Sinking & Cracked Concrete

While some settlement is normal after the construction of a concrete structure is complete, the reason why concrete cracks and sinks are due to the conditions of the soil in which it was built. Before concrete structures like a driveway, sidewalk, foundation, slab, or concrete pool deck can be constructed, it’s always more feasible in the long run to have a ground improvement expert inspect and stabilize your soil.

Before new technologies evolved into the industry for lifting and repairing concrete slabs, mudjacking was about the only choice that a homeowner had at their disposal to fix their problem. However, the problem with mudjacking, it creates a huge mess and is rather time-consuming. Poly foam jacking is a lot cleaner and doesn’t require the use of heavy equipment and is also hydrophobic. Meaning, water has no effect on its ability to support concrete structures, and it will not deteriorate as mud does.

Although mudjacking had its place and purpose at one time, poly foam grout injections today are:

• More precise and level
• Better load-bearing solutions
• Less messy and time-consuming
• Faster to repair and cure
• Ready to use shortly after installation
• Less expensive

Repair Your Concrete with Polyurethane Grout Injections

If your home’s foundation, slab, garage, tennis court, patio, or concrete swimming pool deck is sinking or cracked, it can be easily repaired with polyurethane grout injections. Polyurethane grout injections are small holes that are drilled into the concrete where voids or loose granular soils are present. Next, they’re filled with poly foam at predetermined depths and flow-rates to lift and raise sinking and cracked sections of concrete to within 1/8” of accuracy.

And lastly, once the poly foam has cured and your concrete is repaired back to its original condition, technicians will cover the drilled holes with cement grout or epoxy and level them off, leaving virtually no mess behind. By and large, this application is the most logical solution for Florida homeowners who care about their landscaping because heavy equipment is not required with polyurethane grout injections.

The process is amazingly fast and offers homeowners the use of their concrete within hours after installation and can cost far less than deploying a small army of excavation equipment across your lawn. If you want your concrete repaired with guaranteed results, then you should contact a soil remediation specialist like Helicon and get started today because it will only get worse with time.