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Bedrock and Load-Bearing Strata

Bearing the weight of the structure above them, bedrock/load-bearing strata are key to your home’s stability.

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No matter what kind of structure you’re building, it’s essential to choose the right foundation beneath it. Both family homes and multi-floor commercial buildings need a strong substructure to keep them safe and standing. The foundation has two main purposes — to distribute the weight of the walls onto the hard rock under it and to prevent groundwater and moisture from entering the lower level of the structure. But what happens if the soil on which the building sits upon is shifting and likely to suffer from compression? 

Well, it’s key for builders and engineers to understand geology, topography, and soil composition to construct a stable structure. Besides the building’s type and size, they’ll use their understanding of the area to determine the right foundation. Read on to learn more about bedrock and load-bearing strata, so you’ll know how foundations work. 

What Are Bedrock and Load-Bearing Strata? 

Before you install the foundation, you’ll need to know what these terms mean. Namely, bedrock and load-bearing strata refer to the hard rock and soil beneath a structure. Their purpose is to carry weight because they don’t shift or compress. Furthermore, they don’t settle or sink. 

Experts call them “non-active”, which means that they’re inert. They don’t expand or contract like silty sand and clay soil. In other words, load-bearing strata are ideal for construction. 

Do All Structures Need to Be Built on Bedrock? 

Depending on the structure’s nature, its load, soil properties, and the cost of the foundation, a structure may or may not need to be built on bedrock. Construction may require a deep foundation. These are more costly and harder to build than shallow ones. 

Deep foundations require load-bearing strata to be under the soft soil of the location. Of course, the bedrock must be at a reasonable depth, generally between 65 and 200 feet.  

Deep Foundation Types 

As you know by now, deep foundations support heavy loads and large structures. However, you can use them to do their thing even on steep inclines, beaches, over water, and some other shifting surfaces. As such, they come in different subtypes. 

  • Pile foundations: Builders construct pile foundations by driving preformed units into the ground or by drilling. These units are tubes that they later fill with concrete. Pile foundations are useful when the soil isn’t capable of carrying the load and shallow substructures simply aren’t an option. They’re common for waterfront construction, bridges, and multi-floor buildings. 
  • Caissons: These foundations are hollow, but they can withstand enormous weight. As such, engineers use them for bridges. They go into the ground as a single unit. 
  • Basement foundations: These are hollow substructures that provide you with both storage and living space underneath the ground. Builders construct them through open excavation. Depending on the homeowner’s requirements, their design can vary greatly. 
  • Hollow box foundations: Creating a semi-buoyant or buoyant substructure, hollow box foundations reduce the load on the soil to a minimum. Builders can construct them through open excavation or sink them similar to caissons. 
  • Shaft foundations: By drilling a cylindrical hole, builders use shaft foundations and fill them with concrete when working on soft soil. They can suit existing structures but can be difficult to install on underwater sand or soil with boulders. 

Which Type of Foundation Do I Need? 

The question of what foundation type is suitable for you depends on a couple of factors. However, before we mention them, you’ll need to know that it’s best to leave this to professionals as they’ll make the right decision. Nevertheless, it all comes down to the type of home you’re looking to build, as well as its size and the soil of the construction site. Depending on these factors, you’ll either end up with a deep or a shallow foundation. 

Using Piers to Repair Foundation Damage 

If your home is sitting on soft soil without adequate support, it will eventually begin to sink and settle into the ground. This will endanger the structural integrity of the building, leaving you and your family living in unsafe conditions. Luckily, there’s a way to solve this. Construction crews use foundation piers to deal with this problem. Here’s what they do. 

This is a technique where builders drive steel pipes into the ground beneath your home, so they can correct the failing foundation. They can either use push, helical, or slab piers in the process. Push piers are steel pipes with a corrosion-resistant coating that technicians drive through the soil with a hydraulic ram. On the other hand, helical piers work like screws that go into the ground using a hydraulic torque motor. Slab piers are specific to homes with a settling slab foundation. 

Foundation piers have numerous advantages. Firstly, they’re stable and pretty durable structures and can hold your foundation for years to come. They’re less costly than having to replace the whole foundation. But apart from that, piers are also environmentally friendly, causing little to no damage to their surroundings. All in all, they’re your best choice when it comes to a failing foundation. 

Professional Help 

In case you’re looking to repair your settling foundation, it’s best to contact professionals. Trying to do it yourself isn’t advised in any way. No matter what knowledge or experience you have, this isn’t a one-man job. Hence, we strongly suggest that you reach out to our team in Tennessee and Alabama at AFS for a free inspection and repair estimate

Our experts will be more than happy to visit your place and look at your foundation. After inspection, they’ll offer you solutions that will fit your problems as well as your wallet.

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