What is a “Load-Bearing Strata” of Soil?

Over time, various factors including soil settling, improper construction, and soil erosion can cause your home’s foundation to sink or shift.

When this happens, it is essential to stabilize the foundation by reaching the load bearing strata, but what exactly is load bearing strata? Why does it matter, and how is it used to fix settled foundations?

Supporting a Foundation

In terms of soil, strata are layers, with the soil in each layer sharing similar characteristics.

Load bearing strata are layers of soil or rock that have the capacity to support the weight of a building structure. 

These strata are located at varying depths below the surface, depending on the geographical location and soil conditions. In general, the deeper the load bearing strata, the stronger they are, and the more they can support a building’s weight.

These strata are located at varying depths below the surface.

A foundation is the most critical element of any building structure, and it serves as the base that supports the entire weight of a building. The foundation is designed to transfer the building’s load to the underlying soil, which ultimately supports the structure. 

It is essential to stabilize a sunken foundation by reaching the load bearing strata because the foundation’s stability is crucial to the overall safety and longevity of the building. 

When a foundation sinks, it can cause cracks in the walls and floors, doors and windows may not close properly, and there may be visible signs of damage to the building structure. In extreme cases, a sunken foundation can lead to the collapse of the building, posing a severe safety risk to the occupants.

How to Reach Load Bearing Strata

Helical piers are a popular foundation repair solution used to reach the load bearing strata and stabilize a sunken foundation. 

Helical piers are steel piers that are driven into the ground to reach the load bearing strata. They are a preferred solution because they are fast, effective, and non-invasive. Additionally, they are suitable for a wide range of soil conditions, making them a versatile solution for foundation repair.

Drilling helical piers down to a load bearing strata is a reliable method for foundation repair because they are designed to withstand the weight of the building structure. 

Helical piers work by using a screw-like design that allows them to be driven deep into the ground until they reach the load bearing strata. Once the helical piers reach the load bearing strata, they are attached to the building’s footing by a bracket. This transfers the load of the structure off of the soil immediately underneath and on to the piers, providing a stable and secure foundation for the building.

How Deep Are Load Bearing Strata?

In Texas, the soil and strata makeup varies depending on the region. 

The state has several soil types, including sand, clay, loam, and silt. Additionally, the underlying strata can vary, with some regions having shallow load bearing strata, while in others the piers need to be installed deeper.

In the eastern part of Texas, the soil is primarily composed of clay and loam, with some areas having sandy soils. The load bearing strata in this region is typically shallow, with some areas having a depth of only a few feet. 

In the central region of Texas, the soil is a mix of clay, loam, and sand, with the load bearing strata varying in depth from a few feet to several hundred feet. This region has a diverse soil composition, making it essential to conduct a soil analysis to determine the soil’s characteristics and the depth of the load bearing strata. This analysis is critical in determining the appropriate type and length of helical pier required for foundation repair.

In West Texas, the soil is predominantly composed of clay and sand, with some regions having gravel soils. The load bearing strata in this region can be shallow or deep, with some areas having a depth of several hundred feet. The deep strata in West Texas makes it challenging to reach the load bearing strata, and the use of helical piers is essential for foundation repair.

Hitting Bedrock

What is below the various strata of soil? That would be bedrock.

How is Bedrock formed?

Bedrock is created through a natural geological process that involves the formation and consolidation of rock over millions of years. There are several processes involved in the creation of bedrock, including:

1. Cooling and Crystallization: One of the most common ways that bedrock is formed is through the cooling and crystallization of molten rock. When magma (molten rock) cools and solidifies, it forms an igneous rock. If the cooling process is slow, the rock formed is coarse-grained and forms granite, while a fast cooling process results in a fine-grained rock such as basalt.
2. Deposition and Compression: Sedimentary rock is formed through the accumulation of sediment, such as sand, mud, and organic matter. As the sediment accumulates over time, it undergoes a process called compaction, where the weight of the overlying material compresses and solidifies the sediment into rock.
3. Metamorphism: Metamorphic rock is formed through the transformation of pre-existing rock under intense heat and pressure. This process occurs deep beneath the Earth’s surface and results in a change in the rock’s mineral composition and texture.

It is important to note that the creation of bedrock is a slow and ongoing process that occurs over millions of years. The type and characteristics of bedrock depend on various factors, including the type of rock, the geological processes involved in its formation, and the environmental conditions in which it is formed.

The Stability of Bedrock

In addition to being the foundation of many landscapes and geological features, bedrock also plays an essential role in providing stability and support for structures such as buildings and bridges.

The properties of bedrock, such as its strength, stability, and load bearing capacity, make it an ideal material for supporting heavy loads and resisting external forces.

The bedrock in northwestern Texas is primarily composed of sedimentary rocks that were formed during the Paleozoic era, approximately 540 to 250 million years ago. These rocks were created through the deposition and compaction of sediment, such as sand, mud, and organic matter, in ancient shallow seas that covered the region. They are characterized by their unique geological formations and features, such as fossilized marine life, cross-bedding, and evaporite deposits.

While these features provide valuable insights into the geological history of the region, our primary interest in bedrock is its strength.

While the depth of bedrock varies across the region, in areas where it is closer to the surface it gives a fallback option should we not find a load bearing strata of soil above it.

At Childers Brothers, We Know Soil

Foundation fixes can fail if they aren’t backed by the proper information. It does no good to slap helical piers onto the house if you don’t know how to calculate when the piers have reached a load bearing strata of soil.

We deal in science-based solutions, not guesswork. And we know the science of soil, whether it be drilling down to find stability or altering the makeup of expansive soils near the surface to prevent upheaval.

Contact us today for a free 27-point analysis.