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What Is Bedrock?: Load-Bearing Strata and Your Foundation

When building a structure, it’s key to have the right foundation beneath it. This applies to both modest family homes and commercial, multi-floor buildings like hotels and shopping malls. They all need a strong and stable substructure to carry their weight. But despite their ability to distribute the load of the walls equally onto the ground, foundations also need to prevent water from coming inside the lower-grade levels.  

However, not every type of soil is the same. Their physical properties differ, allowing for varying results that will affect the building as a whole. It’s, hence, important for construction crews and engineers to understand geology, topography, and soil composition before they start the building process. Depending on the type of building they’re looking to make, the team will need to closely inspect the ground to see which kind of foundation will best suit the project. 

Read on as we introduce you to bedrock/load-bearing strata. This way, you’ll better understand how foundations work and why it’s important to have strong soil under them. 

What Is Bedrock/Load-Bearing Strata? 

dug out earth

Every homeowner needs to understand what this term means before we can go any further. But don’t worry, we’ll keep it short and simple. So, when someone mentions bedrock or load-bearing strata they’re talking about hard rocks and soil that lies beneath a building. The reason why they’re so important is the fact that they can carry heavy loads and stabilize structures. 

Bedrock/load-bearing strata don’t shift, compress, settle, or sink like some other types of soil. You can also hear people call them “non-active”, which is just a fancy way of saying they’re inert. Being inert stands for soil that doesn’t expand or contract like silty sand or clay soil. All these physical properties make them perfect for construction. 

Does This Mean That All Structures Need to Sit on Bedrock? 

It all comes down to the characteristics of the project, including the nature of the building, its load, soil properties, and your foundation budget. In some cases, the structure will need deep foundations, and they’re more costly and harder to build than shallow ones. 

But what is a deep foundation? It is a type of substructure that requires load-bearing strata to be present beneath the soft soil of the construction site. Nevertheless, those hard rocks and soil need to be at a reasonable depth. In case they’re not between 65 and 200 feet, the project will need to come up with another safe solution for the foundation. 

Different Types of Deep Foundations 

As we’ve said, deep foundations carry heavy loads and large buildings. But you can still employ them on various locations such as steep inclines, beaches, water, and other types of shifty surfaces. This means that they come in a couple of subtypes. 

Pile Foundations 

This subtype of deep foundation is perfect when the existing soil isn’t capable of carrying the load and shallow substructures aren’t an option. Construction crews install them by driving preformed units into the ground or by drilling. The units are tubes that builders will fill with concrete later on. Pile foundations are standard for waterfront construction, bridges, and multi-floor structures. 


Unlike the previous subtype of deep foundations, caissons are shallow. However, they can carry enormous weight. It’s common for engineers to use them when constructing bridges. Also, it’s worth it to mention that they go into the ground as a single unit. 

Hollow Box Foundations 

When you require a buoyant or semi-buoyant substructure, you should look no further than hollow box foundations. They will reduce the load on the soil to a minimum. When it comes to their construction, your crew can either go for open excavation or for sinking them into the ground like caissons. 

Basement Foundations 

Basement foundations are hollow substructures that are capable of providing homeowners with additional living or storage space. What makes them so popular is the fact that their design can vary depending on your needs. For construction, the builders will employ open excavation. 

Shaft Foundations 

When dealing with soft soil, there’s another construction option you can opt for. Shaft foundations go into the ground by drilling cylindrical holes. Builders fill them with concrete just like they do with pile foundations. They’re a popular choice when it comes to repairing already existing structures, but their downside is that they’re hard to install on underwater sand or soil with boulders. 

How Foundation Piers Use Load-Bearing Strata for Repair

pier bracket running down to bedrock load bearing soil

It’s not uncommon for homeowners in Michigan to have problems with a failing foundation. This happens when the soil beneath the structure is soft or experiences a change in its physical properties. When this occurs, the foundation will begin to sink into the ground, causing structural damage across the whole building. However, there’s a way to repair it. 

By driving foundation piers into the ground, the repair crew can stop the foundation from sinking and even lift it to its previous level. These piers are steel rods that come in two types; push and helical piers. They differ as push ones have corrosion-resistant coating and professionals drive them into the soil with a hydraulic ram. Helical piers work like screws, and they go into the ground with the use of a hydraulic torque motor. 

There are several benefits to foundation piers. Namely, they offer stability and are rather durable which allows them to hold your substructure for years to come. On the other hand, they’re cheaper to apply than replacing the whole foundation. And since it’s important to stay environmentally friendly these days, they also don’t cause any damage to their surroundings. Simply put, they check every box when it comes to failing foundation repair

In case your foundation is showing signs of sinking, you should act immediately. Of course, this doesn’t mean that you can repair it yourself. This job isn’t anything like a DIY project as it requires a team of professionals to mend the situation properly. We suggest that you contact FSM for a free inspection

Our team will come down to your place in no time. They will first assess the situation and then offer a range of solutions to repair your foundation. It’s best not to waste time and contact help as soon as you realize that there’s something wrong with your home. This way, the team will be able to act quickly and help you and your family enjoy the comfort of your home once again.

Load-Bearing Strata FAQs

Different soil types, such as expansive clay or poorly compacted soil, can exert pressure on foundation walls and contribute to cracks. Understanding your soil’s characteristics helps in devising effective repair strategies. 

Preventing soil erosion starts with effective landscaping techniques and moves to proper drainage systems. By combining these methods, you can significantly reduce soil erosion and protect your property’s structural integrity. 

Because soil expansion and soil shrinkage are something that occurs underground, it’s very difficult to detect when it occurs. Not only that, shrinking and expansion happen extremely slowly over the course of the year, so even if you could see what goes on under your home, you wouldn’t be able to spot changes instantly. If what you want to find out is whether or not expansive soil will cause or is causing your foundation problems, you’re better off checking for signs around your home instead of the soil. Of course, if there are problem signs, it means the soil expansion has been sufficient enough to warrant problems, and that might not be something you want to hear. However, unless you have foundation supports and a waterproofed crawl space or basement, the problems have already started.

The best place to check for soil problems would be the concrete outside your home and your basement or crawl space. Because of their proximity to the soil, these are the spots in your property that are affected first. Things like wall cracks, jammed doors, and sagging floors are really only relevant when the problems are significant, so don’t check for these signs if all you’re looking for is proof of soil expansion. You can inspect your concrete steps, driveway, and patio for any signs of settling, and if you see any, chances are, your soil is getting wet and expanding with frequency.

Another sign would be basement leaking or flooding. If your basement keeps flooding, especially when the water seems to be coming from where the wall meets the floor, it’s a very clear sign of soil issues. This kind of leaking occurs primarily when there’s hydrostatic pressure involved. Another good way to check would be to get a moisture meter to determine the humidity levels of the basement. If there are no leaking pipes and no way for water to get in yet the humidity levels are high, it means there’s enough water in the foundation’s soil to permeate through the basement walls.

Leah Leitow

Leah Leitow

Content Writer

Leah is a Content Writer for Groundworks with nearly ten years of experience working in the foundation repair industry. Her experience ranges from working with homeowners to find the right solution to training inspectors and staff. In her background as a Michigan journalist, she gained invaluable insight into people's lives throughout our state. Leah lives in metro Detroit with her husband and two sons.

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