Foundation Pier Systems for Repairing Settling Homes

Foundation pier systems have long stood as the ideal solution for repairing settling homes and commercial buildings in Florida. While the ultimate goal of lifting and stabilizing foundations remains consistent across all pier systems, the methods for achieving these results differ based on their installation method.

Several factors are considered in determining which foundation pier system is the most suitable for every foundation repair, including the structure's weight, its location, and the conditions of the underlying soil. 

Foundation Pier Systems

Before we explore the different types of foundation pier systems most commonly used to repair settling foundations in Florida, let’s first cover what exactly piering does. 

Whenever signs of foundation damage are observed, such as wall cracks and sticking window and door frames, a foundation inspection is carried out to identify if and where settlement is occurring. Once settlement has been confirmed, foundation piering is the go-to solution for permanent stabilization.

Foundation piering, also referred to as underpinning, entails the installation of vertical support anchors below a foundation. These anchors - or piers - serve to transfer the weight of the structure to solid bedrock or deeper, more stable soils than those near the surface.

Once these piers have reached their proper depths and have successfully stabilized the foundation from settling further, an attempt to lift the foundation back to its original position can then be executed.

The methods used to achieve this stabilization vary depending on the foundation pier system that is utilized. Let’s explore the most commonly used foundation pier systems.

Push Pier System

The push pier system utilizes steel tubes that are first bracketed to the footing of a foundation and then hydraulically pushed into the soil below using the structure's weight until solid bedrock is reached. From here, the piers push against the bedrock until the foundation begins to lift or until the desired amount of pressure is achieved.

At this point, the weight of the home or building is then transferred to the load-bearing bedrock from the unstable soil near the surface. If proper lift to the foundation hasn’t occurred yet, an attempt may be made at this step, but only if it can be safely conducted and with the approval of the property owner.

Push piers are often preferred to be used on heavier structures such as multi-level homes and larger commercial buildings. Properties that are located near or along the Florida coasts where bedrock is relatively more shallow may find push piers to be beneficial. More inland properties can also make great use of push piers as they can reach greater depths than other solutions but will require more materials to reach the deeper bedrock.

Helical Pier System

Steel helical piers feature helical-shaped plates attached at the base of the pier and operate similarly to screws. Unlike push piers, they are not mounted directly to a bracket at the foot of the foundation at first but are mechanically driven into the soil until they reach the required torque and capacities.

The heavy steel brackets are then positioned against the footing of the foundation, whereupon the weight of the structure is then transferred to the helical piers and down into the stronger, load-bearing soils below. It is at this point that lifting the home or building back into its original position can be attempted.

Helical piers offer a variety of alternative benefits from their push-pier counterpart. They can be installed much faster than push piers because they do not need to be driven down to bedrock. Instead, they are mechanically screwed into the ground until they reach stable soils that offer the required torque to support the foundation effectively.

While helical piers may encounter challenges in rocky soils, they can be easily installed in the majority of soil compositions. Helical piers are also better suited for stabilizing lighter structures and areas of the home where the weight is not as significant and can be installed with smaller equipment.

Helical piers also have the added feature of being able to be installed to support a foundation prior to the construction of a new home or building. With their pre-construction placement, helical piers can provide permanent stabilization right from the start, greatly reducing the risk of foundation settlement issues in the future.

Injection Pier System

Injection piers are primarily employed by foundation repair specialists to stabilize settling foundations affected by sinkhole activity. These piers utilize a combination of foundation underpinning and soil compaction methods to lift a foundation back to its original position.

Injection piers are steel pipes that are driven deep into the ground similar to push piers, where once the appropriate depths have been reached, perforated openings at the bottom can allow for debris to be flushed out with water. Aggregate-free cement, often referred to as grout, is then injected down the pipe, out of the perforated openings, and into the surrounding soil. The compacted grout at the bottom provides the necessary support for the piers to push up through the attached bracket at the footing of the foundation, lifting it to its original position.

Two main types of injection piers are used depending on the specific needs of a foundation:

• Grouted Pressure Underpins. These injection piers are hydraulically advanced into the ground until they reach just above limestone bedrock. The injected grout then seals off the underlying bedrock from further erosion, providing greater support to the structure and underlying soil.
  
  
• Helical Injection Piers. Operating similarly to standard helical piers, helical injection piers are mechanically driven into the soil until the desired resistance is achieved. The soil around the base of the pier is then consolidated with the injection of grout through the perforated openings.
  
  Injection piers are employed in highly specific scenarios, particularly in cases of sinkhole damage, providing effective stabilization solutions for foundations affected by these issues.

Interior Slab Pier System

Oftentimes when foundation settlement occurs, the concrete slabs inside a home or building can become damaged and settle as well. Slab piers can be utilized to elevate the interior slab from below and back into its original position with permanent stability. The initial step involves drilling appropriately sized holes through the concrete slab at each installation location to access the soil underneath. From here, one of two slab pier types may be utilized:

• Push-type Slab Piers. Push-type slab piers are hydraulically driven into the ground underneath the slab. A slab bracket is placed in the hole to allow for the extension of the flanges on the bracket to provide support to the underside of the slab. Steel tubes are then driven through the bracket until proper depths have been reached.
  
  
• Helical Slab Piers. Helical blades at the bottom of the shaft of this type of pier will allow for it to be mechanically advanced into the soil below until competent, stable soils have been reached. After the completion of this step, a specialized slab bracket is placed around the pier to provide support to the concrete slab from underneath. 

 

Both of these foundation slab pier systems will then work to properly transfer the weight of the concrete slab to the appropriate load-bearing strata below. Lifting the slab back to its appropriate level can then be attempted at this step, and all voids that were created from the piering process will be carefully filled with grout. The holes drilled at each pier location will finally be filled and sealed with concrete, completing the installation process.

Finding the Right Solution for Your Foundation

With the multitude of foundation pier systems available, there is likely more than one solution that can be utilized to repair your foundation if settlement has occurred. Fortunately, choosing the right system doesn’t have to be your choice or concern. An expert foundation repair contractor can evaluate the specific characteristics of your foundation and recommend the appropriate system for repair and long-term stabilization.

Since 1989, LRE Foundation Repair has been redefining the foundation repair industry in the state of Florida, earning the trust of thousands of communities for their foundation stabilization needs. Schedule a free inspection today to find out what solutions LRE Foundation Repair can provide for your unique foundation repairs.