What Are The Types of Foundation Repair Piers and How Are They Used?

Your home’s foundation is its backbone, providing stability and support to the entire structure. Over time, foundations can experience settlement or shifting, leading to structural damage or further issues. When this happens, foundation repair becomes necessary. 

Configuring a solution for foundation repair is completely dependent on the load of the house, location for installation, including soil types and geological makeup, property grade, and drainage, which makes each case unique. One common method for restoring a stable foundation is the use of foundation piers. At R&R Foundation Specialist, we are equipped with the industry’s best tools and practices to advance our use of piers as we repair, reinforce, and stabilize residential and commercial foundations.

Foundation piers are used to stabilize a home’s foundation, oftentimes offering repair to damaged foundations. Simply put, the process of piering, or underpinning, is the act of transferring the weight of a home from an unstable foundation to the piers which are anchored into the stable ground. 

Using foundation piers offers an efficient and instantaneous fix to a serious problem that many homeowners face that can have lasting negative effects on a structure.  We partner with Precision Piers, a local manufacturer that we source all of our products from right here in Everette, Washington!

While there are many pier types, industry standards focus on two primary types of piers: eccentric helical piers and concentric push piers. Push piers are most commonly used since they are better suited for heavier structural loads, can be pushed deeper into foundations, and can be installed in tight spaces. 

It’s important to assess each property individually as this can more accurately determine which type of pier is needed and how it will affect the outcome of the repair methods. At R&R Foundation Specialist, our team of structural engineers work with a wider range of pier types which has resulted in better outcomes for properties across Puget Sound and Western Washington.

Know the Difference Between Eccentric and Concentric Piers

Eccentric piers and concentric piers are terms often used in the context of structural engineering and construction. They refer to different arrangements of loads or forces applied to a pier or column. The key difference between concentric and eccentric piers is the alignment of the applied load. Concentric piers have the load applied at the centerline, while eccentric piers have the load applied off-center, creating both axial and bending forces that need to be accounted for in their design and construction.

Concentric:

Concentric piers are designed to have the axial load or force (vertical load) applied at the center of the pier. In other words, the load is applied in a straight line through the central axis of the pier. They are considered to be heavy load-bearing. 

Typical Uses:

• They are typically used in situations where the load is evenly distributed or where the primary concern is to support vertical forces without significant lateral or eccentric forces.
• Concentric piers are commonly used in simple columns and structures where the load is evenly distributed. Read more about concentric piers.

Eccentric:

Eccentric piers, on the other hand, have the axial load applied at a distance from the centerline of the pier. This means that the load is not aligned with the central axis of the pier and creates a moment or bending force in addition to the vertical load. They are considered to be light load-bearing. 

Typical Uses:

• They are used in situations where the applied load is not aligned with the central axis of the pier or column, and there is a need to consider both the vertical and lateral forces.
• Eccentric piers are common in structures where there are horizontal or lateral forces, such as in buildings subjected to wind loads or earthquake forces. They are designed to resist both the axial and bending loads. Read more about eccentric piers. 

Push piers derive their name from their hydraulic press-driven process, wherein sections of pipe are pushed into the ground. These piers have a hollow structure that is capped on the ends, that enables smooth insertion into the soil. Helical piers share similarities with push piers as they are also constructed from galvanized, rust-resistant steel.

However, the distinction lies in their versatility and design. While push piers consist of lengthy, cylindrical poles, a helical pier resembles a large screw.

Eccentric Helical Piers

Helical piers, or helical piles, are steel tube-like structures made of galvanized steel and concrete that provide excellent stability for various types and sizes of buildings. They anchor the structure’s weight to the surrounding ground, offering exceptional foundational support.

How It Works: These piles are installed deep into the ground, sometimes in sections for optimal effectiveness, and screwed directly into the soil. 

Pros:

1. Optimal Installation: a quick, easy, non-invasive installation that doesn’t require heavy equipment or excavation and can be used in areas with limited access. They can be installed in all weather conditions, including rain.
2. Cost Effective: more cost-effective than traditional foundation systems, particularly in areas with poor soil conditions. They require less excavation, which reduces the amount of material that needs to be removed and the cost of disposal. Additionally, their installation process is generally quicker and less labor-intensive
3. Versatile: can be used in a wide variety of soil conditions, including soft or loose soils, as well as in areas with high water tables. They can be installed in both residential and commercial construction projects and can support a wide range of structures, including decks, homes, bridges, and towers.
4. Ideal Impact: causes limited environmental impact due to lesser need for larger equipment and excavation and the slow, methodical lift is less jarring to the foundation, maintaining the structural integrity of the home.

Uses of Eccentric Helical Piers:

1. Foundation Support:
   • Residential Buildings: Provide support for new construction or underpin existing foundations in homes.
   • Commercial Structures: Support larger buildings, warehouses, and industrial facilities.
   • Infrastructure Projects: Used in the foundations of bridges, towers, and other civil engineering projects.
2. Retrofitting and Repair:
   • Foundation Repair: Stabilize and lift sinking or settling foundations.
   • Retrofitting: Enhance the load-bearing capacity of existing structures without extensive excavation
3.   Specialty Construction:
   • Boardwalks and Decks: Support for elevated walkways and decks, especially in unstable or water-logged soils.
   • Retaining Walls: Provide lateral stability and prevent wall movement or failure.
   • Solar Panel Arrays: Support the foundations of ground-mounted solar panels, ensuring they remain level and stable.

Features and Advantages:

1. Installation:
   • Ease of Installation: Installed using hydraulic machinery that screws the piers into the ground, causing minimal disturbance to the surrounding area.
   • No Excavation Needed: Unlike traditional piles, helical piers do not require large-scale excavation, making them ideal for sites with restricted access.
2. Versatility:
   • Various Soil Conditions: Effective in a wide range of soil types, including clay, sand, and loose or water-saturated soils.
   • Load-Bearing Capacity: Designed to carry both compression and tension loads, making them suitable for diverse applications.
3. Durability:
   • Corrosion Resistance: Often galvanized or coated to protect against corrosion, extending their lifespan.
   • Long-Term Performance: Provide reliable long-term support with minimal maintenance.
4. Adjustability:
   • Depth Adjustment: Can be installed to varying depths to reach stable soil layers or bedrock, depending on the project’s needs.
   • Load Testing: Easily load-tested during installation to verify their capacity and ensure they meet the required specifications.
5. Environmental Impact:
   • Low Environmental Impact: Minimal soil displacement and reduced noise and vibration during installation make them environmentally friendly and suitable for sensitive sites.

In summary, eccentric helical piers are versatile, efficient, and durable foundation elements used to provide stable support for a wide range of construction projects, from residential buildings to large infrastructure developments. Their ease of installation and adaptability to different soil conditions make them a preferred choice for both new construction and foundation repair.

Concentric Push Piers

Concentric push piers are similar to Eccentric Push Piers through the hydraulic press-driven installation. Concentric push piers offer reliable support for vertical settlement issues and even load distribution but may have limitations, particularly in terms of lateral support and installation costs.

How It Works: These push piers are driven or pushed into the ground beneath a foundation to lift and stabilize it. They are designed to evenly distribute the vertical load (concentrically) along the central axis of the pier, helping to support and lift the structure.

Pros:

1. 1. Effective Installation: easy and non-invasive installation methods that can often be completed in areas with low headroom or limited access.
   2. Precise Load Distribution: Concentric push piers apply the load (vertical force) directly along the central axis of the pier, providing precise and uniform support to the foundation. This can be advantageous when even load distribution is critical.
   3. Effective for Vertical Settlement: Concentric piers are well-suited for addressing vertical settlement issues, such as a sinking foundation. They can effectively lift and support the structure to its original position. These piers can be used for various types of structures, including residential, commercial, and industrial buildings.
   4. Ideal Impact: causes limited environmental impact due to lesser need for larger equipment and excavation and the slow, methodical lift is less jarring to the foundation, maintaining structural integrity of the home.

Uses of Concentric Helical Piers

1. Foundation Support:
   • Residential Buildings: Used to support the foundations of new homes or underpin existing ones to prevent settlement.
   • Commercial Structures: Provide stable foundations for offices, industrial buildings, and retail spaces.
   • Infrastructure Projects: Utilized in the foundations of bridges, roadways, and other significant civil engineering works.
2. Retrofitting and Repair:
   • Foundation Repair: Stabilize and lift existing foundations that are sinking or settling.
   • Structural Enhancement: Used to increase the load-bearing capacity of existing foundations without major excavation.
3. Specialty Construction:
   • Boardwalks and Decks: Provide support for elevated structures, particularly in areas with unstable or moist soils.
   • Retaining Walls: Offer additional stability to retaining walls to prevent movement or failure.
   • Solar Panel Foundations: Serve as foundations for ground-mounted solar panels, ensuring they remain stable and level.

Features and Advantages:

1. Installation:
   • Ease of Installation: Installed using hydraulic machinery that screws the piers into the ground, causing minimal disruption to the site.
   • No Extensive Excavation: Unlike traditional deep foundation methods, concentric helical piers do not require large-scale excavation, making them suitable for tight or restricted sites.
2. Versatility:
   • Adaptable to Various Soil Conditions: Effective in diverse soil types, including clay, sand, silt, and areas with high water tables.
   • Load-Bearing Capacity: Capable of supporting both compression and tension loads, making them versatile for different types of structures.
3. Durability:
   • Corrosion Resistance: Often galvanized or otherwise treated to resist corrosion, enhancing their longevity.
   • Long-Term Performance: Provide reliable and stable support over long periods with minimal maintenance.
4. Adjustability:
   • Depth Flexibility: Can be installed to various depths to reach stable soil layers or bedrock, depending on the project’s requirements.
   • Load Verification: Load testing can be performed during installation to ensure that the piers meet the required specifications.
5. Environmental Impact:
   • Minimal Environmental Disturbance: The installation process involves little soil displacement and generates low noise and vibration, making it environmentally friendly and suitable for sensitive areas.

In summary, concentric helical piers are a reliable and efficient solution for deep foundation support across a variety of construction projects. Their central alignment ensures even load distribution, and their ease of installation and adaptability to different soil conditions make them a preferred choice for both new builds and foundation repairs.