Foundation Piers, Piles, and Anchors: What’s the Difference?
Foundation repair involves many components, often described with interchangeable terminology. When discussing piers, piles, and anchors for deep foundations, earth retention, and foundation underpinning, we must first understand and compare the geotechnical terms.
This page defines foundation piers, piles, and ground anchors, compares their differences, and highlights their similarities for a clearer understanding.
What’s the Difference Between Foundation Piers, Piles, and Anchors?
Foundation piers, piles, and anchors are components used to stabilize and support damaged foundations. While all are used for foundation repair, each stabilizing element functions differently. Let’s begin by discussing foundation piles.
What are Foundation Piers?
Foundation piers are similar to piles, driven or drilled deep into the ground to transfer a structure’s load to stable soil. They stabilize foundations with uneven settling and strengthen those unable to support the structure’s weight.
Foundation piers are made of concrete, masonry, or steel, with soil conditions, load demand, and the project budget determining which is used. Pier types include:
Push Piers
Push piers are hydraulically driven deep into the soil, reaching load-bearing strata. These steel piers stabilize and lift settling foundations.
Helical Piers
Helical piers are hydraulically driven into the ground. Their screw-like structure rotates deep into the soil, making them ideal for unstable or wet soil areas.
Slab Piers
Slab piers are driven into the ground beneath existing concrete slab foundations. They lift and stabilize slab-on-grade structures.
Drilled Piers (Caissons)
Drilled Piers, known as Caissons, are a type of deep foundation. They are installed by drilling holes and then filling them with concrete. Drilled piers provide high load-bearing capacity for large structures.
Concrete Piers
Concrete piers are built by pouring concrete into a pre-dug hole. They are used for shallow foundations or to reinforce footings in residential structures.
Micropiles (Mini Piles)
Micropiles have a smaller diameter than other foundation piers. They support existing foundations in confined spaces with limited access or those with nearby buildings or other structures.
Segmented Piers
Segmented piers consist of individual concrete sections driven or drilled separately into the ground. These foundation piers are used for low-to-medium loads.
Steel Piers
High-strength steel piers are driven into the soil to significant depths. These piers are chosen for their robust durability and extreme load-bearing capacity.
What are Foundation Piles?
Foundation piles are installed deep underground, transferring a structure’s weight to stable soil layers. These components lift and reinforce sinking or weak foundations and are typically made of precast or cast-in-place concrete, steel, or timber piles. Foundation piles ensure structural stability and longevity in compromised soil or under extremely heavy loads.
Foundation pile types are selected based on soil conditions, load requirements, application, design, and budget. Common types include:
Material-Based Piles
- Concrete Piles: Pre-cast or cast-in-place concrete
- Steel Piles: H-piles, pipe piles, sheet piles
- Timber Piles: Treated timber piles
Function-Based Piles
- End-Bearing Piles: Transfer loads to the load-bearing stratum below ground. Suitable for bedrock or dense soil.
- Friction Piles: Develops surface friction to resist the load. Suitable for soft soil.
Installation Method-Based Piles
- Cast-in-Place Piles: Bored piles, auger cast piles, CFA piles, cased and grouted piles, and fully bonded uncased and grouted piles installed by drilling, augering, or jetting
- Driven Piles: Hammer or vibratory-driven piles
Specialized Foundation Piles
- Helical Piles: Used for light to medium loads in areas with limited headspace.
- Hollow Bar Micropiles: Used in foundation underpinning for existing foundations
- Soil Displacement Piles: Used in soft soil and installed with minimal disturbance to surrounding soil
- Composite Piles: These piles combine the high strength and durability of steel and concrete piles
Before installation, foundation repair professionals inspect the area, diagnose the underlying problem, and devise a repair plan tailored to your property and budget.
Foundation Piers vs. Foundation Piles: What is the Difference?
Foundation piers and piles stabilize various foundation types in varying soil conditions. Though they are similar, several key differences exist, including material, size, installation method, and load transfer.
Foundation Piers
- Material: Concrete, steel, masonry, or composite materials
- Size: Varies significantly
- Installation: Drilled, pressed, or driven
- Load Transfer: Primarily end-bearing, but can include skin friction
Foundation Piles
- Material: Concrete, steel, timber, or composite materials
- Size: Smaller in diameter
- Installation: Drilled, drilled, screwed, or jetted
- Load Transfer: End bearing and skin friction load bearing
What are Foundation Anchors?
Foundation anchors, like helical anchors or ground anchors, resist tension and uplift forces by securing structures to the ground. This makes them ideal for anchoring retaining walls, securing steel or wood to slab foundations, and repairing bowing basement walls. Anchors prevent horizontal or vertical foundation movement by utilizing tiebacks for lateral horizontal applications and anchor piles for vertical applications. Several foundation anchors exist. Though similar, they contain slight differences.
Earth Anchors
Earth anchors are also called ground anchors or soil anchors. They are installed in the ground, providing vertical support to the compromised foundation. The three common earth or ground anchor types include:
- Deadman Anchors: Buried horizontal timbers or concrete blocks anchored to the structure, providing lateral support.
- Rock Anchors: Installed in rock formations. They use drilled holes and high-strength bolts or bars to provide support.
- Soil Nails: Steel bars installed in rock or soil to reinforce slopes and prevent soil erosion.
Tieback Anchors
Tieback anchors resist lateral horizontal forces. They are best used for slope and retaining wall stabilization.
Helical Anchors
Helical anchors resist lateral tension or uplift forces. The blade penetrates the soil, stabilizing temporary structures on slopes or anchoring retaining walls.
Anchor Piles
Anchor piles are large, vertical piles anchored into the ground for support. They resist uplift forces and can be used for deep excavations.
Foundation Piers, Piles, and Anchors: The Bottom Line
Foundation piles, piers, and anchors stabilize damaged foundations, providing support and enhanced safety. While piers and piles are similar, they differ in size and material: piles are long, slender, and driven deep into the ground, while piers are larger concrete components. Both can function as anchors when used to resist forces, with anchoring referring to how a pile or pier vertically or horizontally resists tension or uplift.
Groundworks Provides Customized Foundation Solutions
Noticing signs of a weakening foundation, cracks, or other damage? Contact Groundworks for a free inspection and answers to your questions. We provide comprehensive foundation assessments to diagnose underlying issues, ensuring every repair strategy is tailored to your unique needs and budget.
Foundation Pier FAQs
Foundation piers attach to your home’s footing. If your home doesn’t have a closed footing modifications can be made.
Consult a qualified foundation repair expert to help ensure your foundation is properly evaluated and factors like soil composition, and local building codes are considered.
Foundation piers are typically a permanent solution. Once installed correctly by a reputable foundation repair company, high-quality foundation piers can last for the lifetime of your home.
Unlike temporary fixes such as patching or filling cracks, foundation piers provide a long-term solution to foundation problems and prevent future damage.
Some people who have had problems with foundation sinking are suspicious when they hear that helical piers can raise their foundation back to the original level. After all, it’s absolutely true that your home and its foundation are incredibly heavy; that’s why the foundation is sinking, after all. Could these piers really make it easier for your foundation to stop sinking and raise the foundation up?
- Incredible Strength
Helical piers have hydraulic drivers in them, which means they’re incredibly strong. This is one reason that helical piers can actually raise the foundation. Because they’re so strong, they can support the entirety of your home’s foundation without having to rely on the soil underneath the foundation.
- Lots of Force
Once you have helical piers underneath the foundation, they can push up with a lot of force. You might have to see it to believe it, but it’s true that helical piers can make sure your foundation goes back to its normal space.
