Foundation Piers: Types, Uses & What to Expect
Learn how foundation piers support a home, the differences between push piers, helical piers and drilled piers, and what to understand about installation, stabilization, lifting and cost before approving a repair.
What Are Foundation Piers?
Foundation piers are structural support elements that may be used to transfer building loads to suitable supporting material beneath an existing foundation. They are commonly discussed as a repair option for certain foundation settlement and support problems.
Foundation piers are not all installed the same way. Common types include:
- Push piers: Steel pier sections advanced using a reaction force, often from the structure.
- Helical piers: Steel shafts with helical plates installed by rotation into the ground.
- Drilled piers: Engineered elements constructed in drilled openings, commonly using reinforced concrete.
The appropriate pier type, depth, number and location depend on the foundation, structural loads and ground conditions.
If a contractor has recommended foundation piers, you may have questions about what they actually do. Will they stop your house from sinking? Will they lift a sloping floor? How are they installed, and how does a contractor decide where to place them?
These are important questions because installing piers is more than placing steel or concrete beneath a foundation. A pier system must provide an appropriate load path from the structure to suitable supporting material.
This guide explains the main foundation pier types, how they differ, what installation may involve and which questions to ask when reviewing a proposal.
How Do Foundation Piers Work?
A foundation transfers the weight of a building into the ground. If the supporting soil or other material cannot adequately support the foundation under the relevant conditions, movement or distress may develop.
An appropriately designed pier system may provide an additional path for transferring loads to suitable material at depth.
The Pier, Bracket and Foundation Connection
In some retrofit systems, a bracket connects the pier to the existing foundation. The bracket and connection are important because they transfer loads between the building and the pier.
Other systems may use different connections or construction methods. The design must account for the existing foundation and the loads being supported.
How Deep Do Foundation Piers Go?
There is no universal installation depth for foundation piers. Depth depends on the pier system, ground conditions, design requirements and installation criteria.
A pier should not be selected or judged solely by a promised depth. Ask how the proposed system will establish that the required support has been achieved.
What Is Foundation Underpinning?
Underpinning is a broad term for work intended to strengthen, extend or otherwise improve the support of an existing foundation. Foundation piers are one possible underpinning approach, but not every underpinning project uses piers.
When Are Foundation Piers Used?
Foundation piers may be considered when an evaluation identifies a support problem that an appropriate pier system can address. Their use depends on the diagnosis, not simply the presence of a crack or uneven floor.
Foundation Settlement
Settlement involves downward movement of a foundation or its supporting material. Differential settlement, where parts of a structure move by different amounts, may contribute to cracks, misalignment and uneven floors.
A pier system may be considered for certain settlement problems when additional support is needed and the proposed system is suitable for the property.
Learn more in Foundation Settlement: Causes, Signs & Repair Options .
A Sinking Foundation
Homeowners often describe a low corner or downward movement as a sinking foundation. Before piers are recommended, the condition should be evaluated to determine whether the foundation actually moved and what caused it.
See our sinking foundation warning signs guide .
Other Engineered Support Applications
Piers may also be used in other engineered foundation support applications. The design must match the structure, loads, site conditions and intended performance.
A Foundation Crack Does Not Automatically Mean You Need Piers
Cracks can result from different conditions. Some may need monitoring, sealing or a different structural repair. Pier installation should be supported by an appropriate diagnosis.
Start with our guide to foundation crack types and causes .
Types of Foundation Piers Used for Repair
The terms used in foundation repair estimates can be confusing. Pier systems differ in how they are installed, how they develop support and how they connect to the structure.
1. Push Piers
Push piers generally consist of steel sections advanced into the ground using a hydraulic reaction force. In many retrofit systems, the existing structure provides the reaction during installation.
A bracket may connect the installed pier to the foundation. The system is intended to transfer the specified load through the connection and pier.
Because installation relies on reaction forces, the condition and capacity of the existing structure are relevant to the design and installation process.
2. Helical Piers
Helical piers are steel shafts with one or more helical plates. They are advanced into the ground by rotation using suitable installation equipment.
The plates, shaft and connection are selected for the intended structural loads and ground conditions. Installation measurements may form part of the project-specific acceptance criteria.
Helical piers are used in some retrofit and new-construction foundation applications. Whether they are appropriate for an existing home depends on the design.
3. Drilled Piers
Drilled piers are constructed in excavated or drilled openings. Depending on the design, they may include reinforced concrete and may be used to transfer loads to suitable supporting material.
Drilled pier work may require equipment access, excavation, reinforcement, concrete placement and appropriate construction controls.
The term “drilled pier” covers more than one possible design. A contractor or engineer should identify the actual system proposed.
4. Other Pier and Underpinning Systems
Some projects use other engineered support systems, including different deep foundation elements or underpinning approaches. Product names and regional terminology may vary.
Rather than relying on the name alone, ask how the system works, what supports the load and how its performance will be evaluated.
Push Piers vs. Helical Piers vs. Drilled Piers
These systems are not interchangeable simply because they all provide foundation support. The comparison below describes general differences.
| Feature | Push Piers | Helical Piers | Drilled Piers |
|---|---|---|---|
| General installation | Steel sections are advanced using a reaction force. | Helical plates and shaft are rotated into the ground. | An opening is drilled and the designed element is constructed. |
| Common material | Steel | Steel | Often reinforced concrete |
| Important design consideration | Available reaction, structural connection and ground support. | Shaft and plate design, installation criteria and ground support. | Ground conditions, geometry, construction quality and load transfer. |
| Possible application | Certain existing foundation underpinning projects. | Certain retrofit and new-foundation support projects. | Engineered deep foundation and support projects. |
| Key question | Can the existing structure safely provide the required installation reaction? | What design and installation criteria establish the required support? | What ground and construction conditions govern the pier design? |
Which Pier Type Is Right for Your House?
The answer depends on the structure, loads, existing foundation, soil conditions, access and repair objectives. A pier type should be selected through an appropriate design process, not solely by comparing product descriptions.
What to Expect During Foundation Pier Installation
The installation process varies by pier system and property. A retrofit project may involve excavation near the foundation, installing structural connections and advancing the selected piers.
The following steps describe a general project sequence, not a universal installation procedure.
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Evaluation and Repair Planning
The condition is evaluated, the repair objective is defined and the proposed system is selected. Engineering and ground investigation may be needed.
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Site Preparation
The contractor plans access, identifies relevant utilities and prepares the work areas. Landscaping, paving or other features may affect access.
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Excavation and Foundation Access
For some retrofit systems, soil is excavated near designated foundation locations so that the connection and pier can be installed.
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Pier Installation
The selected pier system is installed using its specified equipment and procedures. Installation measurements and observations may be recorded as required by the design.
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Structural Connection and Load Transfer
The system is connected to the foundation using the specified details. The repair plan should define how loads are transferred to the new support.
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Any Specified Elevation Adjustment
If the design includes a lifting or elevation correction objective, that work is performed under the applicable plan and limitations. Not every project includes lifting.
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Documentation and Site Restoration
The contractor completes required records, inspections and site restoration within the agreed scope. Ask which documents you will receive at completion.
Can You Stay in Your House During Pier Installation?
Occupancy depends on the repair scope, access, structural condition and safety requirements. Ask the contractor whether any rooms, utilities or areas will be unavailable during the work.
Will Pier Installation Damage Landscaping or Concrete?
Some projects require excavation or access through landscaping, paving or other surfaces. The proposal should explain what must be disturbed and which restoration work is included.
Do Foundation Piers Stabilize or Lift a House?
Foundation stabilization and foundation lifting are different objectives. A pier system may be designed to provide additional support without attempting to restore the building to an earlier elevation.
Stabilization
Stabilization generally focuses on providing the required support and addressing the diagnosed structural condition. The expected performance should be defined in the repair plan.
Elevation Recovery
Some projects may include an attempt to recover elevation or improve alignment. The amount of correction that is appropriate or achievable depends on the existing structure and its condition.
Why a House May Not Return to Its Original Position
A structure may have undergone movement, distortion or damage that limits how much correction can safely be attempted. The original elevations may also be unknown.
Even after foundation support is addressed, doors, windows, drywall, flooring or other finishes may require separate work.
Get the Expected Result in Writing
Before approving pier installation, ask whether the contractor is proposing stabilization, lifting or both. The written proposal should explain the intended outcome and any important limitations.
What Foundation Piers Cannot Fix by Themselves
Foundation piers can be useful for certain support problems, but they are not a universal solution for every foundation symptom.
Water Intrusion
Piers do not automatically seal leaking cracks or correct water entering a basement or crawl space.
Foundation Drainage Guide →Every Foundation Crack
A crack may need a separate repair after its cause is addressed. Some cracks are unrelated to a pier-repair objective.
Foundation Crack Repair →Bowing Basement Walls
A wall moving inward may require evaluation of lateral pressure and an appropriate wall repair system.
Bowing Wall Repair Options →Damaged Floor Framing
Sagging joists, beams or subfloor materials may need a separate repair even if the foundation is adequately supported.
Uneven Floors Guide →What About Expansive Soil and Foundation Heaving?
Expansive soil and upward foundation movement present different design considerations from ordinary downward settlement. Piers should not be assumed to solve a heaving problem without an appropriate evaluation.
Learn about foundation heaving and expansive soil and foundation damage .
How Much Do Foundation Piers Cost?
The cost of foundation pier installation depends on much more than the price of an individual pier. A repair estimate should account for the required system, structural connections, installation conditions and associated work.
Factors That Affect Foundation Pier Costs
- The type and design of pier system.
- The number and locations of piers.
- The foundation type and condition.
- Ground conditions and installation requirements.
- Excavation and equipment access.
- Engineering, permits and required inspections.
- Any specified lifting or elevation correction.
- Landscaping, concrete and other restoration work.
Is a Price Per Pier Enough to Compare Estimates?
Not by itself. A quoted price per pier may exclude engineering, excavation, brackets, access work or restoration. Different proposals may also specify different numbers or types of piers.
Compare the complete written scope, not only the unit price. Ask how the proposed pier locations and quantities were determined.
For additional cost considerations, read Foundation Repair Cost: What Affects the Price? .
Questions to Ask Before Installing Foundation Piers
A useful foundation pier proposal should explain the diagnosis, repair design, installation process and intended outcome. These questions can help you understand what you are being asked to approve.
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What Evidence Shows That My Foundation Needs Piers?
Ask what measurements, observations or evaluations support the proposed repair. If the cause remains uncertain, ask whether additional investigation is appropriate.
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Why Was This Pier Type Selected?
Ask how the chosen system fits your foundation, structural loads, soil conditions and site access.
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Who Determines Pier Locations and Quantities?
Request an explanation of how the repair layout was developed and whether engineering design is required.
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How Will the Required Support Be Verified?
Ask what installation criteria, records or inspections apply to the proposed system.
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Will the Work Stabilize, Lift or Both?
Clarify the repair objective and whether any elevation correction is included or expected.
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What Additional Repairs May Be Needed?
Ask whether crack repair, drainage work, flooring repair or other work is included or may be necessary separately.
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What Is Included in the Warranty?
Request the actual written warranty and review its coverage, exclusions, duration, transfer terms and claim procedure.
When to Seek an Independent Evaluation
If a proposal involves major structural work, substantial expense or a diagnosis you do not understand, consider an independent licensed structural engineer. A geotechnical evaluation may also be appropriate for certain ground-related concerns.
See our foundation inspection guide and foundation repair estimates guide for more questions to ask.
Foundation Piers FAQs
What do foundation piers do?
Foundation piers may provide additional structural support by transferring specified building loads to suitable supporting material. Their suitability depends on the foundation, ground conditions and design.
Are push piers or helical piers better?
Neither system is universally appropriate. Push piers and helical piers use different installation methods. The choice depends on the structure, loads, soil conditions, access and repair objectives.
How deep are foundation piers installed?
There is no universal depth. Installation depends on the pier type, ground conditions and project-specific design criteria. Ask how the required support will be established.
Will foundation piers stop my house from sinking?
An appropriately designed pier system may address certain diagnosed settlement or support problems. Whether it is suitable for your house depends on the cause of movement and the repair design.
Do foundation piers lift a house?
Some pier projects include an elevation correction objective, but others focus on stabilization. Lifting is not guaranteed, and the appropriate amount of correction depends on the structure.
Can foundation piers fix cracks in my walls?
If foundation movement contributed to the cracks, a suitable support repair may address part of the underlying problem. Existing cracks and finishes may still require separate repairs.
Can foundation piers be installed inside a house?
Some projects may involve interior work, depending on the foundation and repair layout. Interior installation can require access through floors or other components. The proposal should explain any required disturbance and restoration.
How many foundation piers does a house need?
The required number depends on the diagnosed condition, structural loads, pier capacity, foundation layout and repair design. A pier count should not be determined solely from the size of the house.
How long does foundation pier installation take?
The schedule varies with the number and type of piers, site access, ground conditions, excavation and associated work. Ask for a project-specific schedule that identifies possible delays.
Are foundation piers a permanent fix?
Pier systems are intended to provide structural support according to their design, but no contractor should promise that every future foundation problem is eliminated. Performance depends on design, installation, ground conditions and other relevant factors. Review the written warranty and its limitations.
Do I need a structural engineer before installing piers?
Engineering and permit requirements vary by project and jurisdiction. For significant structural work or an uncertain diagnosis, an independent licensed structural engineer may be appropriate. Ask who is responsible for the repair design.
Educational Disclaimer: Cracks in My Foundation provides general homeowner education. This guide is not a structural inspection, geotechnical evaluation, engineering design or property-specific repair recommendation. Pier selection, installation and structural performance depend on site-specific conditions and applicable requirements. Consult appropriately qualified professionals before authorizing structural repairs.