Concrete piers are poured or precast columns that transfer a building’s weight down to stable soil. A contractor drills a hole, fills it with concrete, and lets the pier carry the load below the zone where shifting soil caused the problem. Concrete is the most widely used man-made material in the world, and it is the default choice for many foundation repairs because it is reliable, solid, and long-lived. The same material family spans decorative products such as colorful concrete tiles and heavy structural elements like piers, which makes understanding concrete behavior valuable across the whole build.
Foundation problems show up as cracked drywall, sticking doors, sloping floors, and gaps around windows. When the cause is soil movement rather than a structural defect, piers are one of the most effective repair methods available. This article explains how concrete piers work, how they are installed, what they cost, and how they compare with steel and helical alternatives, so you can discuss options with a foundation contractor from an informed position.
What Concrete Piers Are and How They Are Built
A concrete pier is a column, typically round, square, or rectangular in cross-section, set into the ground to support a structure. For house foundations, piers are usually poured into drilled holes 6, 8, 10, or 12 inches in diameter, reaching below the frost line, which in cold regions sits around five to six feet down. In larger repair work, holes can run 12 to 20 feet deep so the pier base lands in stable soil. Because concrete is placed in a confined hole, good consolidation matters: consolidating concrete in congested reinforced members explains the vibration and placement techniques that prevent voids in tight sections.
Precast and cast-in-situ piers
Precast piers are manufactured in a factory, reinforced with steel wires or bars, and driven into the ground at the site. A cast steel shoe protects the tip during driving. Cast-in-situ piers are formed by drilling a hole and pouring concrete on site. Both approaches work; precast suits driven installation, while cast-in-situ adapts to variable depths and diameters.
Reinforcement and steel shoes
Steel bars can reinforce the concrete to add stability and strength. At the bottom of a driven pier, a cast steel shoe spreads the load and protects the toe from damage. In soil with soft layers, reinforcing the upper section resists bending as the pier passes from weak to strong soil.
| Parameter | Typical range |
|---|---|
| Diameter for house repair | 6, 8, 10, or 12 inches |
| Cross-section for heavy piers | 25 to 40 centimeters |
| Depth for house repair | Below frost line, about 1.5 to 2 meters |
| Length for heavy piers | Up to 25 meters |
| Clearance above grade | 0.3 to 0.45 meters (1 to 1.5 feet) |
Why Concrete Piers Work for Foundation Repair
Concrete piers work because they move the load path from weak surface soil to a bearing stratum deep enough to stay put. The pier itself is dense structural support, and when a row of piers is installed under a sagging foundation, each pier picks up its share of the building weight. Concrete is strong in compression, which is the dominant stress in this application. Compression strength is verified with standard cylinder or cube tests; the familiar 150 millimeter cube test exists because larger specimens give more reliable results than smaller ones, a point explained in this discussion of concrete cube test sizes.
Load transfer
A pier carries load two ways. End bearing transfers load through the pier base to firm soil, while skin friction carries part of the load along the pier sides. Designers size pier depth and diameter so the combination of end bearing and friction keeps settlement within acceptable limits.
Durability compared with wood
Wood piers rot where moisture collects, and they must eventually be replaced. Concrete does not rot, is not eaten by insects, and survives decades of ground contact. That durability is a core reason homeowners choose concrete over timber options.
Installation Process Step by Step
A typical residential pier installation follows a sequence that takes several days because concrete must cure before it carries load. Work through the steps in order and protect fresh concrete from rain and freezing. Where new concrete meets existing slabs or footings, surface preparation determines bond quality; pouring new concrete over an old surface covers the cleaning, profiling, and bonding steps that prevent delamination.
- Survey the foundation and mark pier locations from the repair plan.
- Drill a hole roughly one foot in diameter to the design depth, usually 12 to 20 feet for deep underpinning.
- Clean the hole of loose soil and standing water.
- Place reinforcement if the design calls for steel bars.
- Pour the concrete and consolidate it to remove voids.
- Let the concrete cure for six to seven days before loading.
- Install steel or concrete spacers between the pier tops and the foundation.
- Use hydraulic jacks to lift the home to the correct height.
- Close the gap between the foundation and the pier tops so the house rests level.
Curing and loading
Concrete gains strength over time, and the first week is critical. Keep the surface moist or covered during curing and avoid loading piers before the specified strength is reached. Strength gain continues for months, so early readings understate final capacity.
Lifting the structure
After curing, hydraulic jacks lift the home in small increments to its proper height. Lifting proceeds in stages to avoid cracking finishes, and the process stops when the foundation is level within the contractor’s tolerance. Spacers then close the gap and transfer the load permanently.
Concrete vs Steel, Helical, and Wood Piers
Foundation contractors choose between concrete, steel push piers, helical piers, and wood based on soil, load, and cost. Each option has strengths, and the cheapest upfront choice is not always the cheapest over 30 years. After installation, verify the work with the same care you would apply to any concrete element; post-concrete inspection and testing lists the checks that catch honeycombing, low strength, and misalignment before they become problems.
Steel push piers and helical piers
Steel push piers are driven to refusal and can reach deep bearing strata quickly, but they cost more per pier and can be overkill for light loads. Helical piers screw into the ground and suit tight access or situations where the repair must carry load immediately. Concrete piers cost less than steel in most markets and work just as well for typical house loads.
Wood piers
Wood piers are the low-cost option but have a shorter service life in damp soil. Most permanent repairs favor concrete or steel because replacement labor makes wood a poor long-term value.
| Type | Typical cost per pier (US) | Install speed | Service life |
|---|---|---|---|
| Concrete, poured | $400 to $1,200 | Days, curing required | Decades |
| Concrete, precast driven | $500 to $1,500 | 1 to 2 days | Decades |
| Steel push pier | $1,000 to $3,000 | Same day | Decades |
| Helical pier | $1,500 to $3,500 | Same day | Decades |
| Wood pier | $200 to $600 | Same day | 10 to 20 years |
Costs and When to Call a Contractor
Pier costs depend on depth, diameter, access, and how many piers the house needs. One or more piers may be required depending on how much the foundation has settled. For a typical home, a full perimeter repair runs from a few thousand dollars for a handful of piers to tens of thousands when the whole foundation needs underpinning. Prestressed and precast concrete options offer higher capacity per dollar in some soils, and the prestressed versus reinforced concrete comparison is a useful read when a project engineer proposes upgrading pier sections.
Cost factors
- Number of piers, driven by the settlement pattern
- Depth to stable soil
- Access and equipment mobilization
- Lifting and releveling labor
- Local permit and inspection fees
Getting a reliable quote
Ask for the soil investigation results, the pier schedule, and the load assumptions behind the design. A contractor who cannot explain why piers are spaced where they are should not get the job. Compare two or three quotes on the same scope.
Inspecting and Maintaining Pier Repairs
After the repair, verify the work: the foundation should be level, the piers should be visible above grade where designed, and the site should drain away from the structure. Concrete repairs need the same care as any concrete work, and the concrete gutters, walkways, and aprons around the house often need attention too; concrete gutter construction methods cover the forming, pouring, and finishing sequence that keeps water moving away from the foundation in the first place.
Signs that a foundation needs attention
- Cracks wider than about 3 millimeters in walls or brickwork
- Doors and windows that stick or no longer latch
- Sloping floors or gaps under skirting boards
- Separations where additions meet the main house
Verifying the repair
After lifting, give the house a few weeks to settle into its new position, then recheck doors and windows. Minor paint cracks can be patched once movement stops. Keep records of the pier schedule and depth for future buyers and for any warranty claims.