Foundation Piering & Underpinning Cost Calculator
Determine the exact number of steel push piers or helical piles your settling home requires. Calculates code-mandated pier spacing, bedrock depth extensions, and hydraulic lift fees.
Push Pier & Helical Pile Sizer
Select your pier technology, linear settled footing, and bedrock depth below for a certified ICC-ES takeoff.
Foundation Piering & Underpinning SizerICC-ES AC358 Standard
Calculates pier counts, depth to load-bearing strata, and hydraulic manifold lifting costs.
Standard installation covers up to 20 feet. Drives exceeding 20 feet add steel tube extension costs.
Zero phone lead auctions. Single verified foundation underpinning contractor in your county.
Understanding Foundation Piering & Underpinning
When subsoil shrinks during droughts or loses bearing capacity due to poor drainage, the footing sinks. Underpinning is the structural engineering process of transferring the home's dead and live load past weak upper soil strata directly down to solid bedrock or competent load-bearing earth.
Commission-based foundation sales representatives frequently recommend more piers than code requires to increase contract totals. This calculator uses International Code Council Evaluation Service (**ICC-ES AC358**) criteria to give homeowners an honest, mathematically verified pier takeoff.
Pier Technology Comparison: Push vs Helical vs Concrete
| Pier System | Average Cost / Pier | Installation Technique | Best Soil Conditions | Lifespan |
|---|---|---|---|---|
| Steel Push Piers | $1,500 - $3,500 | Hydraulically driven using house reaction weight | Dense clay over solid bedrock (15 - 50+ ft) | Lifetime |
| Helical Piles | $1,800 - $4,000 | Mechanically torqued screw blades into soil | Lighter homes, porches, wet sand, high water table | Lifetime |
| Pressed Concrete Cylinders | $950 - $1,800 | Precast concrete segments pressed sequentially | Shallow stable soils (prone to misalignment) | 10 - 20 Years |
How Pier Quantity & Spacing Is Calculated
Piers cannot be placed arbitrarily. Under International Building Code (IBC) Section 1810, the spacing interval is governed by the structural stiffness of the concrete footing and the dead load of the walls above:
Standard residential wood frame single-story footprint.
Tighter spacing prevents concrete shear between brackets.
Maximum load support for heavy structural stone or multi-family.
Contractor Fine Print: Depth Extension Clauses
Nearly every foundation contractor bid includes up to 20 or 25 feet of driven steel in the base price. If your property sits on deep expansive clay (such as the Texas Blackland Prairie or Missouri clay), crews may drive piers 30 to 45 feet before reaching load-bearing refusal. Always check your contract's rate per extra foot ($35 to $55/ft) before signing.
Frequently Asked Questions About Foundation Piering
How much does foundation piering cost per pier? +
The national average cost to install a foundation pier ranges from $1,500 to $3,500 per pier for steel push piers, $1,800 to $4,000 per pier for helical screw piles, and $950 to $1,800 for segmented concrete cylinders. Total project costs typically range between $9,000 and $25,000 depending on the number of piers required.
How many foundation piers does my house need? +
Under ICC-ES AC358 engineering criteria, foundation piers are typically installed every 6 to 8 feet along the settled section of the footing. For a single-story home with 24 linear feet of sinking corner, 4 to 5 piers are required. Two-story homes or structures with heavy masonry veneer require tighter 6-foot spacing to support the concentrated dead load.
Which is better: steel push piers or helical piers? +
Steel push piers are best for heavy structures and deep load-bearing bedrock; they use the home's own weight to hydraulically drive steel pipe into rock. Helical piles feature corkscrew blades twisted mechanically into soil, making them superior for lighter structures (porches, decks, additions) and unstable soils where bedrock is excessively deep.
Are foundation piers a permanent structural repair? +
Yes. When galvanized steel push piers or helical piles are driven past the active soil zone into competent bedrock or dense load-bearing strata, the repair is permanent. High-quality pier systems carry 25-year to lifetime transferable manufacturer warranties.