Foundation Underpinning Cost Calculator

Underpinning typically runs $1,000 to $3,000 per pier installed, with most homeowners paying around $1,200 to $1,800 per pier. Because most jobs use 4 to 12 piers, total projects commonly land at $5,000 to $25,000, with a typical settling repair around $10,000 to $15,000. A small job (a few piers, easy access) can be $4,000 to $8,000, while many deep piers, difficult access, and full engineering can top $30,000. The pier count is the biggest driver, followed by the pier type, the depth to stable soil, site access, and the engineering required. Enter your pier count, type, depth, access, and engineering in the calculator above for a localized estimate — and get an engineer's assessment for an accurate pier count.

Underpinning is the structural repair that strengthens a settled or sinking foundation by extending its support down to deeper, stable soil or bedrock — usually by driving or screwing steel piers beneath the footings and transferring the home's weight onto them. Rather than resting on unstable surface soil that has shifted, the foundation ends up carried by piers that reach firm strata, which halts further settlement and often lifts the foundation back toward level. It's needed when a foundation has settled because the soil can no longer support it — from expansive clay, poor compaction, erosion, or footings that were built too shallow. Unlike cosmetic crack patching, underpinning addresses the root cause (inadequate support), making it the permanent fix for foundation settlement.

The signs all point to settlement — the foundation dropping unevenly. The classics are stair-step cracks in brick or block walls, diagonal cracks running from the corners of doors and windows, sloping or uneven floors (a ball rolls on its own), doors and windows that stick or won't latch as the frame goes out of square, and gaps opening around windows, doors, and trim. A chimney pulling away from the house, a separating porch or stoop, and widening exterior foundation cracks are red flags too. Not every crack means underpinning — thin hairline cracks from normal curing are usually cosmetic. The concerning signs are those showing ongoing movement, especially several together or worsening over time. If you see them, get a structural engineer's assessment.

Piers are installed only along the settling section of the foundation — not necessarily the whole perimeter — spaced roughly 6 to 8 feet apart (closer for heavier loads or weaker soil). Most residential jobs use 4 to 12 piers, though a long run or a heavy, severely-affected home can need 15 to 25+. A short corner might take 3 to 6, one full side 6 to 10, and a whole side of a heavy home 10 to 15+. The exact count and layout are engineered from the length of the affected area, the structure's weight, the soil, and each pier's capacity, with piers concentrated at load points like corners and under load-bearing walls. Since cost is per pier, the count is the biggest price factor — so an engineered count, not a guess, gives an accurate quote.

Neither is universally better; a structural engineer picks based on your home's weight and the soil. Push (resistance) piers are hydraulically driven straight down using the home's own weight as resistance until they hit load-bearing strata — ideal for heavier, multi-story or masonry homes that provide enough weight to drive deep. Helical (screw) piers are augered into the ground like a giant screw and don't need the structure's weight to install, which suits lighter structures, new construction, softer soils, and tight spaces; capacity is verified by installation torque, and they're also used as tiebacks for bowing walls. Both are proven, permanent solutions when properly engineered, and they cost in a similar range per pier. The right type for your load and soil matters far more than the small price difference.

Yes, significantly. Piers must reach load-bearing strata — dense soil or bedrock — and the deeper that layer sits, the more pier sections, drive time, and equipment work each pier takes. A standard depth is the baseline; reaching deeper to stable soil adds about 20% per pier here, and very deep drives to bedrock add about 45%. Depth varies across a site and isn't fully known until piers are driven to refusal, which is one reason a geotechnical soil report is valuable — it estimates the bearing depth so the design and quote are realistic. Two identical-looking homes can have very different underpinning costs purely because one sits over shallow bedrock and the other over deep, soft fill.

Properly engineered and installed, underpinning is a permanent fix — the piers transfer the home's load to stable strata that won't settle, halting movement, and reputable contractors back it with a long-term, often lifetime and transferable, warranty. Galvanized steel piers last for decades. 'Permanent' does assume it's done right: the correct pier type, depth, and count, driven to genuine load-bearing strata. It is absolutely not a DIY project. Underpinning requires a structural engineer to diagnose the cause and design the repair (pier type, depth, count, load calculations), a specialized contractor with hydraulic drivers and lifting equipment to install it, and permits and inspections because it's structural work affecting the home's integrity. DIY would be unsafe, unpermitted, and would void any warranty. Hire qualified professionals.

For underpinning, yes on the engineer, and often on the soil report. A structural engineer should diagnose the settlement, confirm underpinning is the right fix, and design the pier layout — the type, depth, count, and placement — and their stamped plan is frequently required for the permit. Because contractors have an incentive to recommend their own products, an independent engineer protects you from an over- or under-designed repair. A geotechnical soil report adds another layer: it measures the soil's bearing capacity and the depth to stable strata, which sharpens the pier design and depth estimate. The report isn't always required, but on a large or uncertain job it prevents surprises. The calculator includes engineering levels and a soil-report add-on so you can price both.

Often, partially or fully — but not always, and not always advisably. As the piers are installed and load-tested, the crew can jack against them to lift the settled foundation back toward its original position, which can close cracks and re-level floors. How much lift is recovered depends on how long the settlement has existed, the construction type, and the risk of cracking finishes during the lift. Sometimes full recovery is achievable; other times the safer goal is to stabilize the foundation where it is and stop further movement, accepting a small permanent offset rather than risking new cracks by forcing it all the way back. A good engineer sets a realistic lift expectation up front. Either way, the primary purpose — permanently halting settlement — is achieved.

Most residential underpinning jobs take a few days to about a week, depending on the pier count, type, depth, and access. Each pier involves excavating at its location, attaching a bracket to the footing, driving or screwing the pier to load-bearing strata, then load-testing and lifting — so a small 4-to-6-pier job may be 2 to 4 days, while a large or deep job with many piers runs a week or more. Difficult access (tight spaces, interior slab piers, heavy landscaping) and very deep drives add time. The front-end engineering, soil report, and permitting can add lead time before work starts. The hands-on installation is relatively quick and far less disruptive than a full foundation replacement, which is a major advantage of underpinning.