Foundation repair costs range from $2,000 for minor crack patching to $25,000 or more for full pier installation or underpinning on a large home, per HomeGuide cost data compiled from contractor quotes nationwide. The type of foundation problem, your home's size, and the method required drive the price far more than geography.
What Does Foundation Repair Cost on Average?
The national average for foundation repair sits at $4,500 to $7,500, according to Angi and HomeGuide cost surveys. That average, however, blends a wide range of job types -- minor crack sealing on one end and full underpinning on the other. Understanding which category your home falls into is the critical first step before getting quotes.
| Repair Type | Typical Cost Range | What It Addresses |
|---|---|---|
| Hairline crack injection | $300 - $800 per crack (est.) | Cosmetic or shrinkage cracks |
| Basement wall crack repair | $500 - $2,500 per crack (est.) | Leaking or growing vertical cracks |
| Carbon fiber strap installation | $4,000 - $8,000 per wall (est.) | Bowing basement walls |
| Mudjacking / slab lifting | $600 - $2,000 per section (est.) | Sunken concrete slabs |
| Pier installation (underpinning) | $1,000 - $3,000 per pier (est.) | Settlement, differential movement |
| Full underpinning (whole house) | $10,000 - $25,000+ (est.) | Severe settlement, unstable soil |
| Drainage correction | $1,000 - $5,000 (est.) | Water-related foundation stress |
Cost estimates from HomeGuide cost data and contractor quote surveys. Per-pier costs reflect push piers; helical piers run slightly higher at $1,500 to $4,000 each.
Crack Repair: When Minor Is Not Minor
Not every crack in a foundation wall is an emergency. Contractors and structural engineers classify cracks by width, orientation, and activity:
Low urgency: Hairline vertical cracks under 1/4 inch wide that are dry, not growing, and uniform width from top to bottom. These are typically concrete shrinkage cracks that form as concrete cures. Epoxy injection seals them for $300 to $800 per crack and prevents water intrusion.
Medium urgency: Stair-step cracks in block foundations or diagonal cracks at corners of openings. These can indicate differential settlement. A structural engineer evaluation ($300 to $700) should precede any repair to confirm the settlement has stopped before sealing.
High urgency: Horizontal cracks in basement walls indicate lateral earth pressure and should be evaluated by a structural engineer immediately. Carbon fiber strap systems, which bolt to the floor and ceiling to prevent further movement, cost $4,000 to $8,000 per wall and require professional installation. Some horizontal crack situations require full wall replacement.
Monitor Crack Width With a Crack Monitor
If a crack is visible but you do not know whether it is growing, glue a crack monitor (a plastic gauge available at hardware stores for under $15) across it and photograph it monthly. A crack that does not change in width over 6 to 12 months is stable. A growing crack requires a structural engineer evaluation before any cosmetic repair -- sealing a growing crack does not fix the underlying movement.
For guidance on finding and verifying a contractor qualified to do this work, see how to vet a contractor's license and insurance before signing any foundation repair agreement.
Pier Installation: The Standard Fix for Settlement
When a foundation has settled -- sunk unevenly into soft or eroded soil -- pier installation (also called underpinning) is the industry-standard repair. Contractors drive steel piers through the settling soil to bedrock or a stable load-bearing layer below and then use hydraulic jacks to lift the foundation back toward its original elevation.
Types of piers and their costs:
Push piers (also called resistance piers or hydraulic piers) are driven by the weight of the house. They cost $1,000 to $3,000 installed per pier and are the most common choice for residential settlement repair. A typical single-story home needs 8 to 12 piers; two-story homes often need 12 to 20.
Helical piers are screwed into the ground like a giant bolt. They work in soft soils where push piers cannot develop enough resistance and cost $1,500 to $4,000 per pier. Helical piers are also used in situations where a foundation is being extended into soft fill.
Total project cost: For a 1,500 square foot ranch home with moderate settlement requiring 10 push piers, expect $10,000 to $20,000 all-in. A 2,500 square foot two-story with severe settlement requiring 15 to 18 piers can reach $25,000 to $40,000. These are real project costs, not worst-case scenarios -- pier installation is one of the most expensive home repairs a homeowner will face.
Get a Structural Engineer Opinion First
Before accepting a foundation repair company's diagnosis and quote, pay $300 to $700 for an independent structural engineer (PE) to assess the problem. Foundation repair companies earn money from large repairs -- some will recommend pier installation for cracks that only need monitoring or minor sealing. A structural engineer has no financial interest in recommending a specific repair method and will give you an unbiased assessment of severity, urgency, and appropriate repair approach.
Mudjacking and Foam Lifting for Sunken Slabs
Mudjacking (also called slabjacking or pressure grouting) injects a cement-soil slurry under a sunken concrete slab through drilled holes to fill voids and lift the slab back to grade. Polyurethane foam lifting (marketed under names like PolyLevel or FoamWorks) injects expanding foam instead of slurry. Both methods address the same problem: a sunken sidewalk, garage floor, driveway, or patio slab.
Cost comparison:
- Mudjacking: $600 to $1,400 per section, slightly lower material cost
- Foam lifting: $800 to $2,000 per section, faster cure (15 minutes vs 24-48 hours), lighter material (reduces risk of re-sinking in soft soils), longer warranty
Neither method repairs a structurally cracked or broken slab. If the slab is shattered or has large irregular cracks, removal and replacement (concrete slab replacement at $6 to $12 per square foot) may be more cost-effective than lifting damaged sections.
Does Foundation Repair Require a Permit?
Yes, in most US jurisdictions. Structural repairs to a home's foundation almost always require a building permit because they affect the structural integrity of the structure. Pier installation, carbon fiber wall repair, and underpinning are consistently permit-required work. Crack injection for cosmetic or waterproofing purposes is sometimes exempt. Confirm with your local building department before any work begins.
The permit requirement also protects you as a homeowner: permitted work is inspected by the building department, and the inspection creates a record of the repair that you can disclose to buyers. Unpermitted structural work may complicate home sales and refinancing. For a comprehensive review of when permits apply and how to handle the process, see when do you need a permit for home improvement.
How to Hire a Foundation Repair Contractor
Foundation repair is a specialized trade. Not every general contractor or waterproofing company has the equipment, training, or insurance to handle structural repair work. Steps to protect yourself:
- Get at least three quotes. Foundation repair pricing varies significantly between contractors. A three-quote comparison often reveals one outlier on each end.
- Ask for a written diagnostic report. A legitimate contractor can explain in writing why they are recommending a specific repair method and what they found during their inspection.
- Require a transferable warranty. Industry-standard pier warranties run 10 to 25 years and should be transferable to a new owner. Get the warranty terms in writing before signing.
- Verify contractor licensing. Foundation repair contractors should hold a general contractor license and, in most states, a structural specialty endorsement. Many also belong to the Foundation Repair Association (FRA) or similar trade groups that require training standards.
- Check insurance minimums. Require at least $1 million in general liability and active workers' compensation.
For the step-by-step process of hiring and vetting any major contractor, see how to hire a general contractor and review the specific license-checking steps in how to vet a contractor's license and insurance.
If you are also considering basement finishing after addressing a structural issue, the cost to finish a basement guide covers what comes after the foundation work is complete.
Frequently asked questions
What causes foundation problems in the first place?
The most common causes are soil expansion and contraction from moisture changes (called expansive soil), poor drainage that allows water to saturate soil under footings, tree roots displacing soil, and inadequate compaction of fill material under the slab during original construction. Drought conditions followed by heavy rain are a classic trigger for settlement cracking, especially in clay-rich soils common in Texas, Oklahoma, and the Southeast.
How do I tell if a foundation crack is serious?
Horizontal cracks indicate lateral soil pressure and may signal imminent structural failure -- the most serious type. Diagonal cracks at 45 degrees from corners suggest differential settlement. Vertical cracks under 1/4 inch wide that are stable and dry are usually shrinkage cracks. Any crack wider at the top, actively growing, or accompanied by bowing walls warrants immediate professional evaluation.
Does homeowners insurance cover foundation repair?
Standard homeowners insurance (HO-3) almost universally excludes foundation repair from settling, soil movement, or drainage failure -- considered maintenance issues, not sudden perils. Coverage applies only if a covered peril caused the damage (burst pipe, earthquake rider, or sudden collapse). Flood damage requires a separate NFIP flood policy. Review your policy exclusions before assuming coverage.
What is the difference between foundation underpinning and mudjacking?
Underpinning drives steel or concrete piers into stable soil or bedrock to permanently lift and stabilize the foundation, costing $1,000 to $3,000 per pier with most jobs needing 8 to 15 piers. Mudjacking injects pressurized slurry or polyurethane foam under a sunken slab to fill voids and raise it, costing $600 to $2,000 per section -- best for concrete slabs, not full foundation walls.
How long does foundation repair take?
Minor crack injection fills can be completed in one day. Pier installation for a typical home takes two to four days, including excavation, pier driving, and backfill. Full underpinning with drainage correction can take a week or more. Interior crack repair with carbon fiber straps for bowing walls typically takes one day per wall section. Most contractors will provide a specific timeline during the initial assessment.
Will foundation repairs affect my home's resale value?
A repaired foundation with documentation and a transferable warranty typically has less negative impact on resale value than a disclosed but unrepaired foundation issue. Most buyers and lenders require disclosure of known foundation problems. A properly completed repair with a 10-to-25-year transferable structural warranty is a strong selling point because it reduces buyer risk. Leaving a foundation problem unrepaired and hoping it goes unnoticed in a home inspection is almost never a viable strategy.