What slab foundation repair costs
Most homeowners pay $2,500 – $10,000 to repair a slab foundation. That band is wide because it covers two jobs that have almost nothing in common except the word "slab."
The first is lifting concrete back into place after the soil beneath it washed out or compressed. That is $700 – $2,100 per section, done in a few hours through holes about the size of a coin. The second is underpinning — transferring the weight of the house onto piers driven down to soil that can carry it. That is priced per pier at $1,250 – $3,100, and the pier count is what turns a repair into a five-figure project.
Figuring out which of the two you need is the entire question, and it is worth spending $450 – $600 on an independent structural engineer to answer it rather than accepting the answer from whoever wants to sell you the work.
Slab repair cost by line item
| Line item | Typical range | Unit | What drives it |
|---|---|---|---|
| Slab jacking (lift a sunken section) | $700 – $2,100 | per section | Area lifted, void size, material choice |
| Slab crack repair, interior | $500 – $1,600 | per crack | Flooring removal and replacement |
| Steel push pier | $1,250 – $2,400 | per pier | Depth to load-bearing soil |
| Helical pier | $1,400 – $3,100 | per pier | Torque depth and equipment access |
| Concrete pressed piling | $900 – $1,700 | per pier | Regional method, shallower reach |
| Polyurethane foam jacking | $5 – $25 | per sq ft | Lift height and injection volume |
| Cosmetic restoration after lifting | $1,000 – $5,000 | per house | Drywall, trim, tile and paint |
| Structural engineer’s report | $450 – $600 | per visit | Independent of any contractor |
| Permit | $75 – $400 | per project | Municipality and structural review |
Source: Compiled from 2025–2026 residential foundation contractor pricing datasets and concrete lifting supplier rates, normalized to installed cost including labor, access and cleanup. · Last reviewed July 30, 2026 · Reference data · How we compile these figures
Pier prices carry a hidden variable: depth. A push pier is driven until it refuses, which might be 12 feet in one yard and 28 feet across town. Contractors who quote a flat per-pier price are averaging that risk into their number; contractors who quote a base price plus a per-foot adder are exposing it. Both are legitimate — ask which you are getting so the invoice holds no surprises.
Cost by what is wrong with your slab
| The problem | Typical cost | Approach | What is going on |
|---|---|---|---|
| Thin meandering crack in the slab surface | $0 – 600 | monitor or seal | Shrinkage. Often needs nothing |
| One sunken section, patio or garage | $700 – 2,100 | slab jacking | Void under the slab, structure above unaffected |
| Settled corner of the house | $5,000 – 14,000 | 4 – 6 piers | Soil under one footing gave way |
| One full side of the house dropping | $10,000 – 30,000 | 8 – 12 piers | Drainage or clay cycling on that elevation |
| Movement around the whole perimeter | $25,000 – 60,000 | 20+ piers | Site-wide soil failure; engineer sets spacing |
| Plumbing leak washing out soil under the slab | $4,000 – 20,000 | leak + repair | Line location, tunneling vs breaking the slab |
Source: Scope bands built from pier counts on typical residential slab projects at 6–8 ft spacing, plus concrete lifting rates by section. Plumbing figures include leak location and access, excluding restoration. · Last reviewed July 30, 2026 · Reference data · How we compile these figures
The top row is the one worth reading twice. A slab-on-grade floor rests on the ground rather than carrying the house, so a thin wandering crack in it is usually curing shrinkage. It becomes structural when one side of the crack sits lower than the other, when water pushes up through it, or when it lines up with a crack running up a wall above.
Lifting or underpinning — how the choice is made
Lifting fills a void. Underpinning replaces failed support. They solve different failures, so the price gap between them reflects the problem rather than the ambition of the contractor.
- Slab jacking or foam is right when the concrete dropped into a void while the soil around and beneath it is otherwise sound. Driveways, patios, garage floors and sidewalks are the classic cases. Mudjacking costs $3 – $6 per square foot; polyurethane foam runs $5 – $25 per square foot and weighs a fraction as much, which matters on soil that already proved it cannot carry weight.
- Piers are right when the soil supporting the footing has failed and will keep failing. Filling a void in that situation buys a season or two. Piers go in along the affected footing at 6 – 8 foot spacing, and that spacing decision is worth more money than any other line in the bid: on a 60-foot side, 6-foot spacing versus 8-foot spacing is roughly four extra piers, or about $5,000 – $12,000.
That is precisely why an engineer sets the spacing rather than the company installing the piers. The engineer has no financial stake in the answer.
When you can leave a slab alone
A meaningful share of slab worry ends with no repair at all, and these checks are free.
- Hairline floor cracks under 1/8 inch, faces flush. Concrete shrinks as it cures. Mark the ends with a pencil and the date, re-check after a wet season and a dry one. Stable means done moving.
- Settlement that finished years ago. A house that dropped half an inch in 1998 and held still since needs cosmetic patching, not piers. Photograph a level on the floor, note the reading, repeat in six months. Two identical readings save you five figures.
- A sunken patio or sidewalk detached from the house. This is a trip hazard and an appearance problem, priced accordingly at $700 – $2,100. It carries no structural meaning for the house itself.
- Doors sticking in one room only. That is usually humidity or a hinge, and it costs an hour with a screwdriver. Foundation movement shows up as a cluster across multiple rooms in one direction.
- Drainage you have never adjusted. Extending downspouts and regrading soil away from the wall costs $100 – $600 and addresses the cause behind a surprising number of slab problems before they need piers.
Getting three bids you can actually compare
Slab quotes vary by thousands on identical houses, and three things explain most of it: pier count and spacing, whether the engineer’s report and permit are inside the price, and whether concrete, landscaping and interior restoration are in scope. Ask every contractor to itemize those three and the spread usually explains itself.
Get the independent engineer’s report first for anything priced above roughly $5,000. It costs $450 – $600, it converts a sales visit into a specification, and it frequently comes back with a smaller scope than a free inspection proposed. It also gives you a document to hand a future buyer, which is worth something on its own.
One more item belongs in every slab conversation: if a plumbing leak under the slab caused the soil loss, fix the leak first. Piers installed over an active leak stabilize the house while the water keeps working on the next section of soil.
Where to go next
- Foundation repair cost — the full itemized guide across every repair type.
- Underpinning cost — per-pier pricing and how pier count is decided.
- Mudjacking cost — slab lifting priced per square foot, and how foam compares.
- House leveling cost — what full releveling costs on a slab.
- Cost calculator — itemized estimate for your inputs, free.