Foundation Repair Methods: How Each One Works, What It Costs and Which You Need

Foundation repair methods are the techniques used to seal, strengthen, support or lift a foundation that has cracked or moved. Most fall into five groups: sealing cracks, lifting slabs, bracing walls, supporting footings, and lifting the whole house. Each one solves a different problem, so the right method depends on what moved and why.

If a contractor has just recommended piers and you have no way to tell whether you need them, you are not alone. Most homeowners see this work once in a lifetime, and the sales advice is rarely independent. In this guide I will explain how each method works, what it costs in 2026, how to match it to your problem, and what to ask before you sign.

How Do You Choose a Foundation Repair Method?

Good repair starts with diagnosis, not with a product. Below I am sharing the four questions that decide the method.

1. What moved? A crack, a wall, a slab, a footing or a pier each points to a different foundation repair.
2. Which way did it move? Downward movement needs additional support, and sideways movement needs bracing against the soil.
3. Is it still moving? A stable crack may need only sealing, while active movement needs its cause fixed.
4. Why did it move? Water, clay soil, poor fill and tree roots all need attention, or the repair may fail.

Below I am sharing the main methods side by side in a table.

As the table shows, the cost climbs as the repair moves from the surface down into the ground. Except for wall anchors, which come from Modernize, these prices come from This Old House, updated October 2026.

How Are Foundation Cracks Repaired?

Crack repair seals a gap and keeps water out. Epoxy bonds the two sides of a stable crack, while polyurethane foam stays flexible and suits leaks. Neither one stops a wall or footing from moving. For that reason, a crack that is growing, horizontal or offset needs its cause diagnosed before anyone seals it.

How Are Sunken Slabs Lifted?

Crews drill small holes and pump material under a slab to raise it. Mudjacking uses a cement slurry, while polyjacking uses expanding foam that weighs far less. Foam costs more per square foot, but it suits weak or wet soil. Our guide to mudjacking vs polyjacking compares cost, weight and lifespan.

Slab lifting raises the concrete and fills the gap. It does not stop soil from sinking further, so it fits a slab that has dropped after poor compaction or a washout, and it may not fit a house that is still settling.

How Are Bowing Walls Fixed?

A bowing wall is being pushed by the soil outside, so the repair has to resist that force. Below I am sharing the options, from lightest to heaviest.

1. Carbon fiber straps: Strips bonded to the interior wall surface hold the wall in its current position without straightening it.
2. Steel beams: Vertical beams fastened to the basement floor and the joists brace the wall against further movement.
3. Wall anchors: Rods run through the wall to plates in the yard, and they can pull it back over time.
4. Helical tiebacks: Steel shafts are screwed through the wall into firm soil.
5. Excavate and rebuild: Crews remove the backfill, then straighten, reinforce or replace the damaged wall section.

Our bowing basement wall guide explains how far a wall can move and which repair fits each stage.

Push Piers vs Helical Piers: How Is a Sinking Foundation Supported?

When the soil under a footing is the problem, piers move the weight past it. This is called underpinning. Below I am sharing the two common steel systems in a table.

As the table shows, the two systems reach the same goal in different ways, and the house and soil decide which one fits. Family Handyman reports typical helical pier spacing of six to nine feet on a house. Ask how the pier count was worked out, because the count drives the price.

Example: Suppose one 30-foot side of a house has settled. Piers at about 7.5-foot spacing give 5 piers. At $1,000 to $3,000 each, that is $5,000 to $15,000. Add about $600 for an engineer's inspection, and your budget is about $5,600 to $15,600 before any drainage work or finishes.

How Are Pier and Beam Foundations Repaired?

A house on piers and beams is usually repaired from below. Crews re-shim loose beams, add or replace piers, and replace rotted wood. Typical repairs cost $3,000 to $9,500. Moisture is the main enemy, so a dry crawl space is part of the repair. Our guide to the pier and beam foundation covers each repair in detail.

What Happens During a Foundation Repair?

Knowing the usual sequence helps you judge a contractor's plan and prepare your home. Below I am sharing the typical stages of a structural foundation repair.

1. Assessment: An engineer or contractor measures floor elevations, records cracks and identifies the cause of the movement.
2. Scope and permit: The repair scope is written down, and the contractor or homeowner obtains any permit the local building department requires.
3. Site preparation: Crews mark buried utilities, protect landscaping and clear furniture away from the affected foundation walls.
4. Installation: Crews excavate beside the footing, fix brackets, and install the piers, anchors or wall reinforcement.
5. Adjustment: Any lifting happens slowly, with elevation readings taken throughout, and it stops at the target agreed in the scope.
6. Backfill and inspection: Crews compact the soil, restore drainage away from the house, and arrange any required inspection.
7. Paperwork: You receive the final invoice, the permit sign-off and the written warranty, which a future buyer will want to see.

What Else Goes Into a Foundation Repair Quote?

The method is only part of the price. This Old House lists several extras. Below I am sharing the ones to ask about.

1. Labor: This Old House puts it at around $200 per hour.
2. Permits: These can add $75 to $150, and some towns require several inspections.
3. Engineer and soil reports: Serious damage may need one or both.
4. Unseen obstacles: Tree roots and old debris can appear once digging starts.
5. Drainage: A repair that leaves the water in place leaves the cause in place.
6. Finishes: Drywall, flooring and landscaping are often left out.

Our repair quote checklist shows how to compare quotes line by line.

So, Which Foundation Repair Do You Need?

The answer depends on what you see.

1. If a thin crack leaks but has stopped moving: Correct the drainage outside, then inject the crack from inside the basement.
2. If a walkway or garage slab has dropped: Compare mudjacking and polyurethane foam on price, weight and expected lifespan.
3. If a wall has a small bow: Ask about straps or beams while the wall is still close to plumb.
4. If a corner of the house has sunk: Get an engineer's assessment, then quotes for piers.
5. If a pier and beam floor sags: Look underneath before you assume the worst.
6. If you are unsure: Pay for an independent inspection before you pay for a repair.

What You Should Do: Write down what moved, which way, and whether it is still moving. Take those answers to an engineer, then ask contractors to quote that scope.

Common Mistakes to Avoid With Foundation Repair

1. Letting a salesperson diagnose the problem: The diagnosis should come before the product.
2. Sealing a moving crack: The crack reopens because the underlying movement continues.
3. Ignoring drainage: Water around the foundation is a common cause of movement, and a repair does not remove it.
4. Comparing totals only: Pier counts, depths and repair scopes differ considerably between contractors.
5. Lifting too fast or too far: Rapid lifting damages interior finishes, plumbing connections and door frames.
6. Skipping permits: Unpermitted structural work creates problems with inspectors and buyers when you eventually sell.
7. Accepting a warranty without reading it: Check the covered components, the exclusions and the transfer conditions.

Conclusion

Foundation repair methods differ because foundations fail in different ways. Injection seals cracks, slab lifting raises concrete, straps and anchors brace walls, and piers support sinking footings. Match the method to what moved, fix the water behind it, and compare quotes on one scope. For more help, read our independent comparisons of foundation repair options.

Sources and Standards

1. This Old House, Foundation repair cost, updated October 2026.
2. Family Handyman, Helical piers, updated February 8, 2024.
3. Modernize, Bowing basement wall repair cost, updated August 2026.
4. This Old House, How much does a foundation inspection cost?, 2026.
5. Concrete Masonry and Hardscapes Association, TEK 15-01B, Allowable stress design of concrete masonry foundation walls.
6. National Association of Home Builders, W. Keaveny, PE, Misconceptions about the common crack, January 2018.