Foundation repair cost

Foundation repair costs $350 for a single injected crack and $7,000 to $30,000 for underpinning a settling house, with most piering projects landing near $16,000. The gap between those two numbers is the whole problem: the same visible crack can mean either one, and telling them apart is not something you can do from a photograph.

Before anything else, spend $400 to $1,500 on an independent structural engineer. Not the repair company's free inspection. An engineer who does not sell repairs has no reason to find work, and their report is what turns three wildly different quotes into three prices for the same defined scope.

What each repair costs

A typical house needing underpinning takes three to eight piers. A badly settled one takes eight to twelve. Engineering, permits and the lift itself add 10% to 20% on top of the pier count.

What the cracks are telling you

Not every crack is a foundation problem. Concrete shrinks as it cures and almost every foundation has hairline cracks from its first year.

Hairline vertical cracks, under about an eighth of an inch, that do not change. Shrinkage. Normal. Seal them if they leak, otherwise leave them.

Vertical cracks that are wider at one end. Differential settlement: one part of the foundation has moved more than another. Worth watching and measuring.

Horizontal cracks in a basement wall. The most serious kind. Soil pressure is pushing the wall inward, and horizontal cracking usually accompanies bowing. Get an engineer.

Stair-step cracks in block or brick. Follow the mortar joints. Common with settlement, and the width matters more than the pattern.

Cracks wider than a quarter inch, or with a height difference across them. Structural movement, not shrinkage.

The single most useful thing you can do is measure. Mark each end of a crack with a pencil, write the date, and measure the width with a feeler gauge or a crack monitor from a hardware store. A crack that has not moved in six months is a different problem from one that has grown a sixteenth of an inch. That measurement is worth more than any opinion.

Other signs of movement

• Doors and windows that stick or will not latch, especially several in one area
• Gaps opening between walls and ceilings, or between trim and walls
• Floors that slope noticeably, checkable with a marble or a long level
• Nails popping out of drywall in a line
• A chimney separating from the wall
• Gaps around window and door frames on the outside

One of these alone is often nothing. Three of them in the same corner of the house is a pattern.

Why foundations move

Water, almost always. Expansive clay soil swells when wet and shrinks when dry, and a house on clay in a region with wet winters and dry summers rides that movement every year. Poor drainage concentrates it.

Drought and trees. A large tree can pull hundreds of gallons a day out of the soil near a foundation. Foundation claims spike after dry summers.

Poor original compaction. Fill that was not compacted before the house was built keeps settling for decades.

Plumbing leaks under a slab, washing soil out from beneath it.

Excavation nearby, including a neighbour's project.

Notice how many of these are water. Fixing drainage is frequently cheaper than fixing the foundation, and it is always necessary alongside it, because underpinning a house without correcting what moved it means paying twice.

Reading a foundation quote

Foundation repair is the trade with the widest gap between honest firms and predatory ones, because the customer is frightened, the work is invisible once finished, and nobody gets a second opinion when they are told the house is unsafe.

Insist on:

• The engineer's scope, not the contractor's diagnosis
• The number of piers and their spacing, with a drawing
• Whether the price includes lifting the house back to level or only stabilising it
• What the drainage correction is, and whether it is included
• The warranty, whether it is transferable, and whether the company has been trading long enough for a 25 year warranty to mean anything
• Permit and engineering sign-off

Be wary of a same-day price that expires tomorrow, of anyone who will not put the pier count in writing, and of a free inspection that concludes with a $22,000 contract on the kitchen table.

Go deeper

Diagnose before you spend

• Structural engineer cost, and why an engineer does not sell repairs
• Foundation inspection cost, and the cheap diagnosis to do first
• Foundation repair cost by state, built from Bureau of Labor Statistics wage data

Structural repairs

• Foundation crack repair cost, and how to read what a crack is telling you
• Foundation pier cost for a settling house
• Bowing basement wall repair cost, the crack that needs a call today
• Carbon fiber strap cost, and the three bracing methods compared
• Mudjacking cost for a settled slab

Water

• Basement waterproofing cost, interior against exterior
• Wet basement repair cost, and the five cheap fixes to do first
• Drainage and grading cost, the cheapest structural insurance a house has
• French drain cost per linear foot
• Sump pump replacement cost, and why the backup is the whole point
• Window well cost, and why the drain is the point
• Basement dehumidifier cost

Crawl spaces

• Crawl space encapsulation cost
• Crawl space repair cost, and why vented crawl spaces were a mistake

Using the space

• Basement finishing cost, and why to fix the water first
• Basement flooring cost, and the free slab test
• Egress window cost, what makes a basement room a legal bedroom

Air quality

• Radon mitigation cost

Before you sign, and before you sell

• How long does a foundation last
• Does insurance cover foundation repair
• Selling a house with foundation problems

Frequently asked questions

Does homeowners insurance cover foundation repair?

Generally no. Standard policies exclude earth movement, settling and soil conditions. They may cover foundation damage caused by a covered peril, such as a plumbing leak that eroded soil under the slab, so identify the cause before assuming it is excluded.

Do I have to disclose foundation repair when I sell?

In most states, yes, as a known material defect, and prior repair usually has to be disclosed even after it is fixed. A transferable warranty and the engineer's report help considerably at that point, which is another reason to have both.

Will repair fix my cracked drywall and stuck doors?

Not by itself. Piering stabilises and sometimes lifts the foundation; the cosmetic damage above is a separate repair, usually $1,000 to $5,000. Do it a few months after the structural work so the house has settled into its new position.

Can I wait?

Sometimes, and monitoring is a legitimate strategy for slow movement. Measure the cracks monthly. Movement that stops through a full wet and dry cycle may not need anything. Movement that continues gets more expensive to correct the longer it runs.

How long does the work take?

Crack injection, a few hours. Carbon fibre straps, one to two days. Piering, three to seven days for a typical house. Interior drainage, two to five days. Exterior excavation, one to two weeks.