Hairline cracks in concrete
Concrete shrinks as it cures and cracks doing so. Fine, stable, non-displaced cracks in a slab or wall are extremely common and usually not structural.
Foundation repair · independent publisher
Which cracks matter, when to call a structural engineer, how piers, slab lifting and waterproofing differ, and what moves the price. Then tell us what you are seeing and we will follow up about foundation companies serving your area.
Not a contractor. We do not inspect, engineer or repair foundations, and no company pays to appear here.
Sources on the page. Code, soil and insurance statements cite the model code, the agency or the policy, with a date.
Your numbers. 12 free tools ask for your figures instead of printing a national price.
Your details stay yours. Nothing goes to a foundation company unless you agree. Submitting is not a contract.
The short answer
There is no honest national average for foundation repair, because the same crack can need a downspout extension or two dozen piers.
The scope is the price. Method, pier count, depth to bearing soil, access, soil, plumbing tests and making good set the number. Ask every company to bid the same written scope, ideally an engineer’s.
Foundation services
Six guides, each built the same way: when you need the work, what a professional checks, what the job involves, what moves the price and what to ask before you sign.
Where to start
Nearly every house has cracks, and most mean nothing. The pattern, the width, the direction and whether it is changing tell you which ones do.
Concrete shrinks as it cures and cracks doing so. Fine, stable, non-displaced cracks in a slab or wall are extremely common and usually not structural.
Following the mortar joints in brick or block. Worth attention, particularly if the two sides are offset rather than just separated.
The one to take seriously. A horizontal crack, especially with inward bowing, suggests lateral soil pressure rather than settlement.
Windows and doors concentrate stress. Diagonal cracks running from their corners are a common early sign of differential movement.
Frames going out of square. Useful because it is a whole-house symptom rather than a local one — though humidity does it too.
Slope points at settlement or a failing support below. Bounce without slope is more often a framing or joist issue than a foundation one.
The single most valuable piece of information. Date and photograph a crack, or bridge it with a marked gauge, and look again in a few months.
Separation where walls meet ceilings or where trim pulls away is differential movement showing up in the finishes.
Poor drainage, downspouts discharging at the wall and negative grade cause more foundation movement than any other single factor.
What moves the price
We do not publish an average repair price. We publish what moves it, so you can make two bids describe the same job.
How it works
Cracks, sloping floors, a bowing wall or an inspection before you buy — plus the zip code so we know which local companies are relevant.
Start the formWe follow up about connecting you with foundation professionals serving your area. Nothing is sent to a company unless you agree.
How matching worksAsk each company to bid the same written scope: method, pier count, assumed depth, target lift and warranty terms.
How to compare bidsPick the foundation company that matches the diagnosis, the timeline and the way you want the work run — or keep researching.
Read the warranty firstFree tools and guides
Get connected
Three short steps: the problem, your home, and how to reach you. Nothing goes to a foundation company unless you agree.
A straight answer first. Our matching is still being built, so this is not an instant quote form.
Tell us what you see and we will help you work out whether you need an engineer, a drainage fix, or a dated photo to check again in six months.
Find a Foundation Professional
Tell us what you are seeing and where you are. We will follow up about connecting you with foundation professionals serving your area.
Questions
We read what you sent (the problem, the zip code and your notes) and follow up about next steps. Company matching is still being built, so this is not an instant quote. Your details are never sold, and no contractor receives them unless you agree.
Yes. Submitting the form is free and does not commit you to a company, a repair method or a start date. You decide whether to talk to anyone and whether to hire.
Usually not. Fine, stable hairline cracks in concrete are mostly shrinkage from curing. Take a crack seriously if it is wide, offset side to side, horizontal in a basement wall, paired with bowing, or widening over time. Photograph and date it: change tells you more than looks.
Because the soil under them moves. Expansive clay swells when wet and shrinks when dry, poor drainage soaks the ground unevenly, large trees draw water from beneath the house, and hidden plumbing leaks keep one area wet. The concrete follows the ground, so fixing water is part of most real repairs.
An engineer, and one you pay yourself. A licensed engineer measures the house, states the cause and specifies a scope, with no stake in how many piers get installed. That report is then what every contractor bids against, which is what makes three quotes comparable.
There is no useful national average, because the scope runs from a downspout extension to underpinning a whole wall. Method, pier count, depth to bearing soil, access, soil, plumbing tests and making good set the price. Two bids compare only if they state the same method, pier count and depth.
Usually not. Standard policies commonly exclude earth movement, settling and soil damage. Damage caused by a sudden covered event, such as a plumbing leak, may be treated differently, and coverage varies by policy and state. Read your policy and ask your insurer before assuming either way.
Often, yes, and it is a sensible first step. Extend downspouts well away from the wall, regrade soil that slopes toward the house, and keep irrigation off the foundation. Photograph and measure the cracks before and after so you can tell whether it worked.
Settlement is part of the house moving down because the soil under it compressed. Heave is soil swelling and pushing part of the house up, usually expansive clay taking on water. The cracks can look alike, but the fixes go in opposite directions, so the cause comes before the method.
Only as much as the company behind them. Check what is covered (often just the piers installed), whether it transfers to a buyer, and what conditions apply, such as keeping drainage in order. A transferable warranty from an established company helps at resale; a lifetime promise from a new one is only a promise.
Undisclosed movement hurts more. A problem that was diagnosed, repaired and documented with an engineer’s report and a transferable warranty is a manageable disclosure. Unexplained cracks with no paperwork are what worry buyers and their inspectors.
Installing piers along a typical house wall often takes days rather than weeks, though access, depth and weather change that. The longer parts usually surround it: the engineering, any permit, and putting floors, landscaping and finishes back afterward.
More in the full FAQ, or read who we are and how we are paid and how we vet professionals.
Contact
Write to us about a correction, a question on a guide, or how the site is paid for. We read every message.
We are not a foundation repair company, and no photograph settles whether movement matters — that needs someone on site.